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TEST1.
1. What composes all matter whether a liquid,
solid, or gas?
A. Atoms
B. Electrons
C. Protons
D. Neutrons
ANSWER: A
2. Which of the following is not a basic part of
an atom?
A. Electron
B. Proton
C. Neutron
D. Coulomb
ANSWER: D
3. What is the smallest element of a matter?
A. atom
B. molecule
C. crystal
D. wafer
ANSWER: A
4. To determine whether a material can
support the flow of electricity or not, we
need to examine its
A. atomic structure
B. physical state
C. molecular structure
D. chemical composition
ANSWER: A
5. Approximate diameter of an atom
A. 10-10 µµm
B. 10-10 µm
C. 10-10 mm
D. 10-10 m
ANSWER: D
6. The lightest kind of atom or element
A. Helium
B. Oxygen
C. Hydrogen
D. Titanium
ANSWER: C
7. Known as the simplest type of atom.
A. Hydrogen
B. Oxygen
C. Helium
D. Nitrogen
ANSWER: A
8. Approximate diameter of a Hydrogen atom
A. 1.1 x 10-10 µµm
B. 1.1 x 10-10 µm
C. 1.1 x 10-10 mm
D. 1.1 x 10-10 m
ANSWER: B
9. A commonly used model in predicting the
atomic structure of a material.
A. String model
B. Wave model
C. Particle model
D. Bohr model
ANSWER: D
10. Is at the center of an atomic structure in a
Bohr model.
A. electrons
B. protons
C. neutrons
D. nucleus
ANSWER: D
11. The nucleus of an atom is normally
A. neutral
B. positively charged
C. negatively charged
D. either positively or negatively
charged
ANSWER: A
12. What particles that revolve around the
positive nucleus?
A. electrons
B. protons
C. neutrons
D. electrons & protons
ANSWER: A
13. In electricity, positive electric charge refers
to ____________.
A. protons
B. neutrons
C. electrons
D. atoms
ANSWER: A
14. What is the charge of an electron?
A. 1.6022 x 10-19 C
B. 9.1096 x 10-19 C
C. 1.6022 x 10-31 C
D. 9.1096 x 10-31 C
ANSWER: A
15. The mass of a proton is approximately
A. 1.6726 x 10-19 Kg
B. 1.6726 x 10-27 Kg
C. 1.6022 x 10-19 Kg
D. 1.6022 x 10-27 Kg
ANSWER: B
16. Protons are about _________ heavier than
electrons.
A. 1,800 times
B. less than thrice
C. less
D. twice
ANSWER: A
17. Approximately, how many electrons that
could equal to the mass of a single proton or
neutron?
A. 1,863 electrons
B. 1,683 electrons
C. 1,638 electrons
D. 1,836 electrons
ANSWER: D
18. The maximum number of electrons (Ne)
that can occupy a given shell (n) is
determined by the formula
A. Ne = 2n2
B. Ne = n2
C. Ne = 2n
D. Ne = 2n
ANSWER: A
19. The discrete amount of energy required to
move an electron from a lower shell to a
higher shell.
A. negative energy
B. positive energy
C. quantum
D. quanta
ANSWER: C
20. Maximum number of orbiting electrons at
the first or K shell
A. 2
B. 4
C. 6
D. 8
ANSWER: A
21. Electron is derived from the Greek name
elektron which means
A. huge
B. tiny
C. particle
D. amber
ANSWER: D
22. Electric charge of neutron is the same as
A. proton
B. electron
C. current
D. atom
ANSWER: D
23. In an atomic structure, what particle that
has no charge and therefore has no effect
on its atomic charge
A. electrons
B. protons
C. neutrons
D. nucleons
ANSWER: C
24. The atomic number of an element is
determined by the number of
A. electrons
B. valence electrons
C. protons
D. protons or neutrons
ANSWER: C
25. The atomic weight of an element is
determined by the number of
A. electrons
B. valence electrons
C. protons
D. protons and neutrons
ANSWER: D
26. If an element has an atomic number of 12,
there are how many protons and electrons?
A. 6 protons and 12 electrons
B. 12 protons and 6 electrons
C. 12 protons and 12 electrons
D. 12 protons and 24 electrons
ANSWER: C
27. Suppose there is an atom containing eight
protons and eight neutrons in the nucleus,
and two neutron are added to the nucleus,
the resulting atomic weight is about
A. 8
B. 10
C. 16
D. 18
ANSWER: D
28. It is composed of a series of energy levels
containing the valence electrons.
A. conduction band
B. forbidden band
C. side band
D. valence band
ANSWER: D
29. Electrons at the conduction band are called
A. free electrons
B. valence electrons
C. deep state electrons
D. shallow state electrons
ANSWER: A
30. _____________ are electrons at the outer
shell
A. Inside shell electrons
B. Conductor electrons
C. Outside shell electrons
D. Valence electrons
ANSWER: D
31. Electrons at the outermost shell are called
A. free electrons
B. valence electrons
C. deep state electrons
D. shallow state electrons
ANSWER: B
32. Which material has more free electrons?
A. Conductor
B. insulators
C. mica
D. dielectric
ANSWER: A
33. Which material has the least number of
valence electrons?
A. conductor
B. semiconductor
C. insulator
D. semi-insulator
ANSWER: A
34. What elements possess four valence
electrons?
A. Insulators
B. Semi-insulators
C. Semiconductors
D. Conductors
ANSWER: C
35. A good conductor has how many valence
electrons?
A. 1
B. 2
C. 4
D. 8
ANSWER: A
36. Materials that might have eight valence
electrons
A. conductor
B. insulator
C. semiconductor
D. semi-insulator
ANSWER: B
37. An insulating element or material has
capability of _________.
A. conducting large current
B. storing voltage
C. storing high current
D. preventing short circuit between
two conducting wires
ANSWER: D
38. A law of nature makes certain materials
tend to form combinations that will make
them stable. How many electrons in the
valence orbit are needed to give stability?
A. 1
B. 2
C. 4
D. 8
ANSWER: D
39. Determine which statement is true?
A. The current carriers in conductors
are protons.
B. The current carriers in conductors
are valence electrons.
C. Valence and inner electrons are the
carriers in conductors.
D. Valence electrons are not the ones
that become free electrons.
ANSWER: B
40. A material that contains an abundance of
free carrier is called
A. insulator
B. semi-insulator
C. conductor
D. semiconductor
ANSWER: C
41. From the combined energy-gap diagram,
which material has the widest gap between
valence band and the conduction band?
A. conductor
B. semiconductor
C. super conductor
D. insulator
ANSWER: D
42. From the combined energy-gap diagram,
which material has the smallest energy gap
between valence band and the conduction
band?
A. conductor
B. semiconductor
C. super conductor
D. insulator
ANSWER: A
43. __________ has a unit of electronvolt(eV).
A. Charge
B. Potential difference
C. Energy
D. Current
ANSWER: C
44. The difference in energy between the
valence and conduction bands of a
semiconductor is called
A. band gap
B. extrinsict photoeffect
C. conductivity
D. energy density
ANSWER: A
45. The energy gap between the valence band
and conduction band of a conductor is in the
order of
A. zero electron volt (0 eV)
B. one electron volt (1 eV)
C. five electron volt (5 eV)
D. ten electron volt (10 eV)
ANSWER: A
46. The energy gap of an insulator is in the
order of
A. zero electron volt (0 eV)
B. one electron volt (1 eV)
C. five electron volt (5 eV)
D. one-tenth electron volt (0.1 eV)
ANSWER: C
47. In materials, what do you call the region
that separates the valence and conduction
bands?
A. energy gap
B. forbidden band
C. insulation band
D. energy gap or forbidden band
ANSWER: D
48. What do you call the potential required to
remove a valence electron?
A. valence potential
B. threshold potential
C. critical potential
D. ionization potential
ANSWER: D
49. A factor that does not affect the resistance
of the material.
A. atomic structure
B. mass
C. length
D. cross-sectional area
ANSWER: B
50. Copper atom has how many protons?
A. 1
B. 4
C. 8
D. 29
ANSWER: D
51. Ion is __________.
A. an atom with unbalanced charges
B. free electron
C. proton
D. nucleus without protons
ANSWER: A
52. What will happen to an atom if an electron is
either taken out or taken into the same
atom?
A. Becomes negative ion
B. Becomes positive ion
C. Becomes an ion
D. Nothing will happen
ANSWER: C
53. When an atom gains an additional
_________, it results to a negative ion.
A. neutron
B. proton
C. electron
D. atom
ANSWER: C
54. An electrical insulator can be made a
conductor by
A. ionizing
B. electroplating
C. oxidizing
D. metalization
ANSWER: A
55. Refers to the lowest voltage across any
insulator that can cause current flow.
A. conduction voltage
B. breakdown voltage
C. voltage flow
D. voltage drop
ANSWER: B
56. Dielectric is another name for
A. conductor
B. semiconductor
C. insulator
D. semi-insulator
ANSWER: C
57. When all atoms of a molecule are the same,
the substance is called
A. a crystal
B. an element
C. a compound
D. an ion
ANSWER: B
58. An isotope
A. has a negative charge
B. has a positive charge
C. might have either positive or
negative charge
D. is neutral
ANSWER: D
59. Isotope means, the same element but with
different number of
A. electrons
B. neutrons
C. protons
D. atoms
ANSWER: B
60. The particles that make up the lattice in
ionic crystal
A. molecules
B. ions
C. electrons
D. neutrons
ANSWER: C
61. A structure for solids in which the position of
atoms are predetermined
A. Crystalline
B. Polycrystalline
C. Lattice
D. Non-Crystalline
ANSWER: A
62. A solid, which has no defined crystal
structure.
A. Crystalline
B. Non-crystalline
C. Amorphous
D. Non-crystalline or Amorphous
ANSWER: D
63. States that each electron in an atom must
have a different set of quantum numbers.
A. Quantum principle
B. Fermi-Dirac principle
C. Spin principle
D. Exclusion principle
ANSWER: D
64. Given an atomic structure of a certain
material, what data can you determine out
from it?
A. atomic number
B. atomic mass
C. the number of protons and
electrons
D. all of the above
ANSWER: D
65. Ideally, all atoms have the same number of
positively charged protons and negatively
charged electrons, and is therefore
considered as
A. electrically neutral
B. physically stable
C. magnetically aligned
D. technically rigid
ANSWER: A
66. When the charge of an atom becomes
unbalanced, the atom is said to carry
A. Electric charge
B. Magnetic charge
C. Electromagnetic charge
D. Electrical current
ANSWER: A
67. A charged atom is also known as
A. ion
B. anion
C. cation
D. domain
ANSWER: A
68. An atom or group of atoms that carries a
net electric charge is called
A. ion
B. anion
C. cation
D. domain
ANSWER: A
69. A negative ion results when an atom
A. loss some of its inside electrons
B. loss some of its valence electrons
C. gains additional electron
D. gains additional proton
ANSWER: C
70. A positive ion has
A. excess of electrons
B. excess of neutrons
C. lack of electrons
D. lack of protons
ANSWER: C
71. What do you call a positively charged ion?
A. cathode
B. anion
C. cation
D. domain
ANSWER: C
72. What do you call a negatively charged ion?
A. electron
B. anion
C. cation
D. domain
ANSWER: B
73. __________ is the procedure by which an
atom is given a net charge by adding or
taking away electron.
A. Polarization
B. Irradiation
C. Ionization
D. Doping
ANSWER: C
74. Is a process by which an atom is constantly
losing and then regaining electrons?
A. oxidation
B. passivation
C. metallization
D. ionization
ANSWER: D
75. The process in which atoms are changed
into ions.
A. oxidation
B. passivation
C. metallization
D. ionization
ANSWER: D
76. Gases with charged particles.
A. inert
B. plasma
C. conductive
D. reactive
ANSWER: B
77. One Coulomb of charge has how many
electrons?
A. 6.24 x 1018 electrons
B. 6.24 x 1019 electrons
C. 62.4 x 1018 electrons
D. 62.4 x 1019 electrons
ANSWER: A
78. Coulomb is the SI unit of charge, how about
in cgs?
A. Statcoulomb
B. electron volt
C. electron unit
D. static unit
ANSWER: A
79. Statcoulomb is also known as
A. electrostatic unit (esu)
B. electron volt
C. electron unit
D. static unit
ANSWER: A
80. An isolated body under normal condition is
always
A. neutral
B. positively charged
C. negatively charged
D. ionized
ANSWER: A
81. What is the charge magnitude, Q of a body
if it lacks 5 electrons?
A. 5 x 10-19 Coulomb
B. 5 Coulomb
C. 8 x 10-19 Coulomb
D. 19 x 10-19 Coulomb
ANSWER: C
82. The net movement of charged particles in
one direction or another.
A. flow
B. current
C. drift current
D. diffusion current
ANSWER: B
83. The rate at which electrons pass a given
point in the circuit gives the magnitude of
A. electron current
B. magnetic current
C. drift current
D. diffusion current
ANSWER: A
84. The unit of current.
A. Ampere
B. Ampere/sec.
C. Ampere-sec.
D. Ampere-hr.
ANSWER: A
85. The unit Ampere is equivalent to
A. one Coulomb/second
B. one Coulomb/min
C. one Joule/sec
D. one Joule/min
ANSWER: A
86. When one coulomb of electric charge
continuously passes a given point every
second, the electric current is said to
A. 1 µA
B. 1 mA
C. 1 A
D. 10 A
ANSWER: C
87. One ampere is equal to how many electrons
per second?
A. 1 x 1018 electrons/sec.
B. 1 x 1019 electrons/sec.
C. 6.25 x 1018 electrons/sec.
D. 6.25 x 1019 electrons/sec.
ANSWER: D
88. The bigger the diameter of a wire,
A. more current can pass
B. less current can pass
C. more heat is generated when
current flow
D. the higher is the electrical
resistance
ANSWER: A
89. If in a material, current can hardly pass, it
means
A. the material is very hard
B. the material is very soft
C. the material has high resistance
D. the material has less resistance
ANSWER: C
90. The greater the diameter of a wire, the
_______ is the resistance.
A. greater
B. lesser
C. harder
D. bigger
ANSWER: B
91. The longer the wire the ________ is the
resistance
A. higher
B. lesser
C. harder
D. smaller
ANSWER: A
92. If a conductor’s cross-sectional area is
doubled and its length is halved, the value
of its resistance will
A. double
B. quadruple
C. decrease by a factor of two
D. decrease by a factor of four
ANSWER: D
93. The amount of resistance that a wire has
with regards to the flow of electric current
A. is less for a conductor than for an
insulator
B. is less for an insulator than for a
semiconductor
C. is less for a semiconductor than for
a conductor
D. is high for a semiconductor than for
an insulator
ANSWER: A
94. The area of a conductor whose diameter is
0.001 inch is equal to
A. one angstrom
B. one circular mil
C. one micron
D. one steradian
ANSWER: B
95. A 100m long wire with a cross-sectional
area A=10-3 m2 has a resistance of 10Ω.
Determine the resistivity of the wire.
A. 10-2 Ω-m
B. 10-3 Ω-m
C. 10-4 Ω-m
D. 10-5 Ω-m
ANSWER: C
96. the reciprocal of resistance
A. permeance
B. elastance
C. inductance
D. conductance
ANSWER: D
97. The science of physical phenomena at very
low temperature, approaching absolute zero
is called ________.
A. crytanalysis
B. cybernetics
C. temperature inversion
D. cryogenics
ANSWER: D
98. What happens in the resistance of copper
wire when its temperature is raised?
A. decreased
B. steady
C. increased
D. zero
ANSWER: C
99. A wire has a resistance of 5Ω at room
temperature and a temperature coefficient
α=4x10-3/°C, calculate the wire resistance
at 75°C.
A. 8.925 Ω
B. 7.925 Ω
C. 6.925 Ω
D. 6.050 Ω
ANSWER: D
100. The temperature coefficient of resistance
of a certain wire is known to be 0.004/°C
at zero degrees Celsius. What would be
the temperature coefficient at room
temperature?
A. 0.00018/°C
B. 0.00036/°C
C. 0.00180/°C
D. 0.00360/°C
ANSWER: D
101. Where does practically all of the RF
current flow in a conductor?
A. along the surface
B. in the center of the conductor
C. in the electromagnetic field in the
conductor center
D. in the magnetic field around the
conductor
ANSWER: A
102. ________ is one factor that does not
affect resistance.
A. Cross sectional area
B. Resistivity
C. Mass
D. Length
ANSWER: C
103. Why is the resistance of a conductor
different for RF current than for DC?
A. Because of skin effect
B. Because conductors are non-linear
devices
C. Because the insulation conducts
current at radio frequency
D. Because of the Heisenberg effect
ANSWER: A
104. The ability of a material to resist current
flow is called “resistance”. What is (are)
the factor(s) that affect its value?
A. temperature
B. length & cross-sectional area
C. atomic structure
D. all of these
ANSWER: D
105. Find the charge in coulombs of dielectric
that has a positive charge of 14.5 x 10 to
the 18th power protons.
A. 29 x 10 to the 16th Coulombs
B. 14.5 x 10 to the 16th Coulombs
C. 14.5 x 10 to the 18th Coulombs
D. 29 x 10 to the 18th Coulombs
ANSWER: C
106. Electron volt (eV) is a unit of
A. power
B. energy
C. magnetic field
D. magnetic force
ANSWER: B
107. One electron volt (eV) is equivalent to
A. 1.0 watt-sec
B. 1.6 x 10-19 watt-sec
C. 1.0 Joule
D. 1.6 x 10-19 Joules
ANSWER: D
108. What law that describes the force of
attraction or repulsion between two
charges is directly proportional to their
strengths and inversely proportional to
the square of the distance between them?
A. Coulomb’s first law
B. Coulomb’s second law
C. Coulomb’s third law
D. Coulomb’s law or law of
electrostatics
ANSWER: D
109. What is the law whereby the force of
attraction and repulsion between poles is
inversely proportional to the square of the
distance between them?
A. Newton’s first law
B. Newton’s second law
C. Norton’s law
D. Coulomb’s second law
ANSWER: D
110. Is usually used to detect the presence
of electric charge.
A. experimental charge
B. unit charge
C. dipole
D. test charge
ANSWER: D
111. Test charge has a charge of
A. 0 Coulomb
B. +1 Coulomb
C. -1 Coulomb
D. Infinity
ANSWER: B
112. Three charges of +5 C, -6 C and +7 C are
placed inside a sphere, what is the total
charge of the sphere?
A. +5 Coulomb
B. -6 Coulomb
C. -7 Coulomb
D. +6 Coulomb
ANSWER: D
113. A combination of two charges, with
equal charge magnitude but opposite signs.
A. magnetic dipole
B. static dipole
C. dynamic dipole
D. electric dipole
ASNWER: D
114. The space outside or surrounding an
electric charge where it has a force of
attraction or repulsion.
A. Electric field
B. Magnetic field
C. Electromagnetic field
D. Electric flux
ANSWER: A
115. Refers to a force of field that exists
between ions where they either repel or
attract each other.
A. Resisting field
B. Potential field
C. Dielectric
D. Electromotive
ANSWER: D
116. The imaginary lines representing the
electric field.
A. Electric field
B. Electric flux
C. Electric flux density
D. Electric lines of force
ANSWER: D
117. What is true in visualizing electric field
lines of force from a charge body?
A. Field lines are continuous curve and
they never intersect.
B. The spacing between these lines
increases as they get far from the
charged body.
C. The number of field lines is directly
proportional to the magnitude of
the electric field.
D. All of the above.
ANSWER: D
118. What do you call the total number of
electric lines of force in an electric field?
A. Electric field
B. Electric flux
C. Electric flux density
D. Electric lines of force
ANSWER: B
119. The number of lines per unit area in a
plane perpendicular to the electric lines of
force.
A. Electric field
B. Electric flux
C. Electric flux density
D. Electric lines of force
ANSWER: C
120. Electric lines of force leave and enter
the charge surface at what angle?
A. 15°
B. 30°
C. 45°
D. 90°
ANSWER: D
121. Find the dielectric constant of air.
A. approximately 1
B. approximately 0
C. approximately 2
D. approximately 4
ANSWER: A
122. Electric field intensity is measured in
terms of
A. Volts/meter
B. Newtons/meter
C. Watts/meter
D. Amperes/meter
ANSWER: A
123. Electric field intensity is
A. a scalar quantity
B. a vector quantity
C. an absolute value
D. a relative value
ANSWER: B
124. Electric flux is a/an ________ quantity.
A. scalar
B. vector
C. absolute
D. relative
ANSWER: A
125. Electric flux density is a/an ________
quantity.
A. scalar
B. vector
C. absolute
D. relative
ANSWER: B
126. Three charges of +5 C, -6 C, and +7 C
are inside a sphere, what is the total
electric flux passing through the surface
of the sphere?
A. 5 Coulombs
B. 6 Coulombs
C. 7 Coulombs
D. 8 Coulombs
ANSWER: B
127. An electric charge produces a total electric
field of 6 Coulombs, calculate the electric
flux density in an area of one square
meter (1m2).
A. 1 C/m2
B. 2 C/m2
C. 4 C/m2
D. 6 C/m2
ANSWER: D
128. The measure of density of the electric
charge
A. Electric gradient
B. Electric current
C. Electric charge
D. Electric potential
ANSWER: D
129. The ability of the material to store
electrical potential energy under the
influence of an electric field.
A. capacity
B. permeability
C. permittivity
D. conductivity
ANSWER: C
130. The absolute permittivity of air or free
space.
A. 1/36π x 10-9 F/m
B. 36π x 10-9 F/m
C. 1/36π x 10-19 F/m
D. 36π x 10-19 F/m
ANSWER: A
131. The relative permittivity of air.
A. 0
B. 1
C. 1/36π x 10-9 F/m
D. 8.854 x 10-12 F/m
ANSWER: B
132. Calculate the permittivity of a material
with relative permittivity of 5.
A. 8.854 x 10-11 F/m
B. 4.42 x 10-11 F/m
C. 1/36π x 10-9 F/m
D. 8.854 x 10-12 F/m
ANSWER: B
133. What is the term used to express the
amount of electrical energy stored in an
electrostatic field?
A. Volts
B. Watts
C. Coulombs
D. Joules
ANSWER: D
134. How does permittivity affect electric
field intensity?
A. It causes the field intensity to
increase.
B. It causes the field intensity to
decrease.
C. It causes the field intensity to
fluctuate up and down.
D. It has no effect on field intensity.
ANSWER: B
135. Relative permittivity is also known as
A. dielectric constant
B. dielectric strength
C. isolation strength
D. permeability
ANSWER: A
136. Most materials’ relative permittivity lies
between
A. 0.01 – 1
B. 1 – 10
C. 10 – 50
D. 50 – 100
ANSWER: B
137. Charge body at rest is said to exhibit
electric field, which interacts with other
bodies. The study of this phenomena is
known as
A. electricity
B. electrostatics
C. electromagnetism
D. field interactions
ANSWER: B
138. The basic law for interaction of charged
bodies at rest.
A. Charged law
B. Gauss’ law
C. Faraday’s law
D. Coulomb’s law
ANSWER: D
139. The force between the two electrically
charged body is called
A. electromotive force
B. electrostatic force
C. electromagnetic force
D. magnetic force
ANSWER: B
140. The force between two electrically
charged body is
A. directly proportional to the charge
B. inversely proportional to the charge
C. not affected by the charge
D. universally constant
ANSWER: A
141. In 1784, who demonstrated that the force
between charges is inversely related to
the square of the distance between them?
A. Maxwell
B. Gauss
C. Tesla
D. Coulomb
ANSWER: D
142. Determine the force in Newton between
4μC charges separated by 0.1 meter in
air.
A. 1.44 N
B. 14.4 N
C. 144 N
D. 1440 N
ANSWER: B
143. What will happen when two opposite
charges get closer?
A. repels less
B. attracts less
C. repels more
D. attracts more
ANSWER: D
144. The value of k in Coulomb’s electrostatic
force equation ( F = kQ1Q2/r2 ) is
oftentimes expressed as 1/4πεο. What is
εο?
A. absolute permeability
B. absolute permittivity
C. relative permeability
D. relative permittivity
ANSWER: B
145. The measure of electric field strength per
unit length is known as electric field
intensity or simply electric intensity. What
is its unit?
A. Volt/meter (V/m)
B. Joules/Coulomb-meter (J/Cm)
C. Newton/Coulomb (N/C)
D. All of the above
ANSWER: D
146. Calculate the electric field intensity 10cm
from a charge Q=5nC.
A. 450 N/C
B. 900 N/C
C. 4.5 x 103 N/C
D. 9.0 x 103 N/C
ANSWER: C
147. Determine the magnitude of the electric
field inside a sphere that encloses a net
charge of 2μC.
A. 0 (zero)
B. 9 x 107 N/C
C. 1.8 x 108 N/C
D. infinite
ANSWER: A
148. Calculate the total electric field at the
surface of a sphere of radius r=1cm, and
enclosing a net charge of 2μC.
A. 0 (zero)
B. 9 x 107 N/C
C. 1.8 x 108 N/C
D. infinite
ANSWER: C
149. A 2nC point charge will produce what
potential at 2m away?
A. 4.0 Volts
B. 6.0 Volts
C. 7.5 Volts
D. 9.0 Volts
ANSWER: D
150. A charged body in free space produces
10-V potential at a distance 25cn away.
What will be the potential at 50cm away?
A. 5.0 Volts
B. 7.5 Volts
C. 10.0 Volts
D. 15.0 Volts
ANSWER: A
151. What do you call the phenomenon
whereby substance attracts pieces of iron?
A. Permeability
B. Magnetism
C. Naturalism
D. Electromagnetism
ANSWER: B
152. The condition in which a substance
attracts pieces of iron is known as
A. Electromagnetism
B. Electrolysis
C. Magnetism
D. Magnetic Induction
ANSWER: C
153. A substance that attracts pieces iron is
known as
A. magnet
B. conductor
C. ferrite
D. superconductor
ANSWER: A
154. A natural magnet
A. loadstone
B. carbon
C. lodestone
D. magnesium
ANSWER: C
155. Group of magnetically aligned atoms.
A. Lattice
B. Crystal
C. Domain
D. Range
ANSWER: C
156. In a magnet, what do you call the point in
which the magnetic lines of force is
maximum?
A. maximum pole
B. intensified pole
C. unit pole
D. magnetic pole
ANSWER: D
157. Which of the following refers to a
characteristic of a magnetic line of force?
A. Travels from south to north
through the surrounding medium of
a bar magnet
B. Travels back and forth between the
north and south pole of a bar
magnet
C. Travels from north to south
through the surrounding medium of
a bar magnet
D. Stay stationary between the north
and the south of a bar magnet
ANSWER: C
158. Is believed to be the pole where the
magnetic lines of force are originating.
A. North Pole
B. South Pole
C. Unit Pole
D. Universal Pole
ANSWER: A
159. What do you call a pole that when place in
air with a similar and equal pole will cause
a force of repulsion of 1/4πμο Newtons?
A. South Pole
B. Unit pole
C. Convergence pole
D. Universal Pole
ANSWER: B
160. In a magnet, the straight line passing
through the two poles is called
A. real axis
B. imaginary axis
C. Cartesian axis
D. magnetic axis
ANSWER: D
161. The phenomenon in which a substance
becomes a magnet when placed near a
magnet.
A. magnetic transfer
B. magnetic induction
C. electromagnetism
D. magnetism
ANSWER: B
162. A force which causes a substance to
become a magnet.
A. magnetizing force
B. magnetomotive
C. creative force
D. electromagnetic force
ANSWER: A
163. What do you call the quantity of
magnetism retained by a magnetic
material after the withdrawal of a
magnetizing force?
A. Left over magnetism
B. Coercivity
C. Hysteresis
D. Residual magnetism
ANSWER: D
164. Is the property of magnetic materials,
which retain magnetism after the
withdrawal of magnetizing force.
A. retentivity
B. permeability
C. reluctivity
D. susceptability
ANSWER: A
165. A substance having high retentivity is best
suited in making
A. an electromagnet
B. a temporary magnet
C. a permanent magnet
D. two pole magnet
ANSWER: C
166. Which of the materials below that can be
easily magnetized?
A. soft magnetic materials
B. hard magnetic materials
C. low conductive materials
D. high conductive materials
ANSWER: A
167. Materials that can be easily magnetized in
both directions
A. soft magnetic materials
B. hard magnetic materials
C. diamagnetic
D. paramagnetic
ANSWER: A
168. Ability of a material to conduct magnetic
flux through it refers to
A. permittivity
B. permeability
C. reluctivity
D. conductivity
ANSWER: B
169. The ability to concentrate magnetic lines
of force.
A. retentivity
B. permeability
C. susceptability
D. reluctivity
ANSWER: B
170. The permeability of free space.
A. 4π x 10-7 H/m
B. 12.56 x 10-7 F/m
C. 8.854 x 10-7 H/m
D. 8.854 x 10-12 F/m
ANSWER: A
171. The ratio of material permeability to the
permeability of air or vacuum.
A. relative conductivity
B. relative permeability
C. inverse permeability
D. inverse permittivity
ANSWER: B
172. What is the relative permeability of air?
A. 0
B. 1
C. 4π x 10-7 H/m
D. 8.854 x 10-12 F/m
ANSWER: B
173. Materials with permeability slightly less
than that of free space.
A. diamagnetic
B. paramagnetic
C. ferromagnetic
D. antimagnetic
ANSWER: A
174. Materials with permeability slightly
greater than that of free space.
A. diamagnetic
B. paramagnetic
C. ferromagnetic
D. antimagnetic
ANSWER: B
175. What do you call materials, which possess
very high permeabilities?
A. diamagnetic
B. paramagnetic
C. ferromagnetic
D. antimagnetic
ANSWER: C
176. What is the relative permeability of
paramagnetic substance?
A. slightly greater than 1
B. very much greater than 1
C. slightly less than 1
D. very much smaller than 1
ANSWER: A
177. Permeability of a material means:
A. The ability of the material to
conduct electric field
B. The conductivity of the material for
electromagnetic field
C. The ability of the material to hold
magnetic flux
D. The conductivity of the material for
magnetic lines of force
ANSWER: D
178. Nonmetallic materials that has
ferromagnetic properties.
A. termites
B. ferrites
C. ferrous
D. loadstone
ANSWER: B
179. Cores of magnetic equipment use
magnetic material which has
A. very low permeability
B. moderate permeability
C. low permeability
D. high permeability
ANSWER: D
180. Hydrogen is an example of a _________
material.
A. diamagnetic
B. ferromagnetic
C. paramagnetic
D. magnetic
ANSWER: A
181. Cobalt is an example of a _________
material.
A. diamagnetic
B. ferromagnetic
C. paramagnetic
D. magnetic
ANSWER: B
182. The space outside a magnet where its
poles has a force of attraction or repulsion
on another magnetic pole.
A. magnetic field
B. magnetic flux
C. magnetic flux density
D. magnetic lines of force
ANSWER: A
183. The imaginary lines representing the
magnetic field.
A. magnetic field
B. magnetic flux
C. magnetic flux density
D. magnetic lines of force
ANSWER: D
184. What do you call the total number of
magnetic lines of force in a magnetic
field?
A. magnetic field
B. magnetic flux
C. magnetic flux density
D. magnetic lines of force
ANSWER: B
185. The number of lines per unit area in a
plane perpendicular to the magnetic lines
of force.
A. magnetic field
B. magnetic flux
C. magnetic flux density
D. magnetic lines of force
ANSWER: C
186. The direction of field lines outside a
magnet is
A. from north to south pole
B. from south to north pole
C. either from north to south or south
to north pole
D. dependent on the magnet’s
orientation with respect to the
earth’s magnetic pole
ANSWER: C
187. The entire group of magnetic field lines
flowing outward from the north pole of a
magnet.
A. magnetic field
B. magnetic flux density
C. magnetic flux
D. electromagnetic field
ANSWER: C
188. Magnetic lines of force are called
A. magnetic field
B. magnetic flux density
C. magnetic flux
D. electromagnetic field
ANSWER: C
189. What is the unit of magnetic flux in SI
system?
A. Weber
B. Maxwell
C. Tesla
D. Gauss
ANSWER: A
190. The unit of magnetic flux density in SI:
A. Gauss
B. Weber
C. Maxwell
D. Tesla
ANSWER: D
191. A magnetic flux of 25,000 maxwell in an
area of 5 sqcm. results in flux density of
A. 5,000 Gauss (G)
B. 125,000 G
C. 5,000 Tesla (T)
D. 125,000 T
ANSWER: A
192. Calculate the flux density in Gauss (G)
having a flux of 12,000 Mx through a
perpendicular area of 6cm.
A. 200 G
B. 2,000 G
C. 7,200 G
D. 72,000 G
ANSWER: B
193. What does a gaussmeter measure?
A. flux
B. magnetic field
C. magnetic flux density
D. mmf
ANSWER: C
194. The capacity of a substance to become
magnetized. This is expressed as a ratio
between the magnetization produced in a
substance to the magnetizing force
producing it.
A. magnetic conductivity
B. magnetic susceptibility
C. magnetic resistivity
D. magnetic reluctivity
ANSWER: B
195. The typical saturation flux density for
most magnetic materials.
A. 0.1 Wb/m2
B. 2 Wb/m2
C. 10 Wb/m2
D. 20 Wb/m2
ANSWER: B
196. The force between two magnetic poles is
_________ permeability of the medium.
A. directly proportional to the
B. inversely proportional to the
C. not dependent of the
D. exponentially proportional to the
ANSWER: B
197. If the distance between two magnetic
poles is halve, the force between them
A. decreases two times
B. decreases four times
C. increases two times
D. increases four times
ANSWER: D
198. A force of 20 N is acting on a 10 Wb
magnetic pole, calculate the intensity of
the magnetic field?
A. 0.5 N/Wb
B. 2 N/Wb
C. 10 N/Wb
D. 20 N/Wb
ANSWER: B
199. Unit of permeability
A. Henry/meter (H/m)
B. Farad/meter (F/m)
C. Henry-meter (H-m)
D. Farad-meter (F-m)
ANSWER: A
200. The unit of permittivity
A. Henry/meter (H/m)
B. Farad/meter (F/m)
C. Henry-meter (H-m)
D. Farad-meter (F-m)
ANSWER: B
201. Magnetic intensity is
A. a vector quantity
B. a scalar quantity
C. an imaginary quantity
D. either a vector or scalar
ANSWER: A
202. The Gauss is a unit of
A. permeability
B. electromagnetic force
C. magnetic force
D. magnetic flux density
ANSWER: D
203. What is the unit of flux in cgs?
A. Ampere-turn (At)
B. Coulomb/sec. (C/s)
C. Maxwell (Mx)
D. Gauss
ANSWER: C
204. One Weber is equivalent to
A. 108 Maxwells
B. 106 Maxwells
C. 104 Maxwells
D. 102 Maxwells
ANSWER: A
205. The equivalent of 1 x 109 Maxwells is
A. 1 Weber
B. 10 Weber
C. 100 Weber
D. 1,000 Weber
ANSWER: B
206. A magnetic flux of 500,000,000 lines is
equivalent to
A. 5 x 108 Maxwells
B. 5 Weber
C. 500 x 106 MAxwells
D. all of the above
ANSWER: D
207. The unit of flux density in mks
A. Gauss
B. Weber/m2
C. Maxwell
D. Tesla
ANSWER: B
208. What do you call the force that sets up or
tends to set up magnetic flux in a
magnetic circuit?
A. electromotive force
B. potential difference
C. magnetomotive force
D. dynamic force
ANSWER: C
209. Voltage in electrical circuits is analogous
to _________ in magnetic circuits.
A. Ampere-turn
B. Magnetomotive force
C. Magnetizing force
D. Flux
ANSWER: B
210. Electrical current is analogous to
_________ in magnetic circuits.
A. Ampere-turn
B. Magnetomotive force
C. Magnetizing force
D. Flux
ANSWER: D
211. __________ capability is analogous to
permeance.
A. Admittance
B. Conductance
C. Reluctance
D. Resistance
ANSWER: B
212. Resistance in electrical circuits is
analogous to _________ in magnetic
circuits.
A. Conductance
B. Permeance
C. Elastance
D. reluctance
ANSWER: D
213. The property of a material which opposes
the creation of magnetic flux.
A. elastance
B. permeance
C. susceptance
D. reluctance
ANSWER: D
214. The reciprocal of reluctance
A. conductance
B. permeance
C. elastance
D. capacitance
ANSWER: B
215. Permeance is analogous to
A. conductance
B. resistance
C. impedance
D. elastance
ANSWER: A
216. Is the reciprocal of reluctance and implies
the readiness of a material to develop
magnetic flux.
A. elastance
B. permeance
C. susceptance
D. conductance
ANSWER: B
217. Magnetic circuit property that permits
flux.
A. elastance
B. permeance
C. susceptance
D. conductance
ANSWER: B
218. It is easier to establish flux line in soft
iron than it is to establish them in air, this
is because iron has a lower
A. Permeance
B. Inductance
C. elastance
D. reluctance
ANSWER: D
219. The Oersted (Oe) is the same as
A. 1 Gb/cm
B. 1 Gb/m
C. 10 Gb/cm
D. 10 Gb/cm
ANSWER: A
220. The unit of reluctance
A. Gilbert
B. Tesla
C. At/Wb
D. Gauss
ANSWER: C
221. It is the specific reluctance of a material.
A. resistivity
B. retentivity
C. reluctivity
D. permeability
ANSWER: C
222. At/m is a unit of
A. magnetic field
B. reluctance
C. magnetizing force
D. magnetic power
ANSWER: C
223. Magnetomotive force has a unit of
A. Volt (V)
B. Watt (W)
C. Joule (J)
D. Ampere-turn (At)
ANSWER: D
224. The cgs unit of magnetomotive force
A. Volt
B. Weber
C. Gilbert
D. Ampere-turn
ANSWER: C
225. One Gilbert is equal to
A. 0.0796 At
B. 0.796 At
C. 7.96 At
D. 79.6 At
ANSWER: B
226. One Ampere-turn (At) is equivalent to
A. 0.126 Gilbert
B. 1.260 Gilberts
C. 12.60 Gilberts
D. 126 Gilberts
ANSWER: B
227. The current needed for a coil of 200 turns
to provide a 400 ampere turn magnetizing
force is
A. 2 A
B. 4 A
C. 6 A
D. 8 A
ANSWER: A
228. Determine the ampere-turns when a 10 V
battery is connected across a solenoid
having 100 turns and a resistance of 5 Ω.
A. 50 At
B. 200 At
C. 100 At
D. 1,000 At
ANSWER: B
229. What is residual magnetism?
A. The external magnetic field when
the current is flowing through the
exciting coil.
B. The flux density, which exist in the
iron core when the magnetic field
intensity is reduced to zero.
C. The flux density, which exist in the
iron core when the magnetic field
intensity is at its maximum value.
D. The flux density when the magnetic
core is saturated.
ANSWER: B
230. When you demagnetize property by
applying an AC field and then gradually
reduced it to zero, it is called
A. damping
B. decaying
C. degaussing
D. gaussing
ANSWER: C
231. In a magnetic circuit, a flux that drifts
away from its intended path is called
A. lost flux
B. linked flux
C. drift flux
D. leakage flux
ANSWER: D
232. Is the quantity of magnetizing force
needed to counter balance the residual
magnetism of a magnetic material.
A. hysteresis
B. degaussing
C. retentivity
D. coercivity
ANSWER: D
233. What do you call the loss of electrical
energy in counter balancing the residual
magnetism in each cycle?
A. hysteresis
B. magnetomotive
C. leakage
D. coercivity
ANSWER: D
234. The amount of magnetic field needed to
remove residual magnetism from a
transformer core during each half cycle is
called the
A. coercive force
B. residual field
C. hysteresis field
D. demagnetizing force
ANSWER: A
235. If a wire coil has 100 turns and carries 1.3
A of current, calculate the magnetomotive
force in Gilbert.
A. 163.3
B. 16.33
C. 1.633
D. 0.1633
ANSWER: A
236. An advantage of an electromagnet over a
permanent magnet
A. An electromagnet can be
demagnetized
B. An electromagnet is simpler
C. An electromagnet is cheaper
D. An electromagnet can be switched
ON and OFF
ANSWER: D
237. Electromagnet whose core is in the form
of a close magnetic ring
A. solenoid
B. relay
C. toroid
D. circular
ANSWER: C
238. Magnetic flux can always be attributed to
A. static charged particles
B. motion of charge particles
C. static electric field
D. every applied potential
ANSWER: B
239. What is a magnetic field?
A. A force set up when current flows
through a conductor.
B. A force set up when a charged
body is at static.
C. The space between two electrically
charged particles.
D. The space around a conductor.
ANSWER: A
240. Which of the following determines the
strength of a magnetic field around a
conductor?
A. amount of current
B. diameter of the conductor
C. length of the conductor
D. amount of voltage
ANSWER: A
241. The magnetic flux around a straight,
current carrying wire, is stronger
A. near the edge
B. near the wire
C. at the center
D. at both edge
ANSWER: B
242. In what direction is the magnetic field
about a conductor when current is
flowing?
A. In a direction determined by the
left-hand rule.
B. Always in a clock wise direction.
C. Always in a counter clockwise
direction.
D. In a direction determined by the
right-hand screw rule.
ANSWER: A
243. If the electrical current carried by each of
the two long parallel wire is doubled, and
their separation is also doubled, the force
between them
A. also doubles
B. increases by a factor of four
C. decreases by a factor of four
D. decreases by a factor of two
ANSWER: A
244. Reversing the flow of current in a circuit
A. reverses the magnetic polarity
B. increase the magnetic field
intensity
C. decreases the magnetic intensity
D. enhances hysteresis
ANSWER: A
245. Is used to maintain strength of magnetic
field.
A. storer
B. energizer
C. gausser
D. keeper
ANSWER: D
246. What law that describes the force of
attraction or repulsion between two
magnetic poles is directly proportional to
their strengths?
A. Coulomb’s first law
B. Coulomb’s second law
C. Ampere’s law
D. Gauss’ law
ANSWER: A
247. What is the law whereby the force of
attraction or repulsion between poles is
inversely proportional to the square of the
distance between them?
A. Coulomb’s first law
B. Coulomb’s second law
C. Coulomb’s third law
D. Coulomb’s law
ANSWER: B
248. The physical motion resulting from the
forces of magnetic fields.
A. motor action
B. linear motion
C. rectilinear motion
D. generator action
ANSWER: A
249. What law in electronics where an induced
current will be in such a direction that its
own magnetic field will oppose the
magnetic field that produces the same?
A. Electromagnetic law
B. Nortons law
C. Lenz law
D. Maxwell law
ANSWER: C
250. A changing magnetic field
A. produces an electric field
B. induces potential
C. produces a fluctuating electric field
D. produces a steady electric field
ANSWER: B
251. The emf induced in a coil due to the
change of its flux linked with it is called
A. mutual emf
B. crossfire induced emf
C. self induced emf
D. virtually induced emf
ANSWER: C
252. If two coils are close enough together for
their magnetic fields to interact, a change
in current in one will induce a
corresponding voltage in the other, This
condition is known as
A. self-inductance
B. mutual inductance
C. crossfire inductance
D. linked inductance
ANSWER: B
253. If the magnetic flux through a coil
changes, the induced EMF acts in such a
direction as to
A. oppose that change
B. magnify that change
C. augment that change
D. amplify that change
ANSWER: A
254. When a conductor is moved through a
magnetic field a voltage is always
induced. The amount of voltage is always
proportional to
A. the diameter of the conductor used
B. the length of the conductor
C. the distance of the conductor from
the field
D. the rate at which the conductor is
moved
ANSWER: D
255. The term of energy that is stored in an
electromagnetic or electrostatic field
A. kinetic energy
B. static energy
C. dynamic energy
D. potential energy
ANSWER: D
256. What is meant by back EMF?
A. A voltage that is applied in the
reverse direction.
B. An EMF that is dude to the fly
wheel effect.
C. An EMF that is generated from the
back of an electromagnet.
D. A voltage that opposes the applied
EMF.
ANSWER: D
257. When current in a conductor increases,
Lenz’ law states that the self-induced
potential will
A. produce current opposite to the
increasing current
B. tend to produce more magnetic
field
C. tend to augment the increase in
current
D. produce current with the same
direction to the increasing current
ANSWER: A
258. If a magnetic flux occurs across 100 turns
at a rate of 2 Wb/sec. What is the induced
voltage as per Faraday’s law?
A. 100 V
B. 400 V
C. 200 V
D. 800 V
ANSWER: C
259. The circuit element that is used represent
the energy stored in a magnetic field.
A. resistance
B. capacitance
C. inductance
D. elastance
ANSWER: C
260. Which of the given below can produce the
most induced voltage?
A. 1 A dc
B. 1 A, 60 Hz
C. 50 A dc
D. 1 A, 400 Hz
ANSWER: D
261. In all cases of electromagnetic induction,
the current set-up by an induced voltage
tends to create flux whose direction
opposes any change in the existing flux.
This law is called
A. Ampere’s law
B. Lenz’ law
C. Coulomb’s law
D. Faraday’s law
ANSWER: B
262. In electromagnetism, what law that
determines the polarity of an induced
voltage?
A. Ampere’s law
B. Lenz’ law
C. Coulomb’s law
D. Faraday’s law
ANSWER: B
263. In electromagnetism, what law that
determines the amount of induced
voltage?
A. Ampere’s law
B. Lenz’ law
C. Coulomb’s law
D. Faraday’s law
ANSWER: D
264. Electromotive force (emf) is induced
whenever a conductor cuts magnetic flux
A. Faraday’s first law
B. Faraday’s second law
C. Coulomb’s first law
D. Coulomb’s second law
ANSWER: A
265. The magnitude of electromotive force
(emf) that is induced when a conductor
cuts magnetic flux is directly proportional
to its rate.
A. Faraday’s first law
B. Faraday’s second law
C. Coulomb’s first law
D. Coulomb’s second law
ANSWER: B
266. The effect that describes the ability of a
mechanically stressed ferromagnetic wire
to recognize rapid switching of
magnetization when subjected to a DC
magnetic field.
A. Wiegand effect
B. Wertheim effect
C. Wiedemann effect
D. Wall effect
ANSWER: A
267. The concept whereby a small voltage is
generated by a conductor with current in
an external magnetic field is known as
A. Wiegand effect
B. Hall effect
C. Wiedemann effect
D. Wall effect
ANSWER: B
268. _________ is called the magnetic field.
A. The force that drives current
through a resistor
B. Current flow through space around
a permanent magnet
C. The force between the plates of
charged capacitor
D. A force set up when current flow
through a conductor
ANSWER: D
269. The natural magnet refers to
A. steel
B. soft iron
C. magnesia
D. loadstone (lodestone)
ANSWER: D
270. The force between two magnetic poles in
relation to their pole strength is
________.
A. not related
B. inversely proportional
C. directly proportional
D. independent
ANSWER: C
TEST2.
1. The total resistance of a two similar wire conductors connected in parallel is ________.
A. resistance of one wire multiplied by 4
B. same resistance of one wire
C. one half the resistance of one wire
D. double the resistance of one wire
ANSWER: C 2. What is the value of a resistor with colors from
left: Orange, Blue, Gold, and Silver?
A. 34 ohms ± 10%
B. 3.6 ohms ± 10%
C. 3.4 ohms ± 10%
D. 36 ohms ± 10%
ANSWER: B
3. Determine the value of a resistor with colors from left to right; Brown, Green, Gold, and Silver.
A. 1.5 ohms ± 10%
B. 15 ohms ± 10%
C. 1.5 ohms ± 20%
D. 15 ohms ± 20%
ANSWER: A
4. Resistors with high value usually have lower wattage ratings because of _________.
A. varying current
B. lower current
C. bigger size
D. high current
ANSWER: B
5. Smaller resistors usually have ________ resistance value.
A. small
B. high
C. low
D. very small
ANSWER: B
6. When resistors are connected in series, what happens?
A. The effective resistance is decreased
B. Nothing
C. The tolerance is decreased
D. The effective resistance is increased
ANSWER: D
7. A 33 kilo ohms resistor is connected in series with a parallel combination made up of a 56 kilo
ohm resistor and a 7.8 kilo ohm resistor. What is the total combined resistance of these three resistors?
A. 63769 ohms
B. 49069 ohms
C. 95800 ohms
D. 39067 ohms
ANSWER: D
8. If you need a 1.25 kΩ resistance and you only have resistors of 5 kΩ, how many of these available resistors you should connect in parallel to get a 1.25 kΩ value?
A. 2
B. 3
C. 4
D. 5
ANSWER: C
9. Insulating elements or materials has a capability of
A. allowing electric current to flow
B. supporting charge flow
C. preventing short circuit between
conducting wires
D. making electrical circuits to be
completed ANSWER: C
10. _________ is used to store electrical energy in an electrostatic field?
A. A transformer
B. A battery
C. A capacitor
D. An inductor
ANSWER: C
11. What factors determine the capacitance of a capacitor?
A. Area of the plates, amount of charge on
the plates and the dielectric constant of the material between the plates
B. Area of the plates, voltage on the plates
and the distance between the plates
C. Area of the plates, distance between
the plates, and the dielectric constant of the material between the plates
D. Area of the plates, voltage on the plates
and dielectric constant of the material between the plates
ANSWER: C
12. Factors that determine the capacitance of a capacitor.
A. area of the plate; directly proportional
B. distance between plate; inversely
proportional
C. dielectric constant; directly proportional
D. all of these
ANSWER: D
13. An electronic/electrical component/device used to store electrical energy.
A. Capacitor
B. Inductor
C. Resistor
D. lightning arrester
ANSWER: A
14. Which of the following describes the action of a capacitor?
A. Converts ac into dc
B. Stores electrical energy
C. Opposes change in current flow
D. Creates a dc resistance
ANSWER: B
15. A parallel plate capacitor has the following values: k=81; d=0.025 inches; A=6 square inches. What is the capacitance of the capacitor?
A. 4.372 picofarad
B. 43.72 picofarad
C. 4372 picofarad
D. 437.2 picofarad
ANSWER: C
16. Five picofarad is equivalent to ________.
A. 5 x 10 to the -12th
B. 50 x 10 to the -12th
C. 5 x 10 to the -10th
D. 500 x 10 to the -10th
ANSWER: A
17. If two micro-farad capacitors are connected in series, what will be the total effective capacitance?
A. 0.125 microfarad
B. 0.0624 microfarad
C. 2.5 microfarad
D. 0.50 microfarad
ANSWER: A
18. A 20 μF capacitor is charged by a 12-V battery. What is the stored energy at the capacitor?
A. 2.88 x 10-3 J
B. 1.07 x 10-3 J
C. 1.44 x 10-3 J
D. 2.88 x 10-2 J
ANSWER: C
19. Which of the following characterizes inductance?
A. Tends to oppose dc
B. Tends to oppose changes in voltage
C. Tends to oppose changes in current
D. Opposes all frequencies equally
ANSWER: C
20. A coil of wire wound, with or without a magnetic core designed to have a higher self-inductance than a straight wire.
A. Inductor
B. Solenoid
C. Toroid
D. Inductive relay
ANSWER: A
21. With the same voltage applied, which of the following allows more current?
A. 25 ohms
B. 250 ohms
C. 0.25 ohms
D. 2.5 ohms
ANSWER: C
22. In electrical circuits, current is known as the flow of charged carriers, such as electrons. When can this happen?
A. when an electrical force (called emf) is
applied
B. when material used allows electrons to
flow
C. when there is circuit continuity
D. all of the above
ANSWER: D
23. What utilizes electrical energy in electrical circuits?
A. supply emf
B. load
C. the conducting wires
D. all of the above
ANSWER: B
24. An electronic device draws 300 watts from its 24-volt power source. Find effective resistance.
A. 1.92 ohms
B. 19.20 ohms
C. 1.25 ohms
D. 12.50 ohms
ANSWER: A
25. A 50Ω resistor is connected in series with a 150C resistor and to a supply voltage of 20V. What is the current through the 50Ω resistor?
A. 0.01 A
B. 0.1 A
C. 1.0 A
D. 10 A
ANSWER: B
26. Two resistors, 10Ω and 100Ω are connected in parallel, approximately, aht is the total resistance?
A. 10Ω
B. 50Ω
C. 90Ω
D. 100Ω
ANSWER: A
27. A shunt resistor is used to limit the load current to 0.5 A, if the load resistance is 100Ω and the original current is 1amp, what should be the value of the shunt resistance?
A. 25Ω
B. 50Ω
C. 75Ω
D. 100Ω
ANSWER: D
28. How many 1kΩ resistors to be connected in parallel are needed in order to get 100Ω?
A. 2
B. 5
C. 10
D. 20
ANSWER: C
29. Two resistors, R1=100Ω and R2=200Ω are connected in series, if the voltage across R2 is 20V, what is the voltage across R1?
A. 5 V
B. 10 V
C. 15 V
D. 20 V
ANSWER: B
30. Two resistors, R1=100Ω and R2=200Ω are connected in parallel. If the current through R1 is 1 A, what would be the current on R2?
A. 0.125 A
B. 0.25 A
C. 0.35 A
D. 0.50 A
ANSWER: D
31. A 6A current source drives a load consisting a parallel combination of R1 = 50Ω and R2 = 25Ω. Determine the current I1 through R1.
A. 1 amp
B. 2 amps
C. 3 amps
D. 4 amps
ANSWER: B
32. A constant voltage source Vs = 60 is delivering a power to a series combination of R1 = 100Ω, R2 = 200Ω and R3 = 300Ω. Calculate the voltage drop across R2.
A. 10 V
B. 20 V
C. 30 V
D. 40 V
ANSWER: B
33. If 12 V are applied to a circuit that consumes 78 W, what is the current flow through the circuit?
A. 6.5 A
B. 936 A
C. 0.15 A
D. 9.36 A
ANSWER: A
34. Find the current that flows through the filament of a 400 watts flat iron connected to a 220 Volt power line.
A. 50 mA
B. 5 A
C. 5 mA
D. 500 mA
ANSWER: D
35. An electrical device has a resistance of 10Ω and is supplied with a 5 ampere constant current source. If the deice is rated 100 Vdc, determine its power consumed.
A. 250 W
B. 450 W
C. 750 W
D. 1000 W
ANSWER: A
36. The power dissipated by a 10 Ω load resistor with a current rating of 5 amperes is _________ if supplied with a 20 volt dc potential.
A. 40 W
B. 80 W
C. 160W
D. 250 W
ANSWER: A
37. The power in a circuit consisting of two equal resistors in series is known to be 10 watts. If the two resistors are connected in parallel, what would be the circuit power dissipation?
A. 2.5 watts
B. 5 watts
C. 20 watts
D. 40 watts
ANSWER: D
38. How many nodes are needed to completely analyze a circuit according to kirchhoff’s current law?
A. two
B. all nodes in the circuit
C. one less than the total number of nodes
in the circuit
D. one
ANSWER: C
39. Loop currents should be assumed to flow in which direction?
A. Straight
B. Either C or D arbitrarily selected
C. Counter-clockwise
D. Clockwise
ANSWER: B
40. What theorem we should use in solving electrical circuits with several voltage sources?
A. superposition
B. Norton
C. Thevenin
D. Kirchhoff
ANSWER: A
41. In a mesh, the algebraic sum of all voltages and voltage drops is equal to zero.
A. superposition theorem
B. Norton’s law
C. Kirchhoff’s first law
D. Kirchhoff’s second law
ANSWER: D
42. The sum of all currents entering a junction is equal to the sum of currents leaving away from that junction.
A. Kirchhoff’s first law
B. Kirchhoff’s second law
C. Norton’s theorem
D. Thevenin’s theorem
ANSWER: A
43. Theorem used to simplify complex circuits wherein, the simplified circuit contains an equivalent open circuit resistance and open circuit voltage.
A. Norton’s
B. Thevenin’s
C. Maxwell’s
D. Kirchhoff’s
ANSWER: B
44. Considered as the reverse of Thevenin’s theorem.
A. Maxwell
B. Superposition
C. Kirchhoff
D. Norton’s
ANSWER: D
45. A certain Thevenin equivalent circuit has parameters RTH = 10 Ω and VTH = 20 V. If this is converted to Norton’s equivalent circuit, RN and IN would be
A. 10Ω and 2A
B. 10Ω and 4A
C. 0.10 and 2A
D. 0.10 and 4A
ANSWER: A
46. RN and IN of a Norton’s equivalent circuit are known to be 100Ω and 10A, respectively. If a 400Ω load is connected, it will have a load current of
A. 1 A
B. 2 A
C. 3 A
D. 4 A
ANSWER: B
47. A chosen closed path of current flow in a network. In making this current path there should be no node nor elements that are passed more than once.
A. node
B. junction
C. mesh
D. loop
ANSWER: C
48. A set of circuit elements that forms a closed path in a network over which signal can circulate.
A. node
B. junction
C. mesh
D. loop
ANSWER: D
49. In a network, what do we call a reference point chosen such that more branches in a circuit met.
A. node
B. junction
C. ground
D. mesh
ANSWER: A
50. A common connection between circuit elements or conductors from different branches.
A. node
B. junction
C. ground
D. mesh
ANSWER: B
51. The return point in a circuit, where all voltage measurements are referred.
A. node
B. junction
C. ground
D. loop
ANSWER: C
52. Mesh analysis is best used together with what circuit law?
A. KVL
B. KCL
C. VDT
D. CDT
ANSWER: A
53. Nodal analysis is best used together with
A. KVL
B. KCL
C. VDT
D. CDT
ANSWER: B
54. Three 100Ω resistors are connected in a tee-form (T) network and is set up between a 100 V supply and a load resistor RL. If maximum power transfer is desired, what should be the resistance of the load resistor RL?
A. 50 Ω
B. 75 Ω
C. 125 Ω
D. 150 Ω
ANSWER: D
55. Theorem used in simplifying circuit analysis by considering the effect of supply voltages one at a time.
A. Thevenin’s theorem
B. Norton’s theorem
C. Superposition
D. KVL
ANSWER: C
56. Three resistors, R1 = 60 Ω, R2 = 80 Ω and R3 = 100 are connected in delta. If the network is to
be transformed into star, what would be the value of the resistor opposite of R2?
A. 25.0 Ω
B. 33.3 Ω
C. 45.0 Ω
D. 56.7 Ω
ANSWER: A
57. The description of two sine waves that are in step with each other going through their maximum and minimum points at the same time and in the same direction
A. phased sine wave
B. sine waves in phase
C. sine wave in coordination
D. stepped sine waves
ANSWER: B
58. Most ac-supplies are in the form of
A. sine-wave
B. square-wave
C. triangular-wave
D. rectangular-wave
ANSWER: A
59. Advantage(s) of ac over dc
A. economically produced
B. transmission of ac is more efficient
C. ac voltages can be easily changed
D. all of the above
ANSWER: D
60. An ac-voltage has an equation v = 240 sin120πt, its frequency is
A. 60 Hz
B. 90 Hz
C. 120 Hz
D. 240 Hz
ANSWER: A
61. When can an ac-voltage, v = 120sin120πt reach its first peak?
A. 4.167 μs
B. 8.334 μs
C. 4.167 ms
D. 8.334 ms
ANSWER: C
62. Calculate the period of an alternating current having an equation of I = 20sin120πt.
A. 4.167 ms
B. 8.33 ms
C. 16.67 ms
D. 33.33 ms
ANSWER: C
63. The time taken by an alternating voltage, v = 100sin240πt to reach 50V for the first time
A. 358 μs
B. 695 μs
C. 358 ms
D. 695 ms
ANSWER: D
64. An alternating voltage of sine-wave form has a maximum voltage of 311V. What is its value at 225°?
A. 110 V
B. 220 V
C. -220 V
D. -110 V
ANSWER: C
65. If an alternating voltage has a magnitude of 10 V at 30°, what is its maximum voltage?
A. 20 V
B. 30 V
C. 40 V
D. 50 V
ANSWER: A
66. What is the frequency of an alternating current, if it reaches 90° within 4.167 ms?
A. 20 Hz
B. 30 Hz
C. 50 HZ
D. 60 Hz
ANSWER: D
67. At what angle does an alternating voltage of cosine-waveform reaches its negative peak?
A. 45°
B. 90°
C. 135°
D. 180°
ANSWER: D
68. When comparing rms voltages and average voltages, which of the following statement is true, assuming sine waves?
A. Either the rms voltage or the average
voltage might be larger
B. The rms voltage is always greater than
the average voltage
C. There will always be a very large
difference between the rms voltage and the average voltage
D. The average voltage is always greater
than the rms voltage
ANSWER: B
69. What is the average voltage of an alternating voltage, v = 100sin120πt?
A. 31.8 V
B. 63.6 V
C. 70.71 V
D. 0 (zero) V
ANSWER: D
70. Determine the effective voltage of v = 100sin120πt.
A. 31.80 V
B. 35.35 V
C. 70.71 V
D. 90.00 V
ANSWER: D
71. What do you mean by root-mean-squared (rms) value?
A. it is the average value
B. it is the effective value
C. it is the value that causes the same
heating effect as a dc-voltage
D. B or C
ANSWER: D
72. The power dissipated across the resistance in an AC circuit
A. real power
B. reactive power
C. apparent power
D. true power
ANSWER: D
73. In AC circuit, resistors will dissipate what power?
A. reactive
B. passive
C. inductive
D. true
ANSWER: D
74. In an ac-circuit, if the voltage and current are in phase, the circuit is
A. resistive
B. reactive
C. capacitive
D. inductive
ANSWER: A
75. If the current in an ac-circuit leads the voltage by 90°, the circuit is
A. resistive
B. capacitive
C. inductive
D. purely inductive
ANSWER: B
76. In a purely inductive circuit the current
A. leads the voltage by 45°
B. leads the voltage by 90°
C. lags the voltage by 90°
D. lags the voltage by 45°
ANSWER: C
77. If the current and voltage in an ac-circuit has a phase difference, it would mean the load is
A. resistive
B. capacitive
C. inductive
D. reactive
ANSWER: D
78. A resistive and a capacitive load of equal magnitude is connected in series, determine the phase difference between the voltage and the current.
A. current leads the voltage by 45°
B. current lags the voltage by 45°
C. current leads the voltage by 90°
D. current lags the voltage by 90°
ANSWER: A
79. The reactance of a 25 mH coil at 500 Hz is which of the following?
A. 785 ohms
B. 785,000 ohms
C. 13 ohms
D. 0.0013 ohms
ANSWER: A
80. The impedance in the study of electronics is represented by resistance and ________.
A. inductance and capacitance
B. inductance
C. reactance
D. capacitance
ANSWER: C
81. A series circuit consists of an 80 mH inductor and a 150μF capacitor. Calculate the total reactance if it is connected to a 220-volt 60-cycle source.
A. 12.5 Ω inductive
B. 12.5 Ω capacitive
C. 47.8 Ω inductive
D. 47.8 Ω capacitive
ANSWER: A
82. Ignoring any inductive effects, what is the impedance of RC series capacitor made up of a 56 kilo ohms resistor and a 0.33 μF capacitor at a signal frequency of 450 Hz?
A. 66,730 ohms
B. 57,019 ohms
C. 45,270 ohms
D. 10,730 ohms
ANSWER: B
83. A 220-volt, 60-Hz source is driving a series RL circuit. Determine the current in the circuit if R = 100 Ω and XL = 100 Ω.
A. 1.10 A (lagging)
B. 1.55 A (lagging)
C. 2.20 A (lagging)
D. 4.40 A (lagging)
ANSWER: B
84. How many electrical degrees a current will lead the voltage in a series RC load with R = 100 Ω and XC = 50 Ω?
A. 13.28°
B. 26.56°
C. 31.72°
D. 63.44°
ANSWER: B
85. What will be the current equation in a series RC network if supplied with v = Vmsin120πt source. The circuit has a power factor pf = 0.5?
A. i = Imaxsin(120πt + 60)
B. i = Imaxsin(120πt - 60)
C. i = Imaxsin(120πt + 30)
D. i = Imaxsin(120πt - 30)
ANSWER: A
86. The power factor (pf) of a series LC circuit is
A. 0
B. 0.5
C. 0.75
D. 1.0
ANSWER: A
87. What is the power factor (pf) of a series RL circuit having R = 50Ω and XL = 20Ω?
A. 0.63
B. 0.71
C. 0.81
D. 0.93
ANSWER: D
88. A 200Ω resistor if connected in series with a capacitive reactance of 100 will give a total circuit impedance of
A. 173.2 Ω
B. 223.6 Ω
C. 250.6 Ω
D. 300.0 Ω
ANSWER: B
89. What will happen when the power factor of a circuit is increased?
A. reactive power increases
B. active power increases
C. both active and reactive powers
increases
D. both active and reactive powers
decreases ANSWER: B
90. A series RL network is supplied with a 200-volt, 60-cycle source. If the voltage across the resistor R is 100 V, what is the voltage across the inductor L?
A. 0 V
B. 100 V
C. 173.2 V
D. 200 V
ANSWER: C
91. A 6-Ω resistor is connected in series with a capacitive reactance of 8 Ω. If the supply voltage is 200 V, what is the power consumed by the circuit?
A. 2400 W
B. 4000 W
C. 5000 W
D. 6666.67 W
ANSWER: A
92. A 6-Ω resistor is connected in series with a capacitive reactance of 8 Ω. If the supply voltage is 200 V, what is the circuit current magnitude?
A. 14.28 A
B. 20 A
C. 25 A
D. 33.33 A
ANSWER: B
93. A 6-Ω resistor is connected in series with a capacitive reactance of 8 Ω. If the supply voltage is 200 V, what is the apparent power of the circuit?
A. 1200 W
B. 2400 W
C. 3200 W
D. 4000 W
ANSWER: D
94. The apparent power of a series RC network is given to be 4000 W. If R = 6 Ω, and XC = 8 Ω, calculate the true power of the network.
A. 1200 W
B. 2400 W
C. 3200 W
D. 4000 W
ANSWER: B
95. A series RC circuit has an apparent power of 4000 W. If R = 6Ω, and XC = 8Ω, determine the reactive power.
A. 1200 W
B. 2400 W
C. 3200 W
D. 4000 W
ANSWER: C
96. A network has a true power and a reactive power of 2400 W and 3200 W respectively. What is its apparent power?
A. 800 W
B. 1600 W
C. 4000 W
D. 5600 W
ANSWER: C
97. What is the total impedance of a series circuit consisting of R = 6Ω, XC = 8Ω, and XL = 16Ω?
A. 10 Ω
B. 14 Ω
C. 24.73 Ω
D. 30 Ω
ANSWER: A
98. What is the significance of connecting loads in parallel?
A. it makes power consumption less
B. it provides greater efficiency
C. it increases the safety factor
D. it allows independent operations of
loads ANSWER: D
99. A parallel RL circuit with R = 60Ω, and XL = 40Ω has a total impedance of
A. 24.3 Ω
B. 28.3 Ω
C. 33.3 Ω
D. 38.3 Ω
ANSWER: C
100. Calculate the total impedance of a parallel RC circuit if R = XC = 50Ω.
A. 25 @ 45° Ω
B. 25 @ -45° Ω
C. 35.35 @ 45° Ω
D. 35.35 @ -45° Ω
ANSWER: D
101. A 100-volt source is supplying a parallel RC circuit having a total impedance of 35.35Ω. Calculate the total line current.
A. 2.8345°
B. 2.83-45°
C. 4.0045°
D. 4.00-45°
ANSWER: A
102. What is the power factor of a circuit if the inductive susceptance and conductance have the same value?
A. 0.325
B. 0.525
C. 0.673
D. 0.707
ANSWER: D
103. If a circuit has an admittance of Y = 0.2 + j0.6, the circuit is
A. purely inductive
B. inductive
C. capacitive
D. reactive
ANSWER: C
104. The circuit admittance Y = 0.2 - j0.6, the circuit is
A. resistive
B. inductive
C. capacitive
D. reactive
ANSWER: B
105. What is the resonant frequency of a circuit when L is 50 microhenrys and C is 40 picofarads are in parallel?
A. 7.96 MHz
B. 79.6 MHz
C. 3.56 MHz
D. 1.78 MHz
ANSWER: C
106. If you need an LC circuit to be resonant at 2500 Hz and use a 150 mH coil, what should the capacitance value be?
A. 0.027 μF
B. 0.015 μF
C. 0.15 μF
D. 27 μF
ANSWER: A
107. What is the resonant frequency of a circuit when L of 3 microhenry and C of 40 picofarad are in series?
A. 1.33 MHz
B. 14.5 MHz
C. 14.5 kHz
D. 1.33 kHz
ANSWER: B
108. What is the resonant frequency of a circuit when L of 25 microhenry and C of 10 picofarad are in parallel?
A. 63.7 MHz
B. 10.1 MHz
C. 63.7 kHz
D. 10.1 kHz
ANSWER: B
109. A series circuit at resonance would mean, the circuit is
A. resistive
B. inductive
C. capacitive
D. reactive
ANSWER: A
110. Characteristics of the current in a series R-L-C circuit at resonance.
A. It is dc
B. It is a minimum
C. It is zero
D. It is at maximum
ANSWER: D
111. What is the cause of a minimum Q on a single-tuned LC circuit?
A. decreased series resistor
B. decreased shunt resistor
C. increased shunt resistor
D. decreased capacitance
ANSWER: C
112. Find the half-power bandwidth of a parallel resonant circuit, which has a resonant frequency of 3.6 MHz and a Q of 218.
A. 606 kHz
B. 58.7 kHz
C. 16.5 kHz
D. 47.3 kHz
ANSWER: C
113. A parallel circuit at resonance would mean, the circuit is
A. resistive
B. inductive
C. reactive
D. capacitive
ANSWER: A
114. What will happen to a parallel ac-circuit if its line frequency is more than the resonant frequency?
A. becomes purely resistive
B. becomes purely capacitive
C. becomes inductive
D. becomes capacitive
ANSWER: D
115. In a series ac-circuit, if the line frequency is more than the resonant frequency, the circuit behaves as
A. resistive
B. inductive
C. reactive
D. capacitive
ANSWER: B
116. If the line frequency of a parallel ac-circuit is less than the resonant frequency, the circuit behaves as
A. resistive
B. reactive
C. capacitive
D. purely inductive
ANSWER: B
117. If an ac-series circuit is supplied with a source whose frequency is less than that of fr, the circuit becomes
A. resistive
B. reactive
C. inductive
D. capacitive
ANSWER: D
118. _________ is a parallel LC circuit.
A. Parallel resisting circuit
B. Static circuit
C. Tank circuit
D. Hartley circuit
ANSWER: C
119. A parallel LC network with L = 100 mH and C = 25μF will resonate at what frequency?
A. 25 Hz
B. 45.5 Hz
C. 75.6 Hz
D. 100 Hz
ANSWER: D
120. Absolutely, when can we say that the circuit is at resonance?
A. when XL = XC
B. when the current is minimum
C. when the voltage and current are in-
phase
D. all of the above
ANSWER: C
TEST3.
1. The name of pure semiconductor material that has an equal number of electrons and holes
A. n-type B. pure type C. intrinsic D. p-type
ANSWER: C
2. Elements that has four valence electrons are classified as
A. conductor
B. insulator
C. elemental semiconductor
D. compound semiconductor
ANSWER: C
3. An example of an elemental semiconductor. A. Germanium (Ge) B. Gallium Arsenide (GaAs) C. Gallium Phosphide (GaP) D. Aluminum Arsenide (AlAs)
ANSWER A
4. Which of the following is an example of a compound semiconductor?
A. Gallium Arsenide (GaAs) B. Gallium Phosphide (GaP) C. Aluminum Arsenide (AlAs) D. All of the above
ANSWER: D
5. Germanium has an atomic number of 32 and an atomic weight of approximately 72 amu. How many electrons, protons and neutrons are there?
A. 32, 32, 40 B. 32, 32, 104 C. 40, 32, 32 D. 40, 32, 104
ANSWER: A
6. The chemical bond that is present in a crystal lattice of silicon atoms.
A. covalent bond B. electrovalent bond
C. ionic bond D. metallic bond
ANSWER: A
7. The atomic weight of a silicon atom is approximately 28 amu. How many electrons, protons and neutrons does the atom consist?
A. 14, 42, 14 B. 14, 14, 42 C. 42, 14, 14 D. 14, 14, 14
ANSWER: D
8. What is the total charge at the nucleus of silicon atom?
A. -12e C B. 12e C C. -14e C D. 14e C
ANSWER: D
9. In materials, what do you call the area that separates the valence band and the conduction
band? A. energy gap B. forbidden band C. insulation band D. A and B are correct
ANSWER: B
10. At absolute zero temperature, semiconductor acts as
A. an insulator B. a conductor C. a semi-insulator D. usual
ANSWER: A
11. The electron flow in a semiconductor material is A. opposite in direction of hole flow B. the same direction with hole flow C. the drift current D. known as the conventional current
ANSWER: A
12. Typical range of the resistivity of a semiconductor
A. 10-15 – 10-18 Ω-cm B. 10-5 – 10-8 Ω-cm C. 10 – 104 Ω-cm D. 108 – 1015 Ω-cm
ANSWER: C
13. Chemical bond that is significant in metals A. ionic bonding B. electrovalent bonding C. covalent bonding D. metallic bonding
ANSWER: D
14. A semiconductor that is free from impurities
A. intrinsic semiconductor B. extrinsic semiconductor C. compensated semiconductor D. elemental semiconductor
ANSWER: A
15. The process of adding impurities in a semiconductor material.
A. growing B. diffusion C. doping D. depleting
ANSWER: C
16. Impurities with five valence electrons. A. acceptor B. donor C. trivalent D. pentavalent
ANSWER: D
17. Example of acceptor impurities. A. pentavalent impurities
B. trivalent impurities C. tetravalent impurities D. hexavalent impurities
ANSWER: B
18. If the substance used in doping has less than four valence electrons, it is known as
A. acceptor B. donor C. trivalent D. pentavalent
ANSWER: A
19. Commonly used as donor impurities. A. Antimony (Sb) B. Arsenic (As) C. Phosphorus (P) D. all of the above
ANSWER: D
20. Example of trivalent impurities. A. Boron (B) B. Gallium (Ga) C. Indium (In) D. all of the above
ANSWER: D
21. Donor-doped semiconductor becomes a A. N-type semiconductor B. good conductor C. p-n semiconductor D. P-type semiconductor
ANSWER: A
22. What do you call a semiconductor that is doped with both donor and acceptor impurities?
A. double doped semiconductor B. compensated semiconductor
C. compound semiconductor D. diffused semiconductor
ANSWER: B
23. The resistance of a semiconductor is known as A. bulk resistance B. intrinsic resistance C. extrinsic resistance D. dynamic resistance
ANSWER: A
24. The most extensively used semiconductor. A. silicon B. germanium C. gallium phosphide D. gallium arsenide
ANSWER: A
25. Semiconductor whose electron and hole concentrations are equal.
A. extrinsic semiconductor B. intrinsic semiconductor C. compensated semiconductor
D. doped semiconductor ANSWER: B
26. Silicon is widely used over germanium due to its several advantages, what do you think is its most significant advantage?
A. abundant B. cheap C. temperature stable D. low leakage current
ANSWER: D
27. Current flow in a semiconductor that is due to the applied electric field.
A. diffusion current B. conventional current C. drift velocity D. drift current
ANSWER: D
28. The movement of charge carriers in a semiconductor even without the application of electric potential.
A. diffusion current B. conventional current C. drift current D. saturation current
ANSWER: A
29. Typically, how much energy is required for a valence electron to move to the conduction band for a doped semiconductor?
A. 0 eV B. 0.05 eV C. 1.0 eV D. 5.0 eV
ANSWER: B
30. Conduction of electrons in a doped semiconductor happens at
A. conduction band
B. forbidden band
C. valence band
D. nuclei band
ANSWER: A
31. Theoretically, where does the conduction of holes occur in a doped semiconductor?
A. conduction band B. forbidden band C. valence band D. empty band
ANSWER: C
32. In energy band diagram of a doped semiconductor, the donor level
A. is near the valence band B. is near the conduction band C. is exactly in between the valence and
conduction band D. depends on the amount of doping
ANSWER: B
33. The acceptor level in a doped semiconductor A. is near the valence band level B. is near the conduction level C. is exactly in between the conduction
and valence band D. will depend on the concentration of
doping ANSWER: A
34. In a semiconductor material, what will happen to the number of free electrons when the temperature rises?
A. increases B. decreases exponentially C. decreases D. remains the same
ANSWER: A
35. The electrical resistance of a semiconductor material will ________ as the temperature increases.
A. increase B. increase exponentially C. decrease D. not change
ANSWER: C
36. The potential required to removed a valence electron
A. valence potential B. threshold potential C. critical potential D. ionization potential
ANSWER: D
37. Among the given elements, which is considered as nonmetal?
A. silicon (Si) B. germanium (Ge) C. tin (Sn) D. lead (Pb)
ANSWER: A
38. A semiconductor that is classified as a metalloid or semimetal
A. silicon (Si) B. germanium (Ge) C. tin (Sn) D. carbon (C)
ANSWER: B
39. Semiconductor that is very rare, it only occurs in minute quantities in many metal sulfides
A. silicon (Si) B. germanium (Ge) C. tin (Sn) D. lead (Pb)
ANSWER: B
40. Compound semiconductors are also known as
A. compensated semiconductors B. amorphous semiconductors C. organic semiconductors D. inner-mettalic semiconductors
ANSWER: D
41. What semiconductor that is mostly used in devices requiring the emission or absorption of lights?
A. amorphous semiconductor B. organic semiconductor C. compound semiconductor D. elemental semiconductor
ANSWER: C
42. For high-speed integrated circuit, which semiconductor material given below is best to be used?
A. silicon B. germanium C. carbon D. gallium arsenide
ANSWER: D
43. How much impurity concentration is needed for a sample of silicon to change its electrical property from a poor conductor to a good conductor?
A. one part per hundred B. one part per thousand C. one part per million D. one part per billion
ANSWER: C
44. The restriction of certain discrete energy levels in a semiconductor material can be predicted generally by using what model?
A. Bohr model B. string model C. wave model D. particle model
ANSWER: A
45. Is defined as the energy acquired by an electron moving through a potential of one volt.
A. electron Joules (eJ) B. electron-potential C. oxidation potential D. electron Volt (eV)
ANSWER: D
46. At room temperature, in a perfect silicon crystal, the equilibrium concentration of thermally generated electrons in the conduction band is about
A. 1.5 x 105 per cubic cm. B. 1.5 x 1010 per cubic cm. C. 1.5 x 1015 per cubic cm. D. 1.5 x 1020 per cubic cm.
ANSWER: B
47. What is the basis in operation of semiconductor
photoconductors? A. EHP generation B. EHP degeneration C. EHP optical degeneration D. EHP optical generation
ANSWER: D
48. The semiconductor that is used in xerography A. selenium (Se) B. gallium phosphide (GaP) C. cadmium compound D. organic semiconductor
ANSWER: A
49. A silicon material has an intrinsic concentration ni=1010 per cubic centimeter at room temperature. If it is doped with 1015 antimony atoms per cubic centimeter, what is now the approximate electron concentration at the conduction band?
A. 105 electrons B. 1010 electrons C. 1015 electrons D. 1020 electrons
ANSWER: C
50. When an electron at the conduction band falls back to the valence band it will recombine with the hole. This is known as
A. regeneration B. reunion C. combination D. recombination
ANSWER: D
51. Which semiconductor is mostly used to detect near infrared?
A. silicon B. germanium C. carbon D. silicon carbide
ANSWER: D
52. What semiconductor that is good for high-temperature applications?
A. indium antimonide (InSb) B. gallium anitmonide(GaSb) C. silicon carbide (SiC) D. diamond (C)
ANSWER: A
53. Among the given semiconductors below, which has the highest mobility?
A. silicon B. germanium C. gallium arsenide D. indium antimonide
ANSWER: D
54. A semiconducting glass is known as
A. isomorphous semiconductor B. amorphous semiconductor C. organic semiconductor D. compound semiconductor
ANSWER: B
55. For an electroluminescent of green and red lights, which semiconductor is best?
A. silicon carbide B. gallium arsenide C. indium antimonide D. gallium phosphide
ANSWER: D
56. Typical range of power dissipation for a semiconductor to be considered as “low power” or “small signal”
A. less than 1 watt B. 5 < P < 10 watts C. 10 < P < 20 watts D. 20 watts above
ANSWER: A
57. In the design of high power semiconductor devices, it involves what factors?
A. making the size of the semiconductor bigger
B. packing the device into a bigger case C. excellent contact between the
semiconductor and the case D. all of the above
ANSWER: D
58. How to have a better high-frequency response in designing semiconductor devices?
A. make the chip as small as possible
B. the leads should be made shorter and smaller
C. smaller packaging D. all of the above
ANSWER: D
59. Before an electron can participate in the conduction of electricity, it must leave from the valence band and transfer to the conduction band. Transferring to the conduction band involves energy acquisition by an electron from external sources and this energy must be greater than the energy gap of the material. Which semiconductor material has the highest energy gap?
A. Zinc Sulfide (ZnS) B. silicon (Si) C. germanium (Ge) D. Indium Antimonide (InSb)
ANSWER: A
60. Which of the following semiconductors has the smallest energy gap?
A. ZnS B. Si C. Ge D. InSb
ANSWER: D
61. The ease with which a charge carrier (electron or hole) moves in a semiconductor material is known as mobility. It is also defined as the average drift velocity of electrons and holes per unit electrostatic field. Which of the semiconductor materials has the highest value of electron-mobility?
A. InSb B. Ge C. Si D. AlP
ANSWER: A
62. In semiconductor materials, electrons have a higher value of mobility than holes, but which semiconductor material has the slowest electron-mobility?
A. InSb B. GaP C. GaAs D. AlP
ANSWER: D
63. Solar cell is a semiconductor electric-junction device, which absorbs the radiant energy of sunlight and converts it directly and efficiently into electrical energy. This device, uses what type of semiconductor materials?
A. single-crystal silicon B. amorphous or polycrystalline silicon C. GaAs, CdS, CdTe, CuS D. all of the above
ANSWER: D
64. What is formed when n-type and p-type semiconductors are brought together?
A. pn junction B. semiconductor junction C. energy band gap D. semiconductor diode
ANSWER: A
65. PN junction acts as a one way valve for electrons because _________.
A. the circuit in which the diode is used, only attempts to pump electrons in one diode
B. electrons tend to follow the direction of the hole
C. there is a little mechanical switch inside a diode
D. when electrons are pump from P to N, free electrons and holes are force apart leaving no way for electrons to cross the junction
ANSWER: D
66. The device that is formed when an n-type and p-type semiconductors are brought together
A. pn junction B. semiconductor junction C. depletion region D. junction diode
ANSWER: D
67. An external voltage applied to a junction reduces its barrier and aid current to flow through the junction
A. reverse bias B. external bias C. junction bias D. forward bias
ANSWER: D
68. A device containing an anode and a cathode or a pn junction of a semiconductor as the principal elements and provides unidirectional conduction.
A. diode B. diac C. triode D. triac
ANSWER: A
69. Unidirectional conduction in two-electrodes in any device other than a diode, such that rectification between the grid and cathode of a triode, or asymmetrical conduction between the collector and base of a transistor is called
A. rectification B. diode action C. clipping D. clamping
ANSWER: B
70. The p-type material in a semiconductor junction
diode is technically termed as A. positive terminal B. negative terminal C. cathode D. anode
ANSWER: D
71. Cathode in a semiconductor junction diode is referred to the
A. positive terminal B. junction C. p-type terminal D. n-type terminal
ANSWER: D
72. The area in the semiconductor diode where there are no charge carriers
A. depletion layer B. depletion region C. depletion mode D. depletion area
ANSWER: B
73. Depletion region is an area in a semiconductor device where there are no charge carriers exist. This will be always near the junction of n-type and p-type materials. What causes this junction to be depleted by charge carriers?
A. Due to the recombination of holes and electrons at the junction
B. Due to the cancellation of positively charge protons and negatively charge electrons
C. Due to the annihilation of charge carriers
D. Due to the combination of positively charge holes and negatively charge electrons
ANSWER: D
74. A junction diode is said to be forward-biased if A. Anode is supplied more positive than
the cathode. B. Anode is supplied more negative than
the cathode. C. A voltage greater than threshold is
applied, with cathode less positive than anode.
D. A voltage greater than threshold is applied, with cathode less negative than anode.
ANSWER: C
75. What do you call the very small amount of current that will flow in the diode when it is reverse biased?
A. saturation current B. reverse saturation current C. cut-off current
D. holding current ANSWER: B
76. When the diode is supplied with forward direction potentials but with a magnitude less than the threshold voltage of the diode, still it will not “turn-on” and will only allow a very small amount of current to pass. This very small current is known
A. as leakage current B. as forward saturation current C. as holding current D. as cut-off current
ANSWER: D
77. The minimum voltage required before a diode can totally conduct in a forward direction.
A. triggering voltage B. breakdown voltage C. saturation voltage D. threshold voltage
ANSWER: D
78. What will happen to the threshold voltage of the diode when it operates at higher temperatures.
A. increases B. increases exponentially C. decreases D. decreases exponentially
ANSWER: C
79. The forward current in a conducting diode will ______________ as the operating temperature increases.
A. not be affected B. decrease C. decrease exponentially D. increase
ANSWER: D
80. As the operating temperature of a reverse-biased diode is increased, its leakage or reverse saturation current will
A. Increase B. increase exponentially C. decrease D. decrease exponentially
ANSWER: B
81. The small value of direct current that flows when a semiconductor device has reverse bias
A. surge current B. bias current C. reverse current D. current limit
ANSWER: C
82. Normally, diodes will not conduct when reverse-biased, but if the reverse voltage is increased further, a point will be reached where the diode gives up and allowing the current to surge. This
voltage is one of the limiting parameter of diodes and is known as
A. breakdown voltage (VBR) B. peak inverse voltage (PIV) C. peak reverse voltage (PRV) D. all are correct
ANSWER: D
83. For a silicon diode, calculate the current at room temperature if the forward voltage VF = 0.3 V and the reverse saturation current IS = 100 nA.
A. 32.8 μA B. 10.8 μA C. 32.8 mA D. 10.8 mA
ANSWER: A
84. The breakdown voltage of a junction diode will ___________
A. Increase as operating temperature rises.
B. Increase exponentially as operating temperature rises.
C. Decrease as operating temperature rises.
D. Not change as operating temperature rises.
ANSWER: C
85. Calculate the new threshold voltage of a germanium diode when it operates at 100 0C.
A. 0.113 V B. 0.188 V C. 0.215 V D. 0.513 V
ANSWER: A
86. A silicon diode has a reverse saturation current of 50 nA at room temperature. If the operating temperature is raised by 50°C, what is now the reverse saturation current?
A. 105.56 nA B. 287.73 nA C. 827.89 nA D. 1.66 µA
ANSWER: D
87. In every increase of 10°C in the operating temperature of a diode will cause its reverse saturation current to
A. decrease B. double C. triple D. quadruple
ANSWER: B
88. What do you call the resistance of the diode when operating at a steady state voltage?
A. dc resistance B. dynamic resistance C. ac resistance
D. average resistance ANSWER: A
89. The resistance of the diode that is significant when operating with a small ac signal
A. dc resistance B. static resistance C. dynamic resistance D. average resistance
ANSWER: C
90. When a diode is used in large ac voltages, the resistance that is to be considered is
A. dc resistance B. static resistance C. dynamic resistance D. average resistance
ANSWER: D
91. At forward bias condition, what will happen to the diode resistance when the applied voltage is increased?
A. will also increase
B. will increase exponentially C. will decrease D. will not change
ANSWER: C
92. The primary use of Zener diode in electronic circuits.
A. resistance regulator B. rectifier C. voltage regulator D. current regulator
ANSWER: C
93. What phenomenon in electronics does an avalanche breakdown primarily dependent?
A. Doping B. Recombination C. Ionization D. Collision
ANSWER: C
94. When a diode is reverse biased the depletion region widens, since it is in between positively charge holes and negatively charge electrons, it will have an effect of a capacitor, this capacitance is called what?
A. diffusion capacitance B. storage capacitance C. stray capacitance D. transition capacitance
ANSWER: D
95. In a semiconductor diode, the total capacitance, that is the capacitance between terminals and electrodes, and the internal voltage variable capacitance of the junction is called
A. diffusion capacitance B. transition capacitance
C. depletion-region capacitance D. diode capacitance
ANSWER: D
96. What capacitance is significant when the diode is forward biased?
A. diffusion capacitance or storage capacitance
B. transition capacitance C. depletion-region capacitance D. stray capacitance
ANSWER: A
97. A diode that is especially designed to operate as a voltage-variable capacitor. It utilizes the junction capacitance of a semiconductor diode.
A. varactor B. varicap C. varistor D. A and B are correct
ANSWER: D
98. The capacitance of a varactor will _______ when
the forward bias voltage is increased. A. increase B. decrease C. exponentially decrease D. not change
ANSWER: A
99. The time taken by the diode to operate in the reverse condition from forward conduction
A. reverse recovery time B. forward recovery time C. reverse holding time D. reverse time constant
ANSWER: A
100. In operating a diode at high-speed switching circuits, one of the most important parameters to be considered is
A. ac resistance B. diode capacitance C. noise figure D. reverse recovery time (trr)
ANSWER: D
101. The time required for forward voltage or current to reach a specified value after switching the diode from its reverse-to-forward-biased state.
A. reverse recovery time B. forward recovery time (tfr) C. saturation time D. conduction time
ANSWER: B
102. The maximum power the diode can handle. A. maximum derating power B. maximum consumption power C. breakdown power D. maximum dissipation power
ANSWER: D
103. What is the most important specification for semiconductor diode?
A. Forward resistance B. Reverse resistance C. Peak inverse voltage D. Current capacity
ANSWER: D
104. What will happen to the power handling capability of the diode if it is to be operated at a higher temperature?
A. decreases B. increases C. increases exponentially D. will not be affected
ANSWER: A
105. Diode parameter that will inform the user as to what factor does the power handling capability of the diode is reduced as the operating temperature is increased.
A. power derating factor B. power dissipating factor C. power reduction constant D. all of the above
ANSWER: A
106. A certain diode has a maximum power dissipation of 500 mW at room temperature and a linear power derating factor of 5.0 mW/°C. How much power the diode can handle if operated at 50°C.
A. 625 mW B. 505 mW C. 495 mW D. 375 mW
ANSWER: D
107. A semiconductor device especially fabricated to utilize the avalanche or zener breakdown region. This is normally operated in the reverse-region and its application is mostly for voltage reference or regulation.
A. varactor diode B. zener diode C. shockley diode D. Schottky barrier diode
ANSWER: B
108. Refers to a special type of diode which is capable of both amplification and oscillation.
A. Junction diode B. Tunnel diode C. Point contact diode D. Zener diode
ANSWER: B
109. The effect obtain when the electric field across a semiconductor is strong enough which causes
the free electrons to collide with valence electrons, thereby releasing more electrons and a cumulative multiplication of charge carriers occur.
A. Gunn
B. avalanche
C. tunneling
D. diffusion
ANSWER: B
110. A negative resistance diode commonly used in microwave oscillators and detectors, it is sometimes used as amplifiers. This device is also known as Esaki diode.
A. varactor diode
B. Schottky diode
C. IMPATT diode
D. tunnel diode
ANSWER: D
111. A rectifying metal-semiconductor junction
A. Schottky barrier diode
B. surface barrier diode
C. hot-carrier or hot-electron diode
D. all of the above are correct
ANSWER: D
112. Diode whose negative resistance depends on a specific form of quantum-mechanical bond structure of the material
A. Gunn diode B. tunnel diode C. TRAPATT diode D. backward diode
ANSWER: A
113. One of the electronic semiconductor devices known as diac, function as
A. Four terminal multi-directional switch B. Two terminal bi-directional switch C. Two terminal unidirectional switch D. Three terminal bi-directional switch
ANSWER: C
114. Another name of a three-layer diode. This is also considered as an ac diode.
A. Shockley diode B. thyrector C. thyristor D. diac
ANSWER: D
115. A diode whose negative resistance is dependent on the classical effects of phase shift introduced by the time lag between maximum field and maximum avalanche current, and by the transit time through the device.
A. Read diode
B. IMPATT diode C. TRAPATT diode D. all of the above
ANSWER: D
116. What semiconductor diode that have a fine wire (called a cat-whisker) whose point is in permanent contact with the surface of a wafer of semiconductor material such as silicon, germanium or gallium arsenide?
A. point-contact diode B. diac C. PiN diode D. thyrector
ANSWER: A
117. When the p-n junction of a semiconductor diode is inserted with an intrinsic material, the diode becomes a
A. backward diode B. Read diode C. Schokley diode D. PiN diode
ANSWER: D
118. A four layer semiconductor diode whose characteristic at the first quadrant is similar to that of a silicon-controlled rectifier (SCR).
A. Shockley diode B. thyrector C. Schottky diode D. diac
ANSWER: A
119. A diode that is especially processed so that its high-current flow takes place when the junction is reverse-biased. It is a variation of a tunnel diode.
A. Esaki diode B. Read diode C. zener diode D. backward diode
ANSWER: D
120. A silicon diode that exhibits a very high resistance in both directions up to certain voltage, beyond which the unit switches to a low-resistance conducting state. It can be viewed as two zener diodes connected back-to-back in series.
A. bizener diode B. diac C. thyristor D. thyrector
ANSWER: D
121. A type of Read diode that uses a heavily doped n-type material as its drift region
A. IMPATT diode B. TRAPATT diode C. TUNNETT diode
D. MITATT ANSWER: A
122. A device containing more than one diode. An example is the full-wave bridge-rectifier integrated circuit.
A. diode array B. diode IC C. diode pack D. combined diode
ANSWER: C
123. Is the combination of the inductance of the leads and electrodes, capacitance of the junction, and the resistance of the junction of a semiconductor diode.
A. diode impedance B. diode ac resistance C. diode reactance D. diode ac parameter
ANSWER: A
124. In a reverse-biased pn junction, the sudden
large increase in current that occurs when a particular value of reversed voltage is reached, and which is due to ionization by the high intensity electric field in the depletion region.
A. Zener effect B. Hall effect C. breakdown voltage D. ionization
ANSWER: A
125. The appearance of RF current oscillations in a dc-biased slab of n-type gallium arsenide in a 3.3 kV electric field
A. Gunn effect B. Hall effect C. Zener effect D. avalanche
ANSWER: A
126. The impedance presented by a junction operating in its zener breakdown region.
A. diode impedance B. zener impedance C. breakdown impedance D. critical impedance
ANSWER: B
127. A curve showing the relationship between the voltage and the current of the diode at any given temperature
A. characteristic curve B. transfer curve C. transfer characteristic curve D. all are correct
ANSWER: A
128. The line that is plotted in the diode characteristic curve which represents the load
A. linear line B. operating line C. load line D. transfer load line
ANSWER: C
129. Diode is said to be operating at a point where the characteristic curve and the load line intersect. This point is technically termed as
A. Q-point
B. operating point
C. quiescent point
D. all are correct
ANSWER: D
130. What will happen to the magnitude of the load-line slope when the load resistance is decreased?
A. it will also decrease
B. it will increase
C. it will increase exponentially
D. is not affected by the load
ANSWER: B
131. Quiescent or Q-point position is dependent on
A. the supply voltage
B. the load resistance
C. the type of diode
D. all of the above
ANSWER: D
132. A germanium diode is connected to a load resistance of 1.5 kΩ and is supplied with 12-V such that the diode will be forward biased. What is the voltage across the diode?
A. approximately 12 V
B. approximately 0.7 V
C. approximately 0.3 V
D. lack of data and can’t be solved
ANSWER: C
133. What is the drop across the diode when it is connected in series to a resistor of 1.8 kΩ and a supply voltage of 50 V. The supply voltage causes the diode to be reverse-biased.
A. 50 V
B. 0.7 V
C. 0.3 V
D. can not be solve, lack of data
ANSWER: A
134. Two germanium diodes are connected in series and have a load resistance of 10 kΩ and a forward supply voltage of 5 V. Calculate the voltage across the load resistor.
A. 4.7 V
B. 4.4 V
C. 0.6 V
D. 0.3 V
ANSWER: B
135. A silicon diode is in parallel with a germanium diode and is connected to a load resistor having a value of 20 kΩ and a forward supply voltage of 10 V. What is the approximate voltage across the silicon diode?
A. 10 V
B. 1.0 V
C. 0.7 V
D. 0.3 V
ANSWER: D
136. What is the output voltage across a load resistor if it is paralleled with a forward biased silicon diode? The resistor network is supplied with 10 V.
A. 0.7 V
B. 9.3 V
C. 10 V
D. Can’t be solve, lack of data.
ANSWER: A
137. Diode circuit that is used to cut a portion of the input signal
A. clipper
B. clamper
C. peak detector
D. level shifter
ANSWER: A
138. A clipper circuit wherein the diode is connected in series with the load
A. series clipper
B. parallel clipper
C. shunt clipper
D. series feed clipper
ANSWER: A
139. What do you call a clipper circuit wherein the diode is shunted with the load?
A. series clipper
B. parallel clipper
C. cascade clipper
D. cascade clipper
ANSWER: B
140. A network with a diode and a capacitor that is used to shift the dc-level of the input signal
A. clipper
B. clamper
C. shifter
D. level inverter
ANSWER: B
141. Half-wave rectifier is a good example of
A. a series clamper
B. a parallel clamper
C. a parallel clipper
D. a series clipper
ANSWER: D
142. Which of the given circuit below must have a capacitor?
A. rectifier
B. clipper
C. clamper
D. all of the above
ANSWER: C
143. How many capacitors are used in a diode-capacitor half- wave voltage doubler?
A. 1
B. 2
C. 3
D. 4
ANSWER: B
144. An improvement of a diode-capacitor half-wave voltage doubler is the full-wave doubler, this circuit uses how many capacitors?
A. 1
B. 2
C. 3
D. 4
ANSWER: B
145. In a diode-capacitor voltage quadrupler, what is the voltage across the third stage capacitor?
A. Vmax
B. 2 Vmax
C. 3 Vmax
D. 4 Vmax
ANSWER: B
146. A combination of several diodes in a single housing
A. diode array
B. diode network
C. diode IC
D. diode matrix
ANSWER: A
147. A chopper, employing an alternately biased diodes as the switching element.
A. diode chopper
B. active chopper
C. junction chopper
D. all are correct
ANSWER: A
148. A light emitting diode (LED) is to be used in a circuit with a supply voltage of 5 V. What should be the value of the resistor needed by the LED to operate normally?
A. 25 Ω
B. 250 Ω
C. 25 kΩ
D. 250 kΩ
ANSWER: B
149. A simple voltage-regulator whose output is the constant voltage drop developed across a zener diode conducting in the reverse breakdown region. The regulator circuit consists of a zener diode in parallel with the load and an appropriate limiting resistor.
A. ordinary voltage regulator
B. zener voltage regulator
C. series voltage regulator
D. switching voltage regulator
ANSWER: B
150. Logic circuitry in which a diode is the logic element and a transistor acts as an inverting amplifier.
A. RTL
B. DTL
C. HDTL
D. ECL
ANSWER: B
151. What is a bridge rectifier having diodes in two arms and resistors in the other two?
A. full-wave bridge
B. half-wave bridge
C. half-bridge
D. full bridge
ANSWER: C
152. An over-voltage protection circuit employing a zener diode and an SCR whose function is to produce high overload by-pass current on a circuit.
A. regulator
B. current enhancer
C. crowbar
D. shunted zener
ANSWER: C
153. The flow of electron in a NPN transistor when used in electronic circuit is from _______.
A. collector to base
B. collector to base
C. emitter to collector
D. base to emitter
ANSWER: C
154. A three terminal, three layer semiconductor device that has the ability to multiply charge carriers. This device was first introduced at Bell Laboratories, by Brattain and Bardeen in 1947 and which opens a completely new direction of interest and development in the field of electronics.
A. triode
B. triac
C. SCR
D. transistor
ANSWER: D
155. An active semiconductor device, capable of amplification, oscillation, and switching action. It is an acronym for transfer resistor and had replaced the tube in most applications.
A. thyristor
B. thyrector
C. SBS
D. transistor
ANSWER: D
156. Transistor replaces the old vacuum tubes because it has several obvious advantages, what are they?
A. smaller, lightweight and rugged
construction
B. no heater loss, low operating voltage
and therefore efficient
C. low power consumption and low power
dissipation
D. all of the above
ANSWER: D
157. Which of the three regions/areas in a transistor that is the smallest in construction?
A. emitter
B. collector
C. base
D. all are equal
ANSWER: C
158. The region or area in a transistor that is heavily doped
A. at the junction
B. emitter
C. collector
D. base
ANSWER: B
159. A transistor in which the base is diffused and the emitter is alloyed. The collector is provided by the semiconductor substrate into which alloying and diffusion are affected.
A. alloy-transistor
B. alloy-diffused transistor
C. alloy junction transistor
D. diffused junction transistor
ANSWER: B
160. A transistor whose junctions are created by alloying
A. alloy transistor
B. alloy-diffused transistor
C. diffused transistor
D. alloy junction
ANSWER: A
161. In a semiconductor device, a p-n junction formed by alloying a suitable material such as indium with the semiconductor.
A. alloy junction
B. diffused junction
C. depletion junction
D. storage junction
ANSWER: A
162. A transistor in which one or both electrodes are created by diffusion
A. diffused transistor
B. alloy transistor
C. planar transistor
D. mesa transistor
ANSWER: A
163. A two-junction transistor whose construction takes the form of a pnp or a npn. Such device uses both electron and hole conduction and is current-driven.
A. bipolar transistor
B. unipolar transistor
C. bi-directional transistor
D. double junction transistor
ANSWER: A
164. The predecessor of the junction transistor, and is characterized by a current amplification factor, alpha of greater than one.
A. surface-charge transistor
B. surface-barrier transistor
C. schottky transistor
D. point-contact transistor
ANSWER: D
165. For a transistor, the outer layers are
A. lightly doped semiconductors
B. heavily doped semiconductors
C. no doping at all
D. A and B above
ANSWER: B
166. The ratio of the total width of the outer layers to that of the center layer
A. 100:1
B. 150:5
C. 150:1
D. 1:150
ANSWER: C
167. The ratio of the doping level of the outer layers to that of the sandwiched material
A. 10:3 or more
B. 10:2 or more
C. 10:3
D. 10:1 or less
ANSWER: D
168. Limiting the number of “free” carriers will
A. increase the conductivity but decreases
the resistance
B. decrease the conductivity but increases
the resistance
C. increase the conductivity as well as
resistivity
D. decrease the conductivity as well as
resistivity ANSWER: B
169. The term ________ reflects the fact that holes and electrons participate in the injection process into the oppositely polarized material.
A. unipolar
B. bipolar
C. tetrode
D. pentode
ANSWER: B
170. What device, that employs only electron or hole?
A. unipolar
B. bipolar
C. tetrode
D. pentode
ANSWER: A
171. At forward-biased junction of pnp transistor, majority carriers flow heavily
A. from p- to the n-type material
B. from n- to the p-type material
C. from p- to p-type material
D. A and B above
ANSWER: A
172. The minority-current component of a transistor is called
A. leakage current
B. emitter current
C. cut-off current
D. all of the above
ANSWER: A
173. For general-purpose transistors, IC is measured in ____, while ICO is measured in ____.
A. micro and nanoamperes
B. milliamperes and microamperes
C. milliamperes and nanoamperes
D. b and c above
ANSWER: D
174. Is temperature sensitive, and can severely affect the stability of the system, when not carefully examined during design
A. IC
B. ICO
C. IS
D. IE
ANSWER: B
175. For the transistor, the arrow in the graphic symbol defines the direction of _______ through the device
A. leakage current flow
B. emitter electron flow
C. majority carrier flow
D. emitter conventional current flow
ANSWER: D
176. In the dc mode, the levels of IC and IE due to the majority carriers are related by the quantity
A. alpha (α)
B. beta (β)
C. gamma (γ)
D. A and B above
ANSWER: A
177. In the ac mode, alpha α is formally called
A. common-base, short-circuit,
amplification factor
B. common-emitter, amplification factor
C. common-collector, amplification factor
D. all of the above are correct
ANSWER: A
178. Phrases “not pointing in” and “pointing in” simply mean
A. npn and pnp
B. pnp and npn
C. npn only
D. pnp only
ANSWER: A
179. In the dc mode, the levels of IC and IB are related by a quantity called
A. α
B. β
C. γ
D. A and B above
ANSWER: B
180. For practical transistor devices, the level of β typically ranges
A. from about 25 to over 400
B. less than 1
C. mostly in midrange of 50 to 400
D. A or C above
ANSWER: C
181. The formal name of βac
A. Common-collector reverse-current
amplification factor
B. Common-collector forward-current
amplification factor
C. Common-emitter forward-current
amplification factor
D. Common-emitter reverse-current
amplification factor ANSWER: C
182. It is a particularly important parameter that provides a direct link between current levels of the input and output circuits for a common-emitter configuration.
A. α
B. β
C. A and B above
D. none of the above
ANSWER: B
183. The _______ id defined as that area below IC= ICEO.
A. active region
B. cutoff region
C. saturation region
D. none of the above
ANSWER: B
184. It is referred to as the communication link between the manufacturer and user
A. specification sheet
B. characteristic manual
C. characteristic curve
D. all of the above
ANSWER: D
185. The information that can be found in most specification sheets?
A. maximum ratings
B. thermal characteristics
C. electrical characteristics
D. all of the above
ANSWER: D
186. With an ohmmeter, a large or small resistance in either junction of an npn or pnp transistor indicates
A. faulty device
B. well functioning device
C. leaky device
D. either A or C
ANSWER: A
187. At base-emitter junction, using an ohmmeter, if the positive (+) lead is connected to the base and the negative (-) lead to the emitter, a low resistance reading would indicate
A. npn transistor
B. pnp transistor
C. germanium transistor
D. silicon transistor
ANSWER: A
188. At base-emitter junction, if the positive (+) lead is connected to the base and the negative (-) lead to the emitter, a high resistance reading would indicate
A. npn transistor
B. pnp transistor
C. germanium transistor
D. silicon transistor
ANSWER: B
189. Transistors of heavy duty construction
A. high-power devices
B. low-power devices
C. medium-power devices
D. all of the above
ANSWER: A
190. On a voltage-current condition curve, the point belong to which a further increase in voltage produces no (or very little) further increase in current.
A. saturation flux
B. saturation value
C. saturation point
D. all of the above
ANSWER: C
191. It is applied to any system where levels have reached their maximum values
A. saturation
B. active
C. cutoff
D. quiescent point
ANSWER: A
192. For an “on” transistor, the voltage VBE should be in the neighborhood of
A. 0.3 V
B. 0.55 V
C. 0.7 V
D. 1.7 V
ANSWER: C
193. Among the three characteristics of a transistor amplifier, which region is normally employed for linear (undistorted) amplifiers?
A. active region
B. cutoff region
C. saturation region
D. capital region
ANSWER: A
194. In the active region, the collector-base junction is ________, while the base-emitter junction is ________.
A. forward and forward-biased
B. forward and reverse-biased
C. reverse and reverse biased
D. reverse and forward-biased
ANSWER: D
195. It is necessary, in order to establish the proper region of operation for ac amplification.
A. ac biasing
B. dc biasing
C. A and B above
D. none of the above
ANSWER: B
196. At cutoff region, the collector-base and base-emitter junctions of a transistor are
A. both reverse-biased
B. forward and reverse-biased
C. both forward-biased
D. reverse and forward-biased
ANSWER: A
197. In saturation region, the collector-base and base-emitter junctions of a transistor are
A. both reverse-biased
B. forward and reverse-biased
C. both forward-biased
D. reverse and forward-biased
ANSWER: C
198. If the base-emitter junction is reverse biased and the base-collector junction is forward biased, the transistor will be at what region of operation?
A. active region
B. cut-off region
C. saturation region
D. breakdown region
ANSWER: B
199. Under what region does the transistor operate if both the base-emitter and base-collector junctions are reverse-biased?
A. active region
B. cut-off region
C. saturation region
D. breakdown region
ANSWER: B
200. What region the transistor should be operating to have minimum distortion at the output signal?
A. active region
B. cut-off region
C. saturation region
D. none of the above
ANSWER: A
201. In dc biasing, it means quiet, still, inactive
A. passive
B. quench
C. static
D. quiescent
ANSWER: D
202. The transistor terminal that handles most current
A. base
B. collector
C. emitter
D. collector and emitter
ANSWER: C
203. Which indicates the degree of change, in operating-point due to temperature variation in the dc biasing?
A. temperature coefficient
B. factor of safety
C. merit factor
D. stability factor
ANSWER: D
204. What best describes the transistor current that flows between the collector and emitter terminals when the base is open?
A. leakage current
B. cut-off current
C. reverse saturation current
D. all of the above
ANSWER: B
205. Solve for the base current if collector current is 600 mA and the current gain is 20.
A. 30 mA
B. 3 mA
C. 12 mA
D. 1.2 mA
ANSWER: A
206. When the transistor is saturated, VCE is approximately
A. 0 V
B. ½ VCC
C. VCC
D. infinite
ANSWER: A
207. Collector-emitter resistance of ideal transistor at cut-off
A. 0 Ω
B. infinite
C. a function of the load resistance
D. a function of the collector current
ANSWER: B
208. The leakage current that flows at the collector-base junction when the emitter is open
A. ICO
B. ICBO
C. ICEO
D. ICBE
ANSWER: B
209. A transistor with β = 100 is connected as common base, was found to have a leakage current ICBO = 1µA. If the transistor is configured as common emitter, what is the approximate value of its ICEO?
A. 0.01 µA
B. 1.0 µA
C. 100 µA
D. 10 mA
ANSWER: C
210. The most correct technical term of the reverse leakage current that flows between the collector and base junctions when the emitter is open circuited.
A. leakage current
B. saturation current
C. reverse saturation current
D. cut-off current
ANSWER: C
211. How is the collector cut-off or reverse saturation current ICBO related to the emitter cut-off current IEBO?
A. ICBO β IEBO p
B. ICBO IEBO/β
C. ICBO IEBO(1-α)
D. ICBO IEBO
ANSWER: D
212. ICBO of an ideal transistor
A. increases as temperature increases
B. increases as temperature decreases
C. is not affected by a temperature change
D. is zero (0) mA
ANSWER: D
213. The maximum voltage that can be applied across the collector-emitter terminal for a given transistor is specified as
A. VCEO
B. VECO
C. V(BR)BEO
D. V(BR)CEO
ANSWER: D
214. If the current-gain-bandwidth product of transistor is 250 MHz and is operated at 100 MHz, what is the effective current gain of the transistor?
A. 2.5
B. 25
C. 250
D. 350
ANSWER: A
215. The current gain of a transistor decreases as the operating frequency increases. As the operating frequency is increased continuously, a point occurs where the current gain becomes unity. This point, is best described by what transistor parameter?
A. unity gain frequency
B. 0 dB frequency
C. cut-off frequency
D. unity gain bandwidth product or unity
current gain bandwidth product ANSWER: D
216. When base is common to both the input and output sides of the configuration and is usually the terminal closes to, or at ground potential, it is called what?
A. common-emitter terminology
B. common-collector terminology
C. common-base terminology
D. all of the these
ANSWER: C
217. Which transistor configuration has the highest input resistance?
A. common base
B. common emitter
C. common collector
D. common transistor
ANSWER: C
218. One of the following amplifier characteristic refers to that of a common-base (C-B) as compared to common-emitter (C-E) and common-collector (C-C) amplifiers.
A. Has larger current gain
B. Has lower input resistance
C. Has higher input resistance
D. Has larger voltage gain
ANSWER: B
219. A transistor is said to be configured as common emitter if the emitter terminal is
A. grounded
B. connected to V+
C. floating
D. not used as an input nor output
ANSWER: D
220. Most frequently used transistor configuration for pnp and npn
A. common-base
B. common-collector
C. common-emitter
D. A and C above
ANSWER: C
221. Calculate the common-emitter amplification factor β of a transistor with a common-base amplification factor α=0.99.
A. 10
B. 50
C. 100
D. 200
ANSWER: C
222. Which transistor configuration hybrid parameters, that is usually specified by the manufacturers?
A. for common-base
B. for common-collector
C. for common-emitter
D. a combination of the three
configurations ANSWER: C
223. For a common-emitter transistor configuration, the hybrid parameter hfe stands for forward transfer current ratio. This parameter is approximately equal to
A. HFE
B. βac
C. β
D. all of the above
ANSWER: D
224. Hybrid parameter that is usually neglected in circuit analysis
A. hi and ho
B. hr and hf
C. hi and hf
D. hr and ho
ANSWER: D
225. The input impedance of a common-base configuration is hib, and its magnitude is approximately equal to
A. hie/hfe
B. hie/(1+β)
C. re for dynamic model
D. all of these
ANSWER: D
226. In most transistor input equivalent circuit it comprises of a resistor and a
A. voltage source
B. stiff voltage source
C. current source
D. stiff current source
ANSWER: A
227. Which transistor configuration has the highest input resistance?
A. common-base
B. common-collector
C. common-emitter
D. emitter follower
ANSWER: B
228. Common-base configuration has a high voltage gain and a current gain of
A. low
B. moderate
C. high
D. approximately equal to one (1)
ANSWER: D
229. Common-collector has the lowest power gain and a voltage gain of approximately one. In contrast to this, what configuration has the highest power gain?
A. common-base
B. common-collector
C. common-emitter
D. emitter follower
ANSWER: C
230. Which of the following transistor characteristic curves that is most useful?
A. input characteristic curve
B. output characteristic curve
C. transfer characteristic curve
D. all of the above
ANSWER: B
231. The graph of the product of collector-emitter voltage VCE and collector current IC in the transistor output characteristic curve.
A. maximum power curve
B. minimum power curve
C. saturation power curve
D. breakdown curve
ANSWER: A
232. The base of a transistor serves a purpose to what element of the FET?
A. source
B. ground
C. substrate
D. gate
ANSWER: D
233. What is the primary difference between the BJT and the FET?
A. current-controlled device and voltage-
controlled device, respectively
B. voltage-controlled device and current-
controlled device, respectively
C. impedance transformed device and
conductance transformed device, respectively
D. A and C above are correct
ANSWER: A
234. Another difference between a BJT and a FET with regards to its normal biasing.
A. The input circuit is forward-biased for
BJT while reverse for FET.
B. The input circuit is reverse-biased for
BJT while forward for FET.
C. The output circuit is forward-biased for
BJT while reverse for FET.
D. The output circuit is reverse-biased for
BJT while forward for FET. ANSWER: A
235. Field-effect transistors (FETs) offer high input impedance than BJT. What makes FETs have high input impedance?
A. The way FETs are constructed.
B. Because of the materials used.
C. Due to the level of doping
D. Due to the reverse-biased input circuit
of FETs ANSWER: D
236. The operation of BJT involves both the flow of electrons and holes and is therefore, considered as a bipolar device. Unlike BJT, FET’s operation involves only either electrons or holes and is considered as a _________ device.
A. single polar
B. unipolar
C. unpolar
D. polarized
ANSWER: B
237. Considered as the basic FET or the simplest form of FET
A. JFET
B. MOS-FET
C. IGFET
D. VMOS-FET
ANSWER: A
238. Junction field effect transistor or JFET has three terminals, which corresponds to the E-B-C of the BJT?
A. D-S-G
B. D-G-S
C. S-G-D
D. S-D-G
ANSWER: C
239. One obvious advantage of a JFET over BJT is its
A. high voltage gain
B. high current gain
C. high input resistance
D. high output resistance
ANSWER: C
240. A BJT is a current-controlled current-source device while JFET is a _________ device.
A. current-controlled voltage-source
B. voltage-controlled voltage-source
C. voltage-controlled current-source
D. voltage-controlled transconductance-
source ANSWER: C
241. What do you call the area in a JFET where current passes as it flows from source (S) to drain (D).
A. channel
B. substrate
C. depletion
D. drift
ANSWER: A
242. What will happen to the channel of a JFET as current flows to it?
A. widens
B. narrows
C. skews
D. nothing
ANSWER: C
243. For a normal operation of an n-channel JFET, how do you bias the gate-source junction?
A. positive-negative respectively
B. negative-positive respectively
C. forward-biased
D. any of the above
ANSWER: B
244. The voltage across the gate-source terminal of a FET that causes drain current ID equal to zero.
A. saturation voltage
B. threshold voltage
C. cut-off voltage
D. pinch-off voltage
ANSWER: D
245. The current that flows into the channel of a JFET when the gate-source voltage is zero.
A. drain-source saturation current
B. drain-source cut-off current
C. drain-source leakage current
D. drain-source pinch-off current
ANSWER: A
246. The graph of the drain current ID versus drain-source voltage VDS with VGS as the parameter.
A. transfer characteristic curve
B. output characteristic curve
C. input characteristic curve
D. current-voltage characteristic curve
ANSWER: D
247. In FET, the conduction path of the output is controlled by the electric field as its name implies. How does an electric field in FET established?
A. By the charges present at the gate due
to the reverse-biased junction.
B. By the application of reverse-biased
between the gate and drain.
C. By the charges produced due to the
applied potential between drain and source VDS.
D. By the charges present at each terminal
due to the applied potential. ANSWER: A
248. An early version of the field effect transistor in which limited control of current carriers near the surface of a semiconductor bar or film was obtained by an external electric field applied transversely.
A. fieldistor
B. JFET
C. IGFET
D. MOSFET
ANSWER: A
249. A FET in which the gate electrode consists of a pn junction
A. JFET
B. fieldistor
C. MOS-FET
D. IGFET
ANSWER: A
250. Which type of FET has the lowest input resistance?
A. JFET
B. MOS-FET
C. IGFET
D. VMOSFET
ANSWER: A
251. In order to increase further the input resistance of a FET, its gate is insulated. An example of this type is the
A. fieldistor
B. JFET
C. MOS-FET
D. A and B above
ANSWER: C
252. What is the insulator used in most MOS-FET?
A. CO2
B. SiO2
C. mica
D. plastic
ANSWER: B
253. An n-channel JFET has a drain-source saturation current IDSS = 10 mA and a gate-source pinch-off voltage Vp = -4 V. If the applied reverse gate-source voltage VGS = 2 V, calculate the drain current ID.
A. 2.5 mA
B. 5.0 mA
C. 10.0 mA
D. 22.5 mA
ANSWER: A
254. Base from Shockley’s equation of a JFET, what is the drain current when the applied voltage VGS is exactly equal to the pinch-off voltage Vp?
A. IDSS
B. maximum
C. minimum
D. zero
ANSWER: D
255. The transconductance of a JFET is defined as
A. dID/dVGS
B. dVGS/dID
C. dIDSS/dVGS
D. dID/dVp
ANSWER: A
256. A field-effect transistor in which the gate electrode is not a pn junction (as in the junction field-effect transistor) but a thin metal film insulated from the semiconductor channel by a thin oxide film.
A. MOSFET (enhancement type)
B. MOSFET (depletion type)
C. IGFET
D. all of the above
ANSWER: D
257. In MOSFET, it is the foundation upon which the device will be constructed and is formed from a silicon base
A. substrate
B. slab
C. source
D. base
ANSWER: A
258. A type of MOSFET wherein originally there is no channel between the drain and the source
A. depletion type
B. enhancement type
C. break type
D. insulated type
ANSWER: B
259. What type of MOSFET whose channel is originally thick but narrows as the proper gate bias is applied?
A. enhancement
B. depletion
C. transverse
D. all of the above
ANSWER: B
260. The amount of voltage needed at the gate-source terminal for an enhancement type MOSFET so that a channel can be formed for the current to flow.
A. “ON” voltage
B. pinch-off voltage
C. threshold voltage
D. trigger voltage
ANSWER: C
261. To switch off the depletion type MOSFET, the channel should be depleted. Depletion of the channel is done by applying enough voltage across the gate-source terminal. What do you call this voltage?
A. pinch-off voltage
B. trigger voltage
C. holding voltage
D. threshold voltage
ANSWER: A
262. The substrate of a MOSFET is usually connected internally to
A. source
B. gate
C. drain
D. channel
ANSWER: A
263. In an n-channel enhancement type MOSFET, the gate voltage should be ________ with respect to the source in order to produce or enhance a channel.
A. the same
B. positive
C. negative
D. either positive or negative
ANSWER: B
264. To deplete a channel from a p-channel IGFET
depletion type, the gate voltage should be ________ with respect to the source.
A. the same
B. positive
C. negative
D. either positive or negative as long as it
is greater ANSWER: B
265. The substrate used in a p-channel IGFET enhancement type
A. n -type material
B. n+ -type material
C. p -type material
D. p+ -type material
ANSWER: A
266. The base material of a MOSFET which extends as an additional terminal
A. source (S)
B. channel (C)
C. drain (D)
D. substrate (SS)
ANSWER: D
267. Which FET that has a substrate?
A. MOSFET enhancement type
B. IGFET
C. MOSFET depletion type
D. all of the above
ANSWER: D
268. What is the difference between a JFET and a MOSFET?
A. The gate of a MOSFET is insulated.
B. MOSFET uses a substrate in its
construction.
C. MOSFET can work in both forward and
reverse gate-source voltages.
D. all of the above
ANSWER: D
269. Calculate the transconductance of a p-channel MOSFET enhancement type if the gate-source voltage VGS = -8 V, threshold voltage VT = -4 and a constant k = 0.3 mA/V2.
A. 1.2 mS
B. 2.4 mS
C. 3.6 mS
D. 7.2 mS
ANSWER: B
270. One drawback of JFET devices is the strong dependence of the devices’ parameters on the channel geometry. Which parameter is an example of this?
A. drain saturation current (IDSS)
B. pinch-off voltage (VP)
C. transconductance (gm)
D. all of the above
ANSWER: D
271. JFET cutoff frequency is dependent on channel length by a factor of
A. 1/L
B. 1/L2
C. 1/L3
D. 1/L4
ANSWER: B
272. Which FET operates as close as BJT in terms of switching?
A. JFET
B. MOSFET depletion type
C. MOSFET enhancement type
D. IGFET
ANSWER: C
273. Generally, MOSFET has low power handling capability than BJT. To increase MOSFET power, the channel should be made
A. narrow and long
B. narrow and short
C. wide and long
D. wide and short
ANSWER: D
274. Which FET has a wide and short effective channel?
A. JFET
B. MOSFET
C. IGFET
D. V-MOSFET
ANSWER: D
275. A type of FET wherein the channel is formed in the vertical direction rather than horizontal
A. JFET
B. MOSFET
C. IGFET
D. V-MOSFET
ANSWER: D
276. Advantage or advantages of V-MOS over BJT
A. No stored charge and therefore faster in
switching action.
B. A negative temperature dependence of
output current which eliminates thermal runaway.
C. High input impedance and therefore
high current gain.
D. all of the above
ANSWER: D
277. In general, which of the transistors is particularly more useful in integrated-circuit (IC) chips?
A. BJTs
B. FETs
C. UJTs
D. all of the above
ANSWER: B
278. A monolithic semiconductor-amplifying device in which a high-impedance GATE electrode controls the flow of current carriers through a thin bar of semiconductor called the CHANNEL. Ohmic connections made to the ends of the channel constitute SOURCE and DRAIN electrodes.
A. BJT
B. UJT
C. FET
D. UPT
ANSWER: C
279. A junction field effect transistor has a drain saturation current of 10 mA and a pinch-off voltage of -4 V. Calculate the maximum transconductance.
A. 2.5 mS
B. 5.0 mS
C. 25.0 mS
D. 50.0 mS
ANSWER: B
280. In semiconductor application, which of the following statement is not true?
A. An ohmmeter test across the base-
collector terminal of a transistor should show low resistance in one polarity and high resistance in the opposite polarity.
B. A triac is a bidirectional device.
C. An ohmmeter test across a diode shows
low resistance in one polarity and high resistance in the opposite polarity.
D. An ohmmeter test across the base-
collector of a transistor should show low resistance for both polarities.
ANSWER: D
TEST4.
1. What do you call an amplifier which has an output current flowing during the whole input current cycle?
A. class AB amplifier
B. class B amplifier
C. class A amplifier
D. class C amplifier
ANSWER: C
2. Class A amplifier can be built from what transistor configuration?
A. common base
B. common emitter
C. common collector
D. all of the above
ANSWER: D
3. If a transistor amplifier provides a 360° output signal, it is classified as
A. class A
B. class B
C. class C
D. class D
ANSWER: A
4. An amplifier that delivers an output signal of 180° only.
A. class A
B. class B
C. class AB
D. class D
ANSWER: B
5. A class of amplifiers wherein the output signal swings more than 180° but less than 360°.
A. class A
B. class B
C. class C
D. class AB
ANSWER: D
6. What is the distinguishing feature of a class C amplifier?
A. Output is present for less than 180
degrees of the input signal cycle
B. Output is present for the entire signal
cycle
C. Output is present for exactly 180
degrees of the input signal cycle
D. Output is present for more than 180
degrees but less than 60 degrees of the input signal cycle
ANSWER: A
7. A full 360° sine-wave signal is applied as an input to an unknown class of amplifier, if the output delivers only a pulse of less than 180°, of what class does this amplifier belongs?
A. class AB
B. class B
C. class C
D. class D
ANSWER: C
8. Which class of amplifiers that is intended for pulse operation?
A. class B
B. class C
C. class D
D. class S
ANSWER: C
9. How do you classify an amplifier used to amplify either amplitude modulated (AM) or frequency modulated (FM) signals?
A. class C
B. class BC
C. class D
D. class S
ANSWER: D
10. Which class of amplifiers that has the highest efficiency?
A. class A
B. class B
C. class C
D. class D
ANSWER: D
11. What is the efficiency of a series-fed class A amplifier?
A. 25%
B. 50%
C. 78.5%
D. above 90%
ANSWER: A
12. A class A amplifier has an efficiency of only 25%, but this can be increased if the output is coupled with a transformer. Up to how much is its efficiency will reach due to coupling?
A. 36.5%
B. 50%
C. 68.5%
D. 78.5%
ANSWER: B
13. Class B amplifiers deliver an output signal of 180° and have a maximum efficiency of
A. 50%
B. 68.5%
C. 78.55
D. above 90%
ANSWER: C
14. Transistorized class C power amplifiers will usually have an efficiency of
A. 25%
B. 33%
C. 50%
D. 78.5%
ANSWER: B
15. For pulse-amplification, class D amplifier is mostly used. How efficient is a class D amplifier?
A. about 25% efficient
B. less efficient than class B
C. more efficient than class A but less
efficient than class B
D. its efficiency reaches over 90%
ANSWER: D
16. An amplifier of class AB means its output signal is between the output of class B and A, such that it varies from 180° (class B) to 360° (class A). How about its efficiency?
A. Efficiency of class AB is in between the
efficiency of class A and B, that is from 25% - 78.5%.
B. It is always as efficient as class A
(25%).
C. It is always as efficient as class B
(78.5%)
D. The efficiency of class AB is the average
of the efficiencies of both class A and class B (25% + 78.5%)/2 = 51.75%
ANSWER: A
17. Among the given amplifiers below, which is the most efficient?
A. class A (series-fed)
B. class A (transformer-coupled)
C. class A (directly-coupled)
D. class A (capacitor-coupled)
ANSWER: B
18. In order to have the best efficiency and stability, where at the loadline should a solid state power amplifier be operated?
A. Just below the saturation point
B. At 1.414 times the saturation point
C. Just above the saturation point
D. At the saturation point
ANSWER: A
19. In most transistor class A amplifiers, the quiescent point is set at
A. near saturation
B. near cutoff
C. below cutoff
D. at the center
ANSWER: D
20. For a class B amplifier, the operating point or Q-point is set at
A. the top of the load line
B. saturation
C. the center
D. cutoff
ANSWER: D
21. The Q-point for class A amplifier is at the active region, while for class B it is at cutoff region, how about for class AB?
A. it is slightly below saturation
B. it is slightly above cutoff
C. it is slightly above saturation
D. it is at the saturation region
ANSWER: B
22. Where does the Q-point of a class C amplifier positioned?
A. at saturation region
B. at active region
C. at cutoff region
D. below cutoff region
ANSWER: D
23. The Q-point of a class D amplifier can be set or positioned at what region in the load line?
A. below saturation
B. above cutoff
C. at cutoff
D. any of the above
ANSWER: D
24. Which of the amplifiers given below that is considered as non-linear?
A. class A
B. class B
C. class AB
D. class C
ANSWER: D
25. Which amplifiers can be used for linear amplification?
A. class A
B. class B
C. class C
D. class A or B
ANSWER: D
26. What do you call an amplifier that is biased to class C but modulates over the same portion of the curve as if it were biased to class B?
A. class S
B. class D
C. class AB
D. class BC
ANSWER: D
27. Two class B amplifiers connected such that one amplifies the positive cycle and the other amplifies the remaining negative cycle. Both output signals are then coupled by a transformer to the load.
A. transformer-coupled push –pull
amplifier
B. complementary-symmetry amplifier
C. quasi-complementary push-pull
amplifier
D. transformer-coupled class A amplifier
ANSWER: A
28. A push-pull amplifier that uses npn and pnp transistors to amplify the positive and negative cycles respectively.
A. transformer-coupled push –pull
amplifier
B. complementary-symmetry amplifier
C. quasi-complementary push-pull
amplifier
D. transformer-coupled class A amplifier
ANSWER: B
29. A push-pull amplifier that uses either npn or pnp as its final stage. The circuit configuration looks like the complementary-symmetry.
A. transformer-coupled push –pull
amplifier
B. complementary-symmetry amplifier
C. quasi-complementary push-pull
amplifier
D. feed-back pair amplifier
ANSWER: C
30. Amplifiers conversion efficiency are calculated using what formula?
A. ac-power/dc-power
B. ac-power/dissipated power
C. dc-power/ac-power
D. A or B are correct
ANSWER: D
31. Basically, which class of amplifiers has the least
distortion?
A. class A
B. class B
C. class C
D. class D
ANSWER: A
32. A type of distortion wherein the output signal does not have the desired linear relation to the input.
A. linear distortion
B. nonlinear distortion
C. cross-over distortion
D. all of the above
ANSWER: B
33. Distortion that is due to the inability of an amplifier to amplify equally well all the frequencies present at the input signal.
A. nonlinear distortion
B. amplitude distortion
C. harmonic distortion
D. cross-over distortion
ANSWER: B
34. A nonlinear distortion in which the output consists of undesired harmonic frequencies of the input signal.
A. amplitude distortion
B. frequency distortion
C. cross-over distortion
D. harmonic distortion
ANSWER: D
35. Calculate the 2nd harmonic distortion for an output signal having a fundamental amplitude of 3V and a 2nd harmonic amplitude of 0.3V.
A. 1.0%
B. 10%
C. 23.33%
D. 43.33%
ANSWER: B
36. An amplifier has the following percent harmonic distortions; D2=10%, D3=5% and D4=1%. What is the amplifier % THD?
A. 5.33%
B. 11.22%
C. 16.0%
D. 22.11%
ANSWER: B
37. Which of the following refers to the gain of a circuit?
A. Input quantity of an amplifier divided by
the output quantity.
B. The difference between the input
voltage and the output voltage of a circuit.
C. The ratio of the output quantity to input
quantity of an amplifier.
D. The total increase in output quality over
the input quantity of an amplifier. ANSWER: C
38. The overall gain of an amplifier in cascade is
A. the sum
B. the average of each
C. the product
D. 100% the sum
ANSWER: C
39. If three amplifiers with a gain of 8 each are in cascade, how much is the overall gain?
A. 72
B. 24
C. 512
D. 8
ANSWER: C
40. A multistage transistor amplifier arranged in a conventional series manner, the output of one stage is forward-coupled to the next stage.
A. cascaded amplifier
B. cascoded amplifier
C. darlington configuration
D. feed-back pair configuration
ANSWER: A
41. A direct-coupled two-stage transistor configuration wherein the output of the firs transistor is directly coupled and amplified by the second transistor. This configuration gives a very high current gain.
A. cascade configuration
B. cascode configuration
C. darlington configuration
D. feed-back pair
ANSWER: C
42. A two-stage transistor amplifier in which the output collector of the first stage provides input to the emitter of the second stage. The final output is then taken from the collector of the second stage.
A. cascade configuration
B. cascode configuration
C. quasi-complementary
D. complementary amplifier
ANSWER: B
43. Famous transistor amplifier configuration designed to eliminate the so called Miller effect.
A. cascode amplifier
B. darlington amplifier
C. differential amplifier
D. complementary-symmetry
ANSWER: A
44. What are the transistor configurations used in a cascade amplifier?
A. common-base and common-emitter
B. common-base and common-collector
C. common-collector and common-emitter
D. common-emitter and common-base
ANSWER: D
45. Transistor configuration known to have a super-beta (β2).
A. cascade
B. cascode
C. darlington
D. differential
ANSWER: C
46. What is the approximate threshold voltage between the base-emitter junction of a silicon darlington transistor?
A. 0.3 V
B. 0.6 V
C. 1.6 V
D. 3.0 V
ANSWER: C
47. Transistor arrangement that operates like a darlington but uses a combination of pnp and npn transistors instead of both npn.
A. differential
B. common
C. cascode
D. feedback pair
ANSWER: D
48. An amplifier basically constructed from two transistors and whose output is proportional to the difference between the voltages applied to its two inputs.
A. differential amplifier
B. cascode amplifier
C. complementary amplifier
D. quasi-complementary amplifier
ANSWER: A
49. An amplifier having high direct-current stability and high immunity to oscillation, this is initially used to perform analog-computer functions such as summing and integrating.
A. operational amplifier (op-amp)
B. parametric amplifier (par-amp)
C. instrumentation amplifier
D. DC-amplifier
ANSWER: A
50. One of the most versatile and widely used electronic device in linear applications.
A. SCR
B. FET
C. UJT
D. op-amp
ANSWER: D
51. It is a very high-gain differential amplifier with very high input impedance and very low output impedance.
A. par-amp
B. op-amp
C. differential amp
D. complementary amp
ANSWER: B
52. What are the possible applications of operational amplifiers (op-amps)?
A. ac and dc-amplifiers
B. oscillators and signal conditioning
C. voltage-level detectors and comparators
D. all of the above
ANSWER: D
53. An operational amplifier must have at least how many usable terminals?
A. 3 terminals
B. 5 terminals
C. 8 terminals
D. 14 terminals
ANSWER: B
54. The circuit at the input stage of operational amplifiers
A. differential amplifier
B. cascaded amplifier
C. current mirror
D. complementary amplifier
ANSWER: A
55. An amplifier whose output is proportional to the difference between the voltages applied to its two inputs.
A. differential amplifier
B. differencing
C. delta amp
D. cascode-amp
ANSWER: A
56. In op-amps functional block diagram, what follows the differential amplifier?
A. cascode-amplifier
B. complementary amplifier
C. level shifter
D. high gain amplifier
ANSWER: D
57. A good op-amp has a
A. very high input resistance
B. very low input resistance
C. very high output resistance
D. very low CMRR
ANSWER: A
58. Ideally, op-amps have infinite input resistance and ________ output resistance.
A. infinite
B. zero
C. variable
D. a highly stabilized
ANSWER: B
59. How does the input of an op-amp made high?
A. by using super beta transistor at the
input differential stage
B. by using FETs at the input differential
stage
C. by connecting a very high resistance in
series with the input differential stage
D. A and B above
ANSWER: D
60. What type of amplifier commonly used at the output stage of op-amps?
A. differential amplifier
B. cascade-amplifier
C. complementary amplifier
D. darlington stage amplifier
ANSWER: C
61. The transistor configuration used at the output complementary stage of most op-amps
A. cascode configuration
B. common emitter
C. common collector
D. common base
ANSWER: C
62. Why do most op-amps use a common collector at the output stage?
A. to have a higher output power
B. to have a better frequency response
C. to have a low harmonic distortion
D. to have a very low output resistance
ANSWER: D
63. The stage followed by the output complementary in op-amps functional block diagram.
A. level shifter
B. phase shifter
C. current mirror
D. polarizer
ANSWER: A
64. What is the purpose of a level shifter in op-amps?
A. to set and/or adjust the output voltage
to zero when the input signal is zero
B. to set and/or adjust the input offset
voltage to zero
C. to shift the input offset current to zero
D. all of the above
ANSWER: A
65. Primarily, op-amps are operated with bipolar power supply, however, we can also use single polarity power supply by
A. generating a reference voltage above
ground.
B. “floating” the negative supply terminal
(V-) of the op-amp.
C. simply connecting the negative supply
terminal (V-) of the op-amp to ground.
D. isolating the negative supply terminal
(V-) by a capacitor. ANSWER: A
66. Op-amps have two input terminals namely, the inverting (-) and non-inverting (+) inputs. What is the significance of its name?
A. If a sine-wave is applied to the inverting
(-) input, the output will be inverted or shifted by 180°, while if applied to the non-inverting (+) there will be no phase shift at the output.
B. If pulses are applied to the inverting (-)
input, the positive pulse becomes negative at the output and vice versa, while if applied at the non-inverting (+) there will be no reversal of the pulse at the output.
C. In dc amplifier applications, increasing
input at the inverting (-) terminal causes the output to decrease and vice versa, while at the non-inverting (+)
input, the output magnitude goes with the input.
D. all of these are correct
ANSWER: D
67. When the same signal is applied to both inverting and non-inverting input terminals of an ideal op-amp, the output voltage would be
A. zero (0) V
B. +VSAT
C. –VSAT
D. offset voltage
ANSWER: A
68. The operating mode of an op-amp, when both inputs are tied together or when the input signal is common to both inputs.
A. differential mode
B. rejection mode
C. double-ended mode
D. common mode
ANSWER: D
69. What do you call of the gain of an op-amp if operated in common mode input?
A. differential gain
B. common gain
C. double-ended gain
D. rejection gain
ANSWER: B
70. When one input of the op-amp is connected to ground and the other is to the signal source, its operation is called
A. single-ended output
B. double-ended output
C. single-ended input
D. double-ended input
ANSWER: C
71. If op-amps are operated in differential mode, its gain is technically termed as
A. common-mode differential gain
B. differential gain
C. open-loop gain
D. closed-loop gain
ANSWER: B
72. In op-amps, which gain is the highest?
A. common-mode gain
B. differential gain
C. closed-loop gain
D. open-loop gain
ANSWER: D
73. The ratio of the differential gain and common gain of an op-amp
A. differential-common mode ratio
B. common-mode ratio
C. differential-mode rejection ratio
D. common-mode rejection ratio
ANSWER: D
74. An operational amplifier has a common-mode voltage gain of 10 and a differential-mode voltage gain of 20,000, calculate its common-mode rejection ratio (CMRR).
A. 200
B. 2,000
C. 20,000
D. 200,000
ANSWER: B
75. Calculate the CMRR of an op-amp having a common-mode gain of 10 and a differential-mode gain of 100,000.
A. 1000 dB
B. 100 dB
C. 80 dB
D. 40 dB
ANSWER: C
76. The non-inverting and inverting inputs of an op-amp have an input voltage of 1.5 mV and 1.0 mV, respectively. If the op-amp has a common-mode voltage gain of 10 and a differential-mode gain of 10,000, what is its output voltage?
A. 5.0 V
B. 5.0125 mV
C. 5.0125 V
D. 25.0125 V
ANSWER: C
77. What is the maximum output voltage swing of an op-amp?
A. +V to -V (supply voltage)
B. +VSAT to -VSAT
C. +½V to -½V
D. depends on the input signal
ANSWER: B
78. The µA741 op-amp has a CMRR of 90dB and a differential-mode voltage amplification of 200,000.What is the op-amp’s common-mode voltage gain?
A. 31,622.778
B. 632.40
C. 6.324
D. 0.158
ANSWER: C
79. The current needed at the input of an op-amp to
operate it normally
A. input bias current
B. input offset current
C. input threshold current
D. input holding current
ANSWER: A
80. Ideal op-amp requires no input current, but real op-amp needs a very small input current called input bias current. At both inputs, the bias currents have a slight difference. What do you call this difference?
A. differential input current
B. differential bias
C. input offset difference
D. input offset current
ANSWER: D
81. The change in input offset current due to temperature change
A. delta input offset current
B. slew rate
C. input offset current drift
D. PSRR
ANSWER: C
82. The reason why a slight difference between the input bias current occurs in op-amps is due to the unsymmetrical circuit component parameters. This unsymmetrical condition also produces a difference in input voltage called what?
A. drift voltage
B. differential voltage
C. input offset voltage
D. input threshold voltage
ANSWER: C
83. As electronic circuit operates, its operating temperature changes which causes device parameters to change. In op-amps, what do you call the change in input offset voltage due to the change in temperature?
A. input differential drift
B. input offset voltage drift
C. slew rate
D. PSRR
ANSWER: B
84. It is known through experiment that the input bias currents at the non-inverting (IB+) and inverting (IB-) inputs of a certain op-amp is 100 nA and 80 nA, respectively. Determine the op-amp’s input offset current.
A. -20 nA
B. 20 nA
C. 90 nA
D. 180 nA
ANSWER: B
85. Ideally, the output voltage of an op-amp is zero when there is no input signal, however, in practical circuits, a small output voltage appears, this voltage is known as
A. minimum output voltage
B. pinch-off voltage
C. output offset voltage
D. saturation voltage
ANSWER: C
86. The output offset voltage of an op-amp is (are) due to
A. input offset current
B. input offset voltage
C. voltage and current drift
D. A and B above
ANSWER: D
87. Calculate the output offset voltage of an inverting amplifier using op-amp with an input offset current of 10 nA. The circuit is having an input resistance of 10 kΩ and a feedback resistance of 100 kΩ.
A. 0.1 mV
B. 1.0 mV
C. 10.0 mV
D. 100.0 mV
ANSWER: B
88. An op-amp inverting amplifier uses a feedback resistor of 100 kΩ and input resistor of 10 kΩ. If the op-amps input offset voltage is 2.0 mV, approximate the amplifier output offset voltage due to this input offset voltage.
A. 10 mV
B. 11 mV
C. 20 mV
D. 22 mV
ANSWER: D
89. The output offset voltage of an op-amp is due to the input offset current and voltage. If 1 mV is due to the input offset current and 22 mV due to the input offset voltage, what is the total output offset voltage of the op-amp?
A. 11.5 mV
B. 22 mV
C. 23 mV
D. 45 mV
ANSWER: C
90. How will you minimize the output offset voltage due to the input offset current of an op-amp?
A. by installing a bias-current-
compensating resistor
B. by increasing the value of the feedback
resistor
C. by decreasing the value of the input
resistor
D. B and C above
ANSWER: A
91. What is a bias-current compensating resistor in op-amp circuits?
A. A resistor used to reduce the undesired
output offset voltage due to the input offset current.
B. A resistor connected between the non-
inverting terminal and ground.
C. A resistor used to balance both input
bias currents and therefore eliminates the input offset current.
D. all of these
ANSWER: D
92. The approximate value of the bias-current compensating resistor in op-amp circuits is
A. equal to the feedback resistor
B. equal to the input resistor
C. equal to the series combination of the
input and feedback resistors
D. equal to the parallel combination of the
input and feedback resistors ANSWER: D
93. In op-amp analysis, the input offset voltage is represented by
A. a battery
B. a signal generator
C. Thevenin’s voltage source
D. Norton’s current source
ANSWER: A
94. The battery representing the input offset voltage in op-amp circuit analysis is connected where?
A. between the inverting and ground
terminal
B. between the non-inverting and ground
terminal
C. between the inverting and non-inverting
terminal
D. either B and C above
ANSWER: B
95. What is the effect of the input offset voltage to the output voltage if the op-amp has no feedback element?
A. causes the output to be always at cutoff
B. causes the output to saturate towards
positive
C. causes the output to saturate towards
negative
D. causes the output to saturate either
towards positive or negative ANSWER: D
96. How can we minimize the effect of the input offset current and input offset voltage at the output offset voltage?
A. by making the feedback resistance
small
B. by making the feedback resistance large
C. by making the input resistance small
D. by making the input resistance large
ANSWER: A
97. An op-amp is wired as an inverting amplifier with an input and feedback resistances of 1 kΩ and 100 kΩ, respectively. When the input signal is set to zero, the output was found to have an offset voltage of 101 mV. Calculate the input offset voltage.
A. 0.01 mV
B. 0.1 mV
C. 1.0 mV
D. 10.0 mV
ANSWER: C
98. What is the most effective way of minimizing the output offset voltage of an op-amp?
A. by reducing the value of the feedback
resistor
B. by increasing the value of the input
resistor
C. by a capacitor-compensation technique
D. by properly using and adjusting the
offset-null terminals ANSWER: D
99. What cause(s) the well-adjusted output offset voltage of op-amps to change?
A. change in operating temperature
B. component aging
C. variations in supply voltage
D. all of the above
ANSWER: D
100. Which op-amp parameter(s) that normally affects its small signal dc-amplification performance?
A. input bias current
B. input offset voltage
C. input offset current
D. all of the above
ANSWER: D
101. Op-amp parameter(s) that is important in large signal dc-amplification.
A. input offset voltage
B. input offset current
C. slew rate
D. all of the above
ANSWER: C
102. In large signal dc-amplifiers using op-amp, which parameter has the least effect on its performance?
A. drift
B. slew rate
C. input offset voltage
D. input offset current
ANSWER: A
103. For ac-amplifiers using op-amps what parameters can affect its performance.
A. input offset current and voltage
B. input bias current and voltage
C. drift and slew rate
D. slew rate and frequency response
ANSWER: D
104. If an op-amp is used to amplify small ac-signals, what parameter you should greatly consider to ensure better performance?
A. input bias current
B. drift
C. frequency response
D. slew rate
ANSWER: C
105. What do we mean by internally compensated op-amps?
A. Op-amps with internal frequency
compensation capacitor to prevent oscillation.
B. Op-amps with an internal compensating
resistor to make the output offset voltage zero.
C. Op-amps with internal coupling
capacitor to block dc-voltages and allows ac-voltages to pass.
D. Op-amps with internal active
components to make its gain constant at the entire operating frequency.
ANSWER: A
106. The frequency at which the open-loop gain of
an op-amp is 0.707 times its value at very low frequency
A. threshold frequency
B. break frequency
C. minimum frequency
D. operating frequency
ANSWER: B
107. What will happen to the voltage gain of op-amp when its operating frequency is increased?
A. also increases
B. increases exponentially
C. will decrease
D. decreases exponentially
ANSWER: C
108. The reduction of op-amps gain due to increasing operating frequency.
A. Cutoff
B. roll-off
C. diminishing factor
D. reduction step
ANSWER: B
109. What do we mean by a 20 dB/decade roll-off?
A. a gain reduction by a factor of 10 per
decade
B. a gain reduction by a factor of 20 per
decade
C. a gain reduction by a factor of 10 per
10 Hz increased in frequency
D. a gain reduction by a factor of 20 per
10 Hz increased in frequency ANSWER: A
110. A reduction of op-amp’s voltage gain by a factor of two each time the frequency doubles.
A. 2 dB/octave
B. 2 dB/decade
C. 6 dB/octave
D. 6 dB/decade
ANSWER: C
111. Frequency at which the voltage gain of op-amp reduces to unity.
A. unity-gain frequency
B. cutoff frequency
C. bandwidth point
D. unity-gain bandwidth product
ANSWER: D
112. The low and high cutoff frequencies of an amplifier is also called
A. corner frequencies
B. 0.707 frequencies
C. 3-dB frequencies
D. all of these are correct
ANSWER: D
113. Calculate the cutoff frequency (fc)of an op-amp having a unity-gain bandwidth product B1 = 1 MHz and a open-loop voltage gain AOL = 100,000.
A. 10 Hz
B. 20 Hz
C. 100 Hz
D. 200 Hz
ANSWER: A
114. An op-amp has a specified transient response rise time of 0.3 µs, calculate its unity-gain bandwidth.
A. 0.857 MHz
B. 1.0 MHz
C. 1.167 MHz
D. 2.334 MHz
ANSWER: C
115. Rise time is defined as the time required for the output voltage to rise from _______ to ________ of its final value.
A. 0% - 100%
B. 1% - 99%
C. 5% - 95%
D. 10% - 90%
ANSWER: D
116. The maximum output voltage rate of change of an op-amp.
A. rise time
B. maximum voltage swing
C. differential rate
D. slew rate
ANSWER: D
117. Factor(s) or parameter(s) that determine(s) the op-amps maximum operating temperature
A. PSRR
B. slew rate
C. unity-gain bandwidth product
D. B and C above
ANSWER: D
118. What is the maximum signal frequency that can be used in an op-amp having a specified
slew rate of 0.5 V/µsec? The maximum output voltage desired is 5 V.
A. 16 kHz
B. 32 kHz
C. 100 kHz
D. 1 MHz
ANSWER: A
119. What must be the slew rate of an op-amp to be used in order to provide an undistorted output voltage of .10 V ac a frequency of 100,000 rad/sec?
A. 0.1 V/µsec
B. 0.5 V/µsec
C. 1.0 V/µsec
D. 6.28 V/µsec
ANSWER: C
120. When an op-amp is used as a comparator, the output voltage would be +VSAT if
A. V+ > V-
B. V- > V+
C. V- = V+
D. V- and V+ are both zero
ANSWER: A
121. Two comparators using op-amps, configured such that it can detect voltage levels within a certain range of values rather than simply comparing whether a voltage is above or below a certain reference.
A. analog comparator
B. regenerative comparator
C. parallel comparator
D. window comparator
ANSWER: D
122. What gain is significant when an op-amp is used as a voltage comparator?
A. open-loop gain
B. common gain
C. differential closed loop gain
D. closed loop gain
ANSWER: A
123. An op-amp zero-crossing detector without hysteresis,
A. uses a resistor as its feedback element
B. uses a capacitor as its feedback
element
C. uses an inductor as its feedback
element
D. has no feedback
ANSWER: D
124. The feedback element of a differentiator constructed from op-amp is
A. a resistor
B. an inductor
C. a capacitor
D. an RC network
ANSWER: A
125. An active integrator uses an op-amp, what is its feedback element?
A. Resistor
B. capacitor
C. inductor
D. RC network
ANSWER: B
126. The voltage gain of an op-amp voltage follower.
A. unity
B. Rf/Ri
C. 1 + Rf/Ri
D. depends on the type of op-amp
ANSWER: A
127. Calculate the closed-loop voltage gain of an inverting amplifier having a feedback and an input resistance of 100 kΩ and 10 kΩ, respectively.
A. 10
B. 11
C. 100
D. 110
ANSWER: A
128. The gain of an inverting amplifier is determined by the ratio of the feedback and input resistors (Rf/Ri), meaning we can select any value of resistors as long as its ratio is the same. What op-amp parameter that helps us determine the appropriate values of these resistors?
A. CMRR
B. PSRR
C. SR
D. input bias current
ANSWER: D
129. What is the noise gain of op-amps?
A. equal to the open loop gain
B. Rf/Ri
C. 1 + Rf/Ri
D. equal to the common gain
ANSWER: C
130. A unity-gain summing amplifier has three inputs, V1 = 1.0 mV, V2 = 1.5 mV, and V3 = 2.5 mV, calculate the total output voltage.
A. 2.5 mV
B. 3.5 mV
C. 4.0 mV
D. 5.0 mV
ANSWER: D
131. The random voltage at the output of an op-amp which could occupy the entire bandwidth.
A. noise
B. hash
C. interference
D. all of the above
ANSWER: D
132. Which of the following of the resistor combinations that provides lesser noise in op-amp circuits?
A. Make both the feedback and input
resistances as large as possible
B. Make the feedback as large as possible,
while the input as low as possible.
C. Make the feedback as low as possible,
while the input as large as possible.
D. Make the feedback and input
resistances as small as possible. ANSWER: D
133. In most ac-amplifiers using op-amps, the feedback resistor is shunted with a very small capacitance, what is its purpose?
A. to prevent oscillation
B. to improve stability
C. to minimize high frequency noise
D. to compensate for high frequency loss
ANSWER: C
134. Approximate the noise gain of an inverting adder using op-amps if it has five inputs.
A. unity (1)
B. two (2)
C. four (4)
D. six (6)
ANSWER: D
135. Op-amps with internal frequency compensation are very stable with respect to signal frequencies. However, the trade-off for frequency stability is (are)
A. limited small-signal bandwidth
B. slow slew rate
C. limited open-loop frequency response
D. all of these
ANSWER: D
136. What do we mean by externally compensated op-amps?
A. op-amps with frequency-compensation
terminals
B. op-amps with provision to externally
compensate for frequency stability
C. op-amps whose gain is externally
compensated
D. A and B above
ANSWER: D
137. What is true about the external frequency-compensation capacitor?
A. the higher its value, the wider is its
bandwidth
B. the lower its value, the wider is its
bandwidth
C. the higher its value, the faster its slew
rate
D. A and C above
ANSWER: B
138. Typical value of the external frequency-compensating capacitor of op-amps.
A. 3 - 30 nF
B. 30 - 300 nF
C. 0.3 - 3.0 µF
D. 3.0 - 30 µF
ANSWER: D
139. What do we mean by a general-purpose op-amps?
A. op-amps with limited unity-gain
bandwidth up to approximately 1 MHz
B. op-amps with slew rate about 0.5
V/µsec
C. op-amps that has unlimited application
D. A and B above
ANSWER: D
140. Op-amps designed to operate at high slew rate, about 2000 V/µsec and at high frequencies, more than 50 MHz.
A. general purpose op-amps
B. high power op-amps
C. high-stability op-amps
D. high-frequency, high-slew rate op-amps
ANSWER: D
141. Generally, where does hybrid op-amps found its application?
A. for high-output voltage
B. for high-output current
C. for high-frequency
D. A and B above
ANSWER: D
142. The magnitude of the op-amps input offset voltage before it can be classified as a low-input offset voltage op-amp
A. 0.2 mV
B. 2.0 mV
C. 2.5 mV
D. 5.0 mV
ANSWER: A
143. Op-amps whose internal transistor biasing can be controlled externally are categorize as
A. general purpose op-amps
B. programmable op-amps
C. variable op-amps
D. externally compensated op-amps
ANSWER: B
144. What op-amp parameter(s) that can be governed by the bias control in a programmable op-amp?
A. open-loop gain and slew rate
B. unity-gain bandwidth
C. input bias current
D. all of the above
ANSWER: D
145. The most popular op-amp packages are the metal can, 8-pin DIP, and the SMT. Which of these corresponds to TO-99?
A. metal can
B. 8-pin DIP
C. SMT
D. all of the above
ANSWER: A
146. Dual-in-line or DIL package is designated as
A. TO-99
B. TO-91
C. TO-116
D. TO-220
ANSWER: C
147. For high density ICs involving many op-amps, what packaging is suitable?
A. metal can
B. 14-pin DIL
C. SMT
D. flat-pack
ANSWER: C
148. Example(s) of surface-mounted technology (SMT) devices.
A. PLCCs
B. SOICs
C. LCCCs
D. all of the above
ANSWER: D
149. Which condition must exist for a circuit to oscillate?
A. It must have a negative feedback
sufficient to cancel the input
B. It must have a gain of less than 1
C. It must have a positive feedback
sufficient to overcome losses
D. It must be neutralized
ANSWER: C
150. Which of the following is not an essential part of an oscillator?
A. Source of energy that supply the losses
in tank circuit.
B. A resistor IC combination circuit.
C. Resonant circuit consist of inductance
and capacitance.
D. Regenerative feedback circuit.
ANSWER: B
151. Circuits that produces alternating or pulsating current or voltage.
A. Damper
B. Generator
C. oscillator
D. mixer
ANSWER: C
152. What do you call the oscillator circuit that uses a tapped coli in the tuned circuit?
A. Pierce
B. Colpitts
C. Hartley
D. Ultraudion
ANSWER: C
153. What determines the resonant frequency of a crystal?
A. external components
B. the temperature of the crystal
C. the size and thickness of the crystal
material
D. the hermitic seal
ANSWER: C
154. Type of oscillator whose frequency is dependent on the charge and discharge of RC networks.
A. Hartley oscillator
B. Copitts oscillator
C. Relaxation oscillator
D. Klystron oscillator
ANSWER: C
155. A microwave oscillator
A. Hartley oscillator
B. Copitts oscillator
C. Relaxation oscillator
D. Klystron oscillator
ANSWER: D
156. A self-excited oscillator in which the tank is divided into input and feedback portions by a capacitive voltage divider.
A. Hartley capacitor
B. Copitts oscillator
C. Relaxation oscillator
D. Klystron oscillator
ANSWER: B
157. A self-excited oscillator in which the tank is divided into input and feedback portions by an inductive voltage divider or a tapped coil.
A. Hartley oscillator
B. Copitts oscillator
C. Relaxation oscillator
D. Klystron oscillator
ANSWER: A
158. A circuit usually containing two transistors or tubes in an RC-coupled amplifier, the two active devices switch each other alternately on and off.
A. Multivibrator
B. Signal generator
C. Oscillator
D. Thyristor
ANSWER: A
159. A multivibrator that generates one output pulse for each input trigger pulse.
A. monostable
B. astable
C. bistable
D. tristate
ANSWER: A
160. Monostable multivibrator is also known as
A. one shot
B. single shot
C. direct shot
D. one shot or single shot
ANSWER: D
161. What determines the pulse time in a monostable multivibrator?
A. resistor combinations
B. capacitor combinations
C. inductor combinations
D. resistor and capacitor combinations
ANSWER: D
162. A multivibrator having two stable state
A. monostable
B. bistable
C. astable
D. unstable
ANSWER: B
163. Is also known as Eccles/Jordan circuit
A. Monostable multivibrator
B. bistable multivibrator
C. astable multivibrator
D. unstable multivibrator
ANSWER: B
164. Flip-flop is actually a _______ multivibrator.
A. Monostable
B. bistable
C. astable
D. unstable
ANSWER: B
165. Considered as a free-running multivibrator
A. monostable
B. bistable
C. astable
D. unstable
ANSWER: C
TEST5.
1. A device that transforms chemical energy into electrical energy
A. secondary battery
B. cell
C. battery
D. primary battery
ANSWER: B
2. A device that is capable of converting chemical energy into electrical energy
A. generator
B. battery
C. converter
D. cell
ANSWER: D
3. A secondary cell whose active positive plate consists of nickel hydroxide, and active negative-plate material is powdered iron oxide mixed with cadmium. Its typical output when fully charged is VO = 1.2V
A. Leclanche cell
B. dry cell
C. Edison cell
D. lead-acid cell
ANSWER: C
4. If a cell can be charged after it is depleted, it is considered as
A. a secondary cell
B. a storage cell
C. an accumulator
D. all of the above
ANSWER: D
5. What type of cell that cannot be recharged which cannot restore chemical reaction?
A. nickel-cadmium cell
B. secondary cell
C. primary cell
D. lead-acid wet cell
ANSWER: C
6. A cell whose chemical reaction is not reversible
A. primary cell
B. secondary cell
C. rechargeable cell
D. solar cell
ANSWER: A
7. A voltage source in a single container made from one or more cells combines in series, parallel, or series-parallel.
A. photoelectric
B. thermocouple
C. battery
D. piezo-electric
ANSWER: C
8. A battery means
A. cells connected in series
B. cells connected in parallel
C. cells connected in series-parallel
D. all of the above
ANSWER: D
9. A battery is used to
A. supply a steady dc voltage
B. supply an unstable dc voltage
C. supply an ac voltage
D. supply an ac/dc voltage
ANSWER: A
10. In a dry cell, what will happen to the internal resistance as it aged?
A. decreases
B. increases
C. remains constant
D. decreases or increases, depends on the
chemical composition ANSWER: B
11. The maximum current a cell can deliver through a 0.01 ohm load during testing
A. flash current
B. surge current
C. ideal current
D. full-load current
ANSWER: A
12. In batteries, the material used to insulate the positive plates from negative plates are technically called
A. insulator
B. break-point
C. coupler
D. separator
ANSWER: D
13. How long will a battery need to operate a 240 Watts equipment, whose capacity is 100Ah and 24 volts rating?
A. 5 hrs
B. 10 hrs
C. 1 hr
D. 0.10 hr
ANSWER: B
14. A battery is rated 20 A-hr and is delivering a current of 2A. How long does it last?
A. 1 hr
B. 5 hrs
C. 8 hrs
D. 10 hrs
ANSWER: D
15. A primary cell with carbon and zinc as its positive and negative electrodes respectively, and an electrolyte of either a gel or paste. This is commonly known as dry cell.
A. Leclanche cell
B. Edison cell
C. storage cell
D. solar cell
ANSWER: A
16. Find the output of a four (4) lead acid cells.
A. 3.2 V
B. 8.4 V
C. 5.8 V
D. 12 V
ANSWER: B
17. Silver-cadmium cell has a nominal open-circuit voltage of
A. 1.05 V
B. 1.5 V
C. 2.1 V
D. 2.2 V
ANSWER: A
18. Output of six carbon-zinc cells connected in series
A. 3 V
B. 6 V
C. 6.6 V
D. 9 V
ANSWER: D
19. The flat 9-V battery, has how many cells in series?
A. 3
B. 4
C. 6
D. 9
ANSWER: C
20. Output of automotive battery with six lead-acid cells in series
A. 6V
B. 12V
C. 24V
D. 48V
ANSWER: B
21. Substance, which generates a voltage when exposed to light.
A. generating substance
B. photovoltaic material
C. thermoelectric generator
D. hydroelectric generator
ANSWER: B
22. A cell whose voltage is generated as a function of light
A. photovoltaic cell
B. thermoelectric cell
C. photodiode
D. LED
ANSWER: A
23. Substance used in photovoltaic cells
A. Silicon
B. Selenium
C. Germanium
D. All of these
ANSWER: D
24. A junction between two conductors that exhibits electrical characteristics under condition of changing temperature
A. pn junction
B. photojunction
C. thermoelectric junction
D. hydroelectric junction
ANSWER: C
25. Electricity that is generated due to heat, as in thermocouple.
A. thermodynamics
B. thermojunction
C. electric heater
D. thermoelectricity
ANSWER: D
26. The source of mechanical power to turn the rotors of alternators, large and small, A.C. and D.C.
A. prime contactor
B. primer
C. prime mover
D. prime user
ANSWER: C
27. Electrical machines refer to machines that convert ________
A. mechanical to electrical energy
B. electrical to mechanical energy
C. electrical energy of one form to
electrical energy of another form
D. all of the above
ANSWER: D
28. Electrical machines that convert mechanical energy to electrical energy.
A. generators
B. motors
C. cycloconverters
D. frequency converters
ANSWER: A
29. Electrical machine that converts ac voltage to dc voltage, or vice versa.
A. generator
B. motor
C. rotary converter
D. frequency converter
ANSWER: C
30. Electrical machine that changes ac voltage at one frequency to another ac voltage at another frequency.
A. generator
B. motor
C. rotary converter
D. frequency converter
ANSWER: D
31. It consist of a single coil rotated in a magnetic field and produces an A.C. voltage.
A. field winding
B. armature
C. commutator
D. elementary generator
ANSWER: D
32. Generation of voltage in a generator can only happen when?
A. there is a rotary conductor
B. there is a magnetic field in a conductor
C. there is a relative motion between
conducting wires and magnetic lines of force
D. there is a relative motion between a
conductor and electric field ANSWER: C
33. Two essential parts in rotating generators
A. electro/permanent magnets and
armature winding
B. electromagnets or permanent magnets
and commutator
C. commutator and armature winding
D. brushes and commutator
ANSWER: A
34. In electrical machines, what do you call the set of conductors wound on laminated cores of good magnetic permeability?
A. armature core
B. armature winding
C. rotary winding
D. rotary core
ANSWER: B
35. In dc generator, what converts the alternating emf to DC?
A. armature
B. commutator
C. diode
D. alternator
ANSWER: B
36. Generally, in dc generators
A. The armature winding is rotated with
respect to a stationary magnetic field produced by electromagnets or permanent magnets.
B. The electromagnets or permanent
magnets (magnetic fields) are rotated with respect to the stationary armature winding.
C. Current is sent into the armature
winding; or the armature winding is usually placed in a stationary laminated iron core and the rotating element may or may not be a set of magnet poles, it depends on the type of motor.
D. The armature winding is supplied with
current; or the armature is placed inside a set of radially supported magnetic poles.
ANSWER: A
37. In electrical machines, what type of voltage is generated at the armature winding?
A. dc
B. pulsating dc
C. ac
D. ac or dc depending on the type of
machine ANSWER: C
38. Generally in ac generators
A. The armature winding is rotated by a
stationary magnetic field produced by electromagnets or permanent magnets.
B. Current is sent into the armature
winding; or the armature winding is usually placed in a stationary laminated iron core and the rotating element may or may not be a set of magnet poles, it depends on the type of motor.
C. The electromagnets or permanent
magnets (magnetic fields) are rotated with respect to the stationary armature winding.
D. The armature winding is supplied with current; or the armature is placed
inside a set of radially supported magnetic poles.
ANSWER: C
39. A dc generator whose excitation is produced by a winding connected to its own positive and negative terminals.
A. series generator
B. separately excited shunt generator
C. self-excited shunt generator
D. compound generator
ANSWER: C
40. What is true about field poles in electric machines?
A. there are always even number of them
(exist by pair)
B. there are always an odd number of
them
C. there are an even or an odd number of
them
D. none of the above
ANSWER: A
41. In a compound generator, which field winding usually, has a lower resistance?
A. series field winding
B. shunt field winding
C. armature winding
D. excitation winding
ANSWER: A
42. Which winding in a dc-compound generator that is relatively made of fine wires?
A. armature winding
B. excitation winding
C. shunt field winding
D. series field winding
ANSWER: C
43. What important characteristic you should consider in choosing a dc-generator?
A. voltage capacity
B. current capacity
C. voltage vs. load
D. power rating
ANSWER: C
44. What is the purpose of laminating the field poles and armature of a dc machine?
A. to reduce eddy current
B. to avoid contaminants
C. to provide isolation
D. to beautify the machine
ANSWER: A
45. An alternator with a lagging power factor of 0.8 will have a ________ voltage regulation at unity power factor.
A. 0%
B. less than
C. greater than
D. 100%
ANSWER: C
46. With alternators connected in parallel, the frequency of the system can be changed by
A. increasing the field excitation
B. decreasing the field excitation
C. changing the rpm of the prime movers
D. synchronizing the prime movers
ANSWER: C
47. With alternators connected in parallel, the voltage of the system can be changed by
A. changing the field excitation
B. increasing the speed of the prime
movers
C. changing the rpm of the prime movers
D. synchronizing the prime movers
ANSWER: A
48. If an ac generator is to be driven from prime mover having variable speed, such as aircraft engine, a ________ must be used.
A. constant speed drive (CSD)
B. regulator
C. conditioner
D. peak limited
ANSWER: A
49. Find the frequency in kilocycles per second in the armature of a 10 pole, 1,200 rpm generator.
A. 100
B. 1000
C. 10
D. 0.1
ANSWER: D
50. What should be the speed of a 6-pole ac generator in order to have a frequency of 50Hz?
A. 100 rpm
B. 500 rpm
C. 1000 rpm
D. 1500 rpm
ANSWER: C
51. What is the voltage regulation when the full load voltage is the same as no-load voltage assuming a perfect voltage source?
A. 100%
B. 1%
C. 10%
D. 0%
ANSWER: D
52. Calculate the voltage regulation of a generator having a no-load voltage of 220 V and a full load voltage of 180 V.
A. 18%
B. 22%
C. 28%
D. 32%
ANSWER: B
53. Usually used to drive low-speed alternators
A. diesel engines
B. jet propulsion engines
C. steam turbines
D. hydraulic turbines
ANSWER: D
54. Is usually used to drive high-speed alternators
A. diesel engines
B. pneumatic engines
C. steam turbines
D. hydraulic turbines
ANSWER: C
55. Which statement is true regarding alternators?
A. high-speed alternators are smaller than
low-speed
B. low-speed alternators are smaller than
high-speed
C. high-power alternators are smaller than
low-power
D. high-voltage alternators are smaller
than low-voltage ANSWER: A
56. For what reason, why carbon brushes are widely used dc machines?
A. it is abundant
B. it is cheap
C. it has a high voltage drop
D. it lubricates and polishes the contacts
ANSWER: D
57. Alternators have less chance to hunt if driven by
A. steam turbines
B. hydroturbines
C. diesel turbines
D. nuclear reactor
ANSWER: A
58. In alternators, what is the purpose of damper windings?
A. it prevents over speeding
B. it maintain constant speed
C. it prevents hunting
D. it protects overloading
ANSWER: C
59. What term applies to the use of two or more generators to supply a common load?
A. on-line operation
B. series operation
C. cascaded operation
D. parallel operation
ANSWER: D
60. In paralleling ac generators, ________ is very important.
A. voltage level
B. current level
C. phase angle
D. internal resistance
ANSWER: C
61. Description used for generators trying to self-adjust its parameters before paralleling with on line generators.
A. synchronizing
B. sequencing
C. jogging
D. alighning
ANSWER: C
62. In changing power from one generator to another, what do you call the operational sequence wherein the incoming generator is connected first before removing the existing generator?
A. No Break Power Transfer (NBPT)
B. UPS
C. LIFO
D. Standby Power transfer
ANSWER: A
63. What do you mean by break power transfer?
A. The incoming generator will be
connected first to the bus bar before disconnecting the existing generator.
B. The present on-line generator will be
disconnected first before connecting the incoming generator.
C. The incoming generator will only be
connected to the bus bar when the bus bar breaks.
D. The present on-line generator will be
disconnected first and then reconnected together with the incoming generator.
ANSWER: B
64. How alternators rated?
A. in Watts
B. in kW
C. in kVar
D. in kVA
ANSWER: C
65. In electrical power distribution, what do you call the first distribution line from the main generating station?
A. main transmission lines
B. primary distribution lines
C. sub transmission lines
D. secondary distribution lines
ANSWER: A
66. The lines which carry the energy from the transformer to a customer’s services are called ________.
A. main transmission lines
B. primary distribution lines
C. sub transmission lines
D. secondary distribution lines
ANSWER: D
67. In electrical power Generating/distribution Company, which do you think is their highest expenses?
A. generation of power
B. distribution of power to the consumers
C. power transmission
D. substations
ANSWER: B
68. In electrical power distributions, what insulator is generally used?
A. rubber
B. wood
C. plastic
D. porcelain
ANSWER: D
69. Electrical machines refer to machines that convert ________
A. mechanical to electrical energy
B. electrical to mechanical energy
C. electrical energy of one form to
electrical energy of another form
D. all of the above
ANSWER: D
70. Electrical machines that convert electrical energy to mechanical energy.
A. generators
B. motors
C. rotary converters
D. frequency converters
ANSWER: B
71. Synchronous type of ac-motor,
A. uses a dc-generator to supply dc-
excitation to the rotating field
B. uses pulsating dc
C. uses alternator
D. has an ac or dc depending on the type
of machine ANSWER: A
72. Generally in dc motors
A. the armature winding is rotated by a
stationary magnetic field produced by electromagnets or permanent magnets.
B. current is sent into the armature
winding; or the armature winding is usually placed in a stationary laminated iron core and the rotating element may or may not be a set of magnet poles, it depends on the type of motor.
C. the electromagnets or permanent
magnets (magnetic fields) are rotated with respect to the stationary armature winding.
D. the armature winding is supplied with
current; or the armature is placed inside a set of radially supported magnetic poles.
ANSWER: D
73. In ac motors, generally
A. current is sent into the armature
winding; or the armature winding is usually placed in a stationary laminated iron core and the rotating element may or may not be a set of magnet poles, it depends on the type of motor.
B. the armature winding is supplied with
current; or the armature is placed inside a set of radially supported magnetic poles.
C. the armature winding is rotated by a stationary magnetic field produced by
electromagnets or permanent magnets.
D. the electromagnets or permanent
magnets (magnetic fields) are rotated with respect to the stationary armature winding.
ANSWER: A
74. Among the dc motors, which produces the highest torque?
A. series
B. shunt
C. compound
D. differentially compounded
ANSWER: A
75. Dc motor that has the most stable speed.
A. differentially compounded
B. compound
C. shunt
D. series
ANSWER: C
76. In dc motors, when does severe arcing happens?
A. during starting
B. during rated speed
C. during speed fluctuation
D. during shutdown
ANSWER: A
77. What is the primary reason why carbon brushes are preferred over copper brushes in dc motors?
A. they have low loss
B. they are more strong
C. they produce less arcing
D. all of the above
ANSWER: C
78. In dc motors, the emf developed which opposes to the supplied voltage.
A. residual emf
B. induced emf
C. coercive emf
D. counter emf or back emf
ANSWER: D
79. To minimize arcing during starting of dc motors, a resistance should be added to limit the current in the ________
A. series field winding
B. shunt field winding
C. armature winding
D. all of these
ANSWER: C
80. Which dc motors whose speed is greatly affected by a change in load? It will even run-away if the load is removed.
A. series
B. shunt
C. cumulatively compounded
D. differentially compounded
ANSWER: A
81. Motors whose speed can be easily controlled.
A. dc motors
B. ac motors
C. ac & dc motors
D. ac or dc motors
ANSWER: A
82. When a dc motor has no load, what will happen to the back emf?
A. reduces
B. increases
C. becomes maximum
D. becomes zero
ANSWER: C
83. When can we get a maximum mechanical power from a dc motor?
A. Eb = 0
B. Eb = ½V
C. Eb = 1V
D. Eb = 2V
ANSWER: B
84. The torque of a dc motor is
A. directly proportional to the field
strength
B. inversely proportional to the field
strength
C. directly proportional to the armature
current
D. A and C are correct
ANSWER: D
85. One causes why the shaft torque is less than the developed armature torque of a dc motor.
A. eddy current
B. field loss
C. brushes loss
D. friction loss
ANSWER: D
86. For heavy-duty dc motor, how does the effect of armature reaction be corrected?
A. using interpoles & brush shifting
B. using interpoles
C. using compensatory winding
D. B & C are correct
ANSWER: D
87. Considered as a variable speed motor
A. compounded
B. differentially compounded
C. shunt
D. series
ANSWER: D
88. What is the most common method used in varying the speed of a dc motor?
A. by varying the supply voltage
B. by changing the effective number of
conductors in series
C. by varying the armature resistance
D. by varying the field strength
ANSWER: D
89. The running speed of a dc series motor is greatly affected by what factor?
A. field excitation
B. load
C. armature resistance
D. supply voltage
ANSWER: B
90. In choosing a motor for a particular application, what characteristic you should consider?
A. speed-torque
B. speed-armature current
C. speed efficiency
D. speed power
ANSWER: A
91. What will happen to the dc shunt motor if the load torque greatly increases?
A. the speed will decrease
B. there will be a great increase in current
C. the speed almost remains constant
D. B and C are correct
ANSWER: D
92. What will happen to a dc series motor when its load is removed?
A. the motor will stop
B. the motor speed remains the same
C. the torque remains the same
D. the motor will overspeed
ANSWER: D
93. A motor whose speed increases as the load is increased.
A. series dc
B. dc shunt
C. cumulatively compounded
D. differentially compounded
ANSWER: D
94. Factor(s) that affect iron losses in a dc motor.
A. flux
B. speed
C. armature resistance and flux
D. A and B are correct
ANSWER: D
95. One advantage of a cumulatively compounded motor is that it does not run widely at light loads, this feature is due to
A. shunt winding
B. brake winding
C. series winding
D. clutch winding
ANSWER: A
96. In applications where an almost constant speed is required, a _______ motor is a good choice.
A. dc shunt
B. dc series
C. cumulatively compounded
D. differentially compounded
ANSWER: A
97. In applications where a high torque is needed during starting a _______ motor is preferred.
A. dc shunt
B. dc series
C. differentially compounded
D. cumulatively compounded
ANSWER: B
98. In applications where sudden heavy loads happen for short duration, a _______ motor is the best choice.
A. dc shunt
B. dc series
C. cumulatively compounded
D. differentially compounded
ANSWER: C
99. In motors of the same rating, which has the least starting torque?
A. dc shunt
B. dc series
C. differentially compounded
D. cumulatively compounded
ANSWER: A
100. Factor(s) that affect friction and winding loses in dc motors.
A. speed
B. armature current
C. interpoles
D. armature resistance
ANSWER: A
101. In dc motors, power loss is contributed greatly by
A. flux loss
B. core loss
C. copper loss
D. mechanical friction
ANSWER: C
102. Dirt on the commutator may produce
A. isolation
B. excessive sparking
C. power loss
D. lower torque
ANSWER: B
103. Motor vibrations are usually caused by
A. loose coupling
B. dirt on the commutator
C. much brush tension
D. worn bearings
ANSWER: D
104. When a motor is overloaded, it will usually
A. slow down
B. speed up
C. vibrate
D. overheat
ANSWER: D
105. Which motor that produces the highest increase in torque considering the same increase in current?
A. dc shunt
B. dc series
C. differentially compounded
D. cumulatively compounded
ANSWER: B
106. When an armature opens in dc motor, it may cause
A. intermittent sparking
B. an increase in speed
C. the motor to slow down
D. the motor to stop rotating
ANSWER: A
107. Why do motors take large current during starting?
A. the armature resistance is still low
B. the field produced is still weak
C. it has to break the momentum
D. there’s still a low back emf
ANSWER: D
108. In dc motors, the speed will
A. increase with an increase in field
strength
B. decrease with an increase in field
strength
C. decrease as the supply voltage is
increased
D. B and C are correct
ANSWER: B
109. When armature current is increased in a dc motor, its armature reaction will
A. also increase
B. decrease
C. increase exponentially
D. decrease exponentially
ANSWER: A
110. Why does in dc motor, brushes are positioned such that they will be with the direction of the rotation?
A. to reduce sparking
B. to last long
C. to have less loss
D. all of the above
ANSWER: A
111. Motors are used to convert electrical energy to mechanical energy. What type of motor that is best suited for heavy-load application?
A. dc series motors
B. dc compound motors
C. single phase motors
D. polyphase motors
ANSWER: D
112. DC shunt motor speed can be controlled electronically by using a _______ in series with the armature winding.
A. thyrector
B. potentiometer
C. rheostat
D. thyristor
ANSWER: D
113. Which thyristor is commonly used is motor speed control?
A. triac
B. diac
C. SCR
D. SUS
ANSWER: C
114. In controlling motor speed, the SCRs controls the
A. number of pulses
B. phase angle
C. firing angle
D. any of these
ANSWER: C
115. How do you reverse the rotation of a dc shunt
motor?
A. By reversing the direction of the field
current, leaving the armature current the same.
B. By reversing the direction of the
armature current, leaving the field current the same.
C. By reversing both field and armature
current
D. Either A or B
ANSWER: D
116. In motor speed control, what is responsible for SCR firing?
A. trigger circuit
B. threshold circuit
C. reference circuit
D. holding circuit
ANSWER: A
117. A circuit that converts ac-voltage to dc-voltage
A. rectifier
B. inverter
C. dc-converter
D. ac-converter
ANSWER: A
118. Conversion from dc-voltage to another dc-voltage requires a
A. inverter
B. cycloconverter
C. dc-converter
D. ac-converter
ANSWER: C
119. A converter that changes ac-voltage to another ac-voltage level.
A. inverter
B. cycloconverter
C. dc-converter
D. ac-converter
ANSWER: D
120. What converter must be used if one wished to change dc-voltage into ac-voltage?
A. inverter
B. cycloconverter
C. dc-converter
D. ac-converter
ANSWER: A
121. A converter that changes ac-voltage frequency from one to another.
A. inverter
B. cycloconverter
C. dc-converter
D. ac-converter
ANSWER: B
122. In electronic converters, what signal is mostly used to trigger the active device?
A. sine-wave
B. square-wave
C. triangular-wave
D. sawtooth-wave
ANSWER: B
123. A transformer consist of the following:
A. An inductance and resistance
B. A parallel resonant circuit
C. A capacitor and an inductor
D. Two coils wound on a common core
ANSWER: D
124. Transformer is considered by many as an efficient device due to the fact that
A. it uses an inductive coupling
B. it is magnetically coupled
C. it is a static device
D. it is electrically coupled
ANSWER: C
125. With transformer, what is measured when performing open-circuit test?
A. turns ratio
B. copper loss
C. leakage reactance
D. turns impedance
ANSWER: B
126. Open-circuit test with transformers is always done on what winding?
A. low-voltage
B. high-voltage
C. primary
D. secondary
ANSWER: A
127. Short-circuit test with transformers is always done on what winding?
A. low-voltage
B. high-voltage
C. primary
D. secondary
ANSWER: A
128. When the transformer secondary winding is short-circuited, its primary inductance will
A. become zero
B. decrease
C. increase
D. not be affected
ANSWER: C
129. Cooling system for transformers with ratings less than 5kVA
A. forced-air cooling
B. oil-cooling
C. natural air cooling
D. water cooling
ANSWER: C
130. For transformers, zero efficiency happens when it has
A. no-load
B. 1/2 of full-load
C. 2/3 of full-load
D. full-load
ANSWER: A
131. For transformers, maximum efficiency happens when
A. copper loss is zero
B. copper loss is equal to constant loss
C. the primary and secondary windings are
equal
D. the leakage reactances of both windings
are equal ANSWER: B
132. In constructing transformers, the primary and secondary windings should have
A. good electrical coupling
B. loose magnetic coupling
C. tight magnetic coupling
D. best inductive coupling
ANSWER: C
133. What are the two parameters in transformers that are the same in both primary and secondary?
A. power and voltage
B. power and current
C. power and impedance
D. voltage per turn and ampere-turns
ANSWER: D
134. In transformers, the amount of copper used in the primary is
A. less than that of the secondary
B. greater than that of secondary
C. exactly twice that of secondary
D. almost equal as that of secondary
ANSWER: D
135. At very low frequencies, transformers woks poorly because
A. its magnetizing current will be very high
B. its core permeability will be greatly
increased
C. its core permeability will be greatly
reduced
D. its impedance will increase
ANSWER: A
136. What will happen if a power transformer is to be operated at a very high frequency?
A. it will have a very high core loss
B. its impedance will decrease
C. its core permeability will be greatly
increased
D. its core permeability will be greatly
reduced ANSWER: A
137. How are the primary and secondary coupled in autotransformers?
A. electrically
B. magnetically
C. electrically and magnetically
D. capacitively
ANSWER: C
138. In a single-phase transformer, the core flux is
A. constant
B. pulsating
C. alternating
D. alternating and sometimes stable
ANSWER: C
139. What do you think will happen to a transformer when its primary is connected to a DC supply?
A. It will become more efficient
B. It will become less efficient
C. It will have good regulation
D. It might burn out
ANSWER: D
140. Generally, in what application you consider the use of core-type transformers?
A. low voltage and low current
B. low voltage and high current
C. high voltage and low current
D. high voltage and high current
ANSWER: C
141. In ________ transformers, when its primary is
energized the secondary should never be open-circuited.
A. power
B. voltage
C. current
D. matching
ANSWER: C
142. Considered as an ideal transformer
A. the one with no losses and leakage
reactance
B. the one with 100% regulation
C. the one with zero efficiency
D. the one with equal primary and
secondary ANSWER: A
143. What is the effect of air gaps at the transformer core?
A. Its reluctance is decreased
B. It increases eddy current
C. It decreases hysteresis loss
D. It increases magnetizing current
ANSWER: D
144. ________ currents are wasteful currents which flows in cores of transformers and produces heat.
A. Residual
B. Eddy
C. Sneak
D. Magnetizing
ANSWER: B
145. What will happen to the eddy current loss in transformers when the load is increased?
A. will also increase
B. will decrease
C. will become infinite
D. nothing will happen
ANSWER: D
146. Leakage flux in transformers will cause
A. copper loss to increase
B. copper loss to decrease
C. eddy current to decrease
D. voltage drop in the windings
ANSWER: D
147. The increase in temperature in a transformer is mainly due to
A. true power
B. reactive power
C. apparent power
D. virtual power
ANSWER: C
148. In transformers, the voltage per turn at the primary is ________ the secondary.
A. less than that of
B. greater than that of
C. a factor of
D. the same as
ANSWER: D
149. In transformer windings, the more number of turns
A. the higher is the voltage
B. the lower is the voltage
C. the lower is the impedance
D. the higher is the current
ANSWER: A
150. What is true about core-type transformers?
A. It has a shorter magnetic path
B. It has a longer magnetic path
C. It has a very long magnetic path
D. It has an infinite magnetic path
ANSWER: A
151. Practically how many percent is copper loss to the total loss in transformers?
A. 15%
B. 50%
C. 85%
D. 100%
ANSWER: C
152. What is the purpose of laminating the core of a transformer?
A. to decrease eddy current loss
B. to increase eddy current loss
C. to decrease copper loss
D. to decrease hysteresis loss
ANSWER: A
153. Large transformers have approximately an efficiency of
A. 25%
B. 45%
C. 75%
D. 95%
ANSWER: D
154. The loss in a transformer due to the changing field is called
A. leakage
B. hysteresis loss
C. eddy loss
D. keeper
ANSWER: B
155. The ratio of the amount of magnetic flux linking a secondary coil compared to the flux generated by the primary coil:
A. coupling factor
B. mutual coupling
C. coefficient of coupling
D. hysteresis factor
ANSWER: C
156. Mutual inductance between two coils can be decreased by
A. moving the coils apart
B. inserting an iron core
C. moving the coils close
D. reducing the reluctance
ANSWER: A
157. An advantage of full-wave rectifier over half-wave rectifier.
A. Each diode can cool-off during half of
each input cycle
B. The ripple frequency is lower
C. The tube will conduct during both
halves of the input cycle
D. Output voltage is lower with more ripple
ANSWER: C
158. One of the following items below is not one of the main components of an alternating current power supply.
A. Power transformer
B. Voltage regulator
C. Rectifier
D. Filter
ANSWER: C
159. Most electronic devices/circuits require dc-voltage to operate. A battery is a good power source, however, its operating time is limited. The use of battery also proves to be expensive. A more practical alternative is to use the household main supply, and since this is an ac-voltage, it must be converted to a dc-voltage. The circuit that converts this ac-voltage to a dc-voltage is called
A. rectifier
B. clamper
C. filter
D. regulator
ANSWER: A
160. A rectifier that uses either the positive or negative portion only of the main ac-supply
A. half-wave
B. full-wave
C. full-wave bridge
D. all of the above
ANSWER: A
161. For a half-wave rectifier, the average output voltage is _______ of the maximum ac-voltage.
A. 31.8%
B. 45%
C. 63.6%
D. 90%
ANSWER: A
162. Percent ripple of a half-wave rectifier.
A. 24%
B. 48%
C. 63.6%
D. 121%
ANSWER: D
163. Calculate the dc-voltage at the output of a half-wave rectifier with a 12Vrms input.
A. 2.7 V
B. 3.8 V
C. 4.5 V
D. 5.4 V
ANSWER: D
164. To double the capability of the half-wave rectifier, a _______ must be used.
A. full-wave rectifier
B. full-wave bridge
C. dual-supply
D. A or B is correct
ANSWER: D
165. Fullwave rectifier defers from fullwave bridge in what aspect?
A. fullwave uses two diodes, while four for
fullwave bridge
B. diode’s PIV in fullwave is twice that of
fullwave bridge
C. fullwave generates less heat than
fullwave bridge
D. all of the above
ANSWER: D
166. Common to both full-wave and full-wave bridge rectifiers
A. dc-voltage
B. ripple factor
C. ripple frequency and percent ripple
D. all are correct
ANSWER: D
167. Find direct current voltage from a full-wave rectifier with 120 V peak rectified voltage.
A. 60 V
B. 7.639 V
C. 76.39 V
D. 6.0 V
ANSWER: C
168. The dc-voltage of a full-wave bridge rectifier.
A. 0.318 Vmax
B. 0.45 Vmax
C. 0.636 Vmax
D. 0.90 Vmax
ANSWER: C
169. Relate the magnitude of the dc-output voltage to the ac input rms voltage of a full-wave rectifier.
A. VDC = 0.318 Vrms
B. VDC = 0.45 Vrms
C. VDC = 0.636 Vrms
D. VDC = 0.90 Vrms
ANSWER: D
170. Determine the dc-voltage of a full-wave bridge rectifier when the input ac-voltage is 24 Vrms.
A. 7.63 V
B. 10.8 V
C. 15.3 V
D. 21.6 V
ANSWER: D
171. Ripple factor of a full-wave rectifier.
A. 0.318
B. 0.48
C. 0.9
D. 1.21
ANSWER: B
172. To improve the dc output voltage of a power supply, a _______
A. shunt resistor may be installed
B. limiting resistor may be installed
C. feedback element may be installed
D. filter capacitor may be installed
ANSWER: D
173. Factor(s) that can reduce the ripple voltage of a power supply.
A. filter capacitance
B. reduction of load current
C. increase in input frequency
D. all of the above
ANSWER: D
174. Making the filter capacitor large in a power supply results to
A. an increase of the ripple voltage
B. an increase of the dc-voltage
C. a decrease of the ripple frequency
D. A and B above
ANSWER: B
175. Find the ripple factor (kr) of a sinusoidal signal with peak ripple of 4 volts on an average of 30.
A. 0.094
B. 0.013
C. 0.130
D. 0.94
ANSWER: A
176. Calculate the peak-to-peak ripple voltage of a 20 V full-wave power supply with a filter capacitor C = 220 µF when delivering a load current of 50 mA.
A. 2.0 Vpp
B. 3.79 Vpp
C. 5.67 Vpp
D. 7.9 Vpp
ANSWER: A
177. In capacitor-filtered power supply, what will happen to the ripple voltage if the load is disconnected?
A. increases
B. becomes infinite
C. becomes unpredictable
D. drops to zero
ANSWER: D
178. For a power supply with a peak-to-peak ripple voltage of 5 Vpp, determine its rms ripple.
A. 1.44 Vrms
B. 1.77 Vrms
C. 2.88 Vrms
D. 3.54 Vrms
ANSWER: B
179. A 20-Vdc power supply was found to have a ripple voltage of 2 Vrms when supplying 1.5 amps load. Calculate its percent ripple.
A. 7.5 %
B. 10.0 %
C. 12.5 %
D. 15.0 %
ANSWER: B
180. Which power supply filter gives the smallest ripple voltage?
A. capacitor filter
B. RC-filter
C. LC-filter
D. multi-section LC-filter
ANSWER: D
181. Ripple voltage in power supplies causes unwanted effects on the load it is supplying, i.e. a hum in audio amplifiers. To minimize this effect several filtering techniques are used, however, ripple still exists. What is a better alternative to reduce further the ripples?
A. truncation
B. clipping
C. clamping
D. regulation
ANSWER: D
182. A voltage regulator connected in parallel with the load.
A. series regulator
B. parallel regulator
C. shunt regulator
D. switching regulator
ANSWER: C
183. Which regulator is the most efficient?
A. series
B. shunt
C. switching
D. modulating
ANSWER: B
184. Voltage reference element in most voltage regulators
A. diac
B. thyrector
C. zener diode
D. transistor
ANSWER: C
185. In voltage regulators, what do you call the element/device that controls the amount of current/voltage/power?
A. sampling circuit
B. comparator
C. limiter
D. control element
ANSWER: D
186. The element/device used as a comparator in most voltage regulators.
A. zener diode
B. BJT
C. IGBT
D. op-amp
ANSWER: D
187. Sampling circuit used in most voltage regulators.
A. voltage divider network
B. bleeder network
C. crowbar
D. bootstrap circuit
ANSWER: A
188. Most voltage regulators used _______ as their control element.
A. BJT
B. SBS
C. UJT
D. JFET
ANSWER: A
189. The most efficient voltage regulator and is therefore used in high-current high-voltage applications.
A. series regulators
B. shunt regulators
C. hybrid regulators
D. switching regulators
ANSWER: D
190. A 12 VDC power supply is regulated using 7805 IC and is used in TTL circuits that require a 0.2 amps current. Determine the dropout voltage of the system.
A. 4 V
B. 5 V
C. 6 V
D. 7 V
ANSWER: D
191. A load draws 1 A current from a 10-V regulated power supply. Calculate the power dissipated by the regulator if it has an input voltage of 16 V.
A. 6 Watts
B. 10 Watts
C. 12 Watts
D. 16 Watts
ANSWER: A
192. Three-terminal fixed positive voltage regulators commonly used in industry.
A. 78XX series
B. 79XX series
C. 723 IC regulator
D. 317 regulator
ANSWER: A
193. What is the regulated output voltage of a 7924 regulator?
A. + 4 V
B. - 4 V
C. + 24 V
D. - 24 V
ANSWER: D
194. A three-terminal variable positive voltage regulator
A. 317
B. 337
C. 723
D. 741
ANSWER: A
195. What three-terminal IC regulator that has a variable negative voltage output?
A. 317
B. 337
C. 723
D. 741
ANSWER: B
196. In a three-terminal adjustable positive voltage regulator (317), what is the band-gap voltage between the output terminal and adjustment terminal?
A. 1.25 V
B. 2.5 V
C. 3.25 V
D. 4.125 V
ANSWER: A
197. Typical ripple rejection of most three-terminal voltage regulators
A. 0.1 %
B. 0.8 %
C. 1.2 %
D. 2.0 %
ANSWER: A
198. The three-terminal voltage regulators, such as the 78XX series has a typical current rating of 1.5 amperes. If a high current is required, say 30 amperes, how will you make modifications from this regulator in order to provide the required current?
A. by cascading them
B. by the use of a crowbar circuit
C. by connecting them in parallel
D. by the use of external pass transistor
ANSWER: D
199. What is the simplest way of protecting power supplies from reverse-polarity/reverse-current flow?
A. by a forward-biased diode
B. by a reverse-biased diode
C. by a crowbar circuit
D. by a snubber circuit
ANSWER: B
200. A crowbar circuit is used
A. to monitor the output current of a
power supply and automatically shuts down the system when an overload occur.
B. to monitor the temperature of a power
supply and switches the cooling fan when a threshold temperature is reached.
C. as voltage reference in regulated power
supplies.
D. as an over-voltage protection in power
supplies. ANSWER: D
201. Technique(s) in using low-power, low-voltage transistors in high voltage regulators.
A. ground return regulation
B. by lifting the regulator above ground
C. connecting them in series
D. all of the above
ANSWER: D
202. Which of the regulators dissipates less power and therefore generates less heat?
A. series
B. shunt
C. switching
D. UPS
ANSWER: C
203. In switching regulators, what are the semiconductor devices that can be used as controllable power switches?
A. BJTs and MDs
B. MOSFETs and IGBT
C. GTOs and thyristors
D. all of the above
ANSWER: D
204. In voltage regulators, the control element plays a major part in providing proper and
efficient regulation. What are the desirable characteristics of the control element to be used if excellent regulator is desired?
A. very small off-state leakage current and
high on-state current ratings
B. large forward and reverse blocking
voltage and very small on-sate voltage
C. short turn-on and turn-off times so that
it can be used in high-speed switching regulators
D. all of the above
ANSWER: D
205. Active devices used in switching regulators may experience large over-currents during conduction (turn-on-state) and large over-voltages during turn-off. These excessive currents and voltages may cause distraction or damage of the active devices. How do we protect them?
A. by the use of a crowbar circuit
B. by providing a buck-boost circuit
C. by shunting a thyrector
D. by installing a snubber circuit
ANSWER: D
206. One of the major concerns in power electronics is to clean-up or shape-up the utility-supply voltage (the wall-outlet 220 V/60 Hz) from disturbances such as, overvolt, undervolt, voltage spikes, and harmonic distortions. What circuit is used for this?
A. power conditioners
B. UPS
C. power inverters
D. line scanning
ANSWER: A
207. A power supply that continuously provides protection against undervoltage, overvoltage and even power outages.
A. standby power supply
B. uninterruptible power supply
C. power conditioners
D. regulated power supply
ANSWER: B
TEST6.
1. What is the degree of exactness of measurement when compared to the expected value of the variable being measured?
A. Accuracy B. Error C. Deviation D. Precision
ANSWER: A
2. The art or process of determining the existence
or knowing the magnitude of something, directly or indirectly in terms of a recognized standard.
A. Measurement B. Testing C. Recording D. Evaluating
ANSWER: A
3. A procedure or sequence of operations for determining whether a component or equipment is functioning or working normally.
A. Measurement B. Test C. Recording D. Evaluating
ANSWER: B
4. In measurement, what do you call the degree of exactness compared to the expected value of the variable being measured?
A. precision
B. accuracy C. sharpness D. correctness
ANSWER: B
5. A measure of consistency or repeatability of measurements is called
A. precision B. accuracy C. sharpness D. correctness
ANSWER: A
6. Precision is also known as A. correctness B. accuracy C. sharpness D. reproducibility
ANSWER: D
7. In measurements, the sum of a set of numbers divided by the total number of pieces of data in the given set is called
A. geometric mean B. algebraic mean C. arithmetic mean D. effective value
ANSWER: C
8. The deviation of a reading from the expected value
A. accuracy B. precision C. error D. difference
ANSWER: C
9. Errors due to frictions of the meter movement, incorrect spring tension, improper calibration or faulty instruments:
A. Observational errors B. Environmental errors C. Instrument errors D. Gross errors
ANSWER: C
10. When an instrument is subjected to harsh environments such as high temperature, strong magnetic, electrostatic or electromagnetic field, it may have detrimental effects and cause errors known as
A. Observational errors B. Environmental errors C. Instrument errors D. Gross errors
ANSWER: B
11. Errors introduced by the observer or user. A. Observational errors B. Environmental errors
C. Instrument errors D. Gross errors
ANSWER: A
12. Errors in analog meter reading due to your physical position with respect to the meter scale.
A. parallax error B. angular error C. linear error D. deviation
ANSWER: A
13. What do you call the difference between any number within the set of numbers and the arithmetic mean of that set of numbers?
A. parallax error B. angular error C. linear error D. deviation
ANSWER: D
14. An instrument or device having recognized permanent or stable value that is used as a reference.
A. standard instrument/device B. reference instrument/device C. fixed instrument/device D. ideal instrument/device
ANSWER: A
15. The smallest change in a measured variable to which an instrument will respond.
A. quantize value B. resolution C. minimum D. step size
ANSWER: B
16. A device or mechanism used to determine the value of a quantity under observation.
A. measuring kit B. evaluator C. instrument D. sensor
ANSWER: C
17. What is the basic unit for measuring current flow?
A. coulomb B. ampere C. atomic weight D. volt
ANSWER: B
18. An instrument used to detect and measure the presence of electrical current is generally called
A. D’Arsonval meter B. electrodynamometer C. galvanometer D. potentiometer
ANSWER: C
19. What is the common type of meter movement?
A. Fixed coil B. Farad C. D’Arsonval D. Digital
ANSWER: C
20. A permanent-magnet moving-coil instrument. A. induction instrument B. D’Arsonval meter movement C. moving-iron instrument D. moving-magnet instrument
ANSWER: B
21. An instrument which depends on current in one or more foxed-coils acting on one or more pieces of soft iron, at least one of which is movable.
A. moving-magnet instrument B. moving-iron instrument C. D’Arsonval meter movement D. induction instrument
ANSWER: B
22. What is that device, which depends on the action of a movable permanent magnet, in aligning itself in the resultant field, produced either by a fixed permanent magnet and adjacent coil or coils carrying current, or by two or more current-carrying coils whose axes are displaced by a fixed angle?
A. D’Arsonval meter movement B. induction instrument C. moving-magnet instrument D. moving-iron instrument
ANSWER: C
23. What ammeter is mostly used in measuring high-frequency currents?
A. electrostatic B. moving-coil C. dynamometer D. thermocouple
ANSWER: D
24. Measurement of high dc-voltages is usually done by using
A. Electrostatic B. moving-coil C. dynamometer D. thermocouple
ANSWER: A
25. Measuring instrument that can be used only to measure voltages.
A. electrostatic B. thermocouple C. dynamometer D. permanent-magnet moving-coil
ANSWER: A
26. This instrument measures temperatures by
electric means, especially temperatures beyond the range of mercury thermometers.
A. pyrometer B. electrostatic instrument C. moving-magnet instrument D. permanent-magnet moving-coil
instrument ANSWER: A
27. This instrument refers to that one, which
measures the intensity of the radiation, received from any portion of the sky.
A. megaohmmeter B. pyranometer C. Megger D. galvanometer
ANSWER: B
28. What is the normal indication on a megger (megohmmeter) when checking insulation?
A. one B. infinity C. middle of scale D. zero
ANSWER: B
29. Resistance measuring instrument particularly used in determining the insulation resistance.
A. megaohmmeter B. Megger C. galvanometer D. A or B are correct
ANSWER: D
30. An electrodynamic meter used to measure power A. hook-on type voltmeter
B. wattmeter C. watt-hour meter D. multi-meter
ANSWER: B
31. A device used to mechanically measure the output power of a motor.
A. dynamometer B. Megger C. concentric-vane instrument D. radial-vane instrument
ANSWER: A
32. An indicating instrument whose movable coils rotate between two stationary coils, usually used as wattmeter.
A. induction-type meter B. radial-vane instrument C. electrodynamometer D. concentric-vane instrument
ANSWER: C
33. Dynamometers are mostly used as
A. voltmeter B. ammeter C. ohmmeter D. wattmeter
ANSWER: D
34. What damping method is generally used in dynamometers?
A. spring B. fluid friction C. eddy-current damping D. air friction
ANSWER: D
35. Which dynamometer instrument has a uniform scale?
A. voltmeter B. ammeter C. ohmmeter D. wattmeter
ANSWER: D
36. For a dynamometer to be able to measure high current, a ________ should be used.
A. shunt resistor B. multiplier C. CVDT D. current transformer
ANSWER: D
37. Error in voltmeter reading is due to A. insertion B. loading C. battery aging D. conversion
ANSWER: B
38. Error in ammeter reading id due to
A. insertion B. loading C. battery aging D. conversion
ANSWER: A
39. Which type of meter requires its own power source?
A. A voltmeter B. An ammeter C. An ohmmeter D. A wattmeter
ANSWER: C
40. Error in ohmmeter reading is due to A. insertion B. loading C. battery aging D. meter friction
ANSWER: C
41. Decreasing the value of the shunt resistor of an ammeter, its current measuring capability
A. increases B. decreases C. remains constant D. none of the above
ANSWER: A
42. Increasing the value of the series resistor of a voltmeter, its voltage measuring capability
A. increases B. decreases C. remains constant D. none of the above
ANSWER: A
43. A device that is used to measure current without opening the circuit
A. megger test B. clamp probe C. ammeter D. multi-meter
ANSWER: B
44. Which of the ammeter below that has no insertion error?
A. D’Arsonval meter B. clamp-meter C. micrometer D. meter with current transformer
ANSWER: B
45. To prevent damage of the multirange ammeter during selection, a/an _______ should be used.
A. direct shunt B. selected shunt C. Ayrton shunt D. shunt fuse
ANSWER: C
46. For the greatest accuracy, what should be the input impedance of a VOM be?
A. 1,000 ohms/V B. 50,000 ohms/V C. as large as possible D. as small as possible
ANSWER: C
47. Voltage measurement in a high impedance circuit requires a voltmeter with
A. low input impedance B. high input impedance C. high voltage probe D. low voltage probe
ANSWER: B
48. A meter has a full-scale current of 50μA, what is its sensitivity?
A. 20kΩ/V B. 20V/Ω C. 50kΩ/V D. 50μA/V
ANSWER: A
49. If a meter with a full-scale current of 100μA is
used as an ac voltmeter with half-wave rectification, its ac sensitivity is
A. 10,000 Ω/V B. 4,500 Ω/V C. 9,000 Ω/V D. 100 Ω/V
ANSWER: B
50. In order to make an accurate measurement as possible, the internal resistance of a voltmeter must be
A. as high as possible B. as low as possible C. proportional to the voltage range D. proportional to the current range
ANSWER: A
51. An ammeter has a full-scale deflection current of 100mA. If the same ammeter is used to measure a full-scale current of 1.0 ampere, what is the value of the shunt resistor in ohms if the voltage across the meter is 9.0 volts?
A. 9.0 B. 10 C. 900 D. 100
ANSWER: B
52. What is the purpose of the rheostat in ohmmeter?
A. balancing resistance B. counter resistance of measured circuit C. coil resistance D. compensate aging battery of the meter
ANSWER: D
53. The zero-adjust control in an analog type ohmmeter is used to
A. compensate for the differing internal battery voltage
B. make sure the pointer is moving correctly
C. align the infinity resistance position D. align the zero-voltage position
ANSWER: A
54. The scale of a hot wire instrument is a/an __________ function.
A. linear B. squared C. log D. exponential
ANSWER: B
55. Moving iron instrument have a scale function that is
A. log B. exponential C. linear
D. squared ANSWER: D
56. To increase the measuring capability of a
moving-iron ac ammeter, a _______ should be used.
A. shunt B. multiplier C. swamping resistors D. different number of turns of operating
coil ANSWER: D
57. Which electrical instruments below is the most
sensitive? A. moving-iron B. dynamometer C. thermocouple D. PMMC
ANSWER: D
58. Basically, a PMMC instrument can be used only in
A. ac measurements B. dc measurements C. rms measurements D. all of the above
ANSWER: B
59. Controlling torque in PMMC. A. spring action B. magnetic action C. electromagnetic action D. tension cable
ANSWER: A
60. What damping method is used in induction type ammeters?
A. air friction B. electrostatic damping C. fluid friction D. eddy current damping
ANSWER: D
61. Induction type instruments are mostly used as A. voltmeter B. ammeter C. wattmeter D. watt-hour meter
ANSWER: D
62. In indicating instruments, what will happen to the controlling torque if the deflection becomes greater?
A. increases B. decreases C. remains unchanged D. drops to zero
ANSWER: A
63. The force(s) that is(are) acting on the pointer of
an indicating instrument as it rest on its final deflected position. (Note: damping torque is 0).
A. controlling torque B. deflecting torque C. damping torque D. A & B above
ANSWER: D
64. What is(are) the force(s) acting on the pointer of an indicating instrument when it is in motion?
A. controlling and deflecting torques B. damping and deflecting torques C. controlling and damping torques D. controlling, damping, deflecting torques
ASNWER: D
65. Material that is mostly used as a pointer in indicating instruments.
A. soft iron B. aluminum C. silver D. stainless
ANSWER: B
66. A Kelvin electrostatic voltmeter uses what method of damping?
A. fluid friction B. spring action C. mechanical friction D. eddy-current damping
ANSWER: A
67. Shunts in meters should have a _________ temperature coefficient of resistance.
A. positive B. negative C. very small D. very large
ANSWER: C
68. In a moving coil ammeter, a _________ is connected in series with the soil to compensate for temperature variations.
A. limiting resistor B. shunt resistor C. multiplier D. swamping resistor
ANSWER: D
69. Where can we use the dynamometer? A. dc only B. ac only C. dc and ac D. peak measurement
ANSWER: C
70. What is the meter that depends for its operation on the forces of attraction and repulsion between electrically charged bodies?
A. induction instrument B. electrostatic instrument
C. moving-magnet instrument D. D’Arsonval meter movement
ANSWER: B
71. What do you call of an instrument that depends for its operation on the reaction between magnetic flux set up by currents in fixed windings and other currents set up by electromagnetic induction in movable conducting parts?
A. induction instrument B. electrostatic instrument C. moving-magnet instrument D. D’Arsonval meter movement
ANSWER: A
72. A meter for its operation, it depends on a movable iron vane which aligns itself in the resultant field of a permanent magnet and an adjacent current carrying coil.
A. induction instrument B. electrostatic instrument C. moving-magnet instrument D. permanent-magnet moving coil-
instrument ANSWER: D
73. What is the measuring instrument that uses the force of repulsion between fixed and movable magnetized iron vanes, or the force between a coil and a pivoted vane-shaped piece of soft iron to move the indicating pointer?
A. pyrometer B. vane-type instrument C. electrostatic instrument D. moving-magnet instrument
ANSWER: B
74. It’s an electrostatic voltmeter in which an assembly of figure – 8 – shaped metal plates rotates between the plates of a stationary assembly when a voltage is applied between the assemblies. The length of the arc of rotation is proportional to the electrostatic attraction and thus, to the applied voltage.
A. varmeter B. variometer C. potentiometer D. Kelvin voltmeter
ANSWER: D
75. What is that instrument used for measuring the strength and direction of magnetic fields?
A. varmeter B. potentiometer C. magnetometer D. Kelvin voltmeter
ANSWER: C
76. What do you call of that instrument used for measuring reactive power in vars?
A. varmeter B. pyrometer C. reactive volt-ampere meter D. A or C is correct
ANSWER: D
77. What is this instrument or circuit that has four or more arms, by means of which one or more of the electrical constants of an unknown component may be measured?
A. bridge B. Hazeltine circuit C. Loftin – White circuit D. D’Arsonval meter movement
ANSWER: A
78. A four-arm bridge. Al arms of which are predominantly resistive; used for measuring resistance.
A. bridge B. resistance bridge C. Wheatstone bridge D. B or C is correct
ANSWER: D
79. This is the method of using a Wheatstone bridge to determine the distance from the test point to a fault in a telephone or telegraph line or cable.
A. Mesh B. Varley loop C. Batten system D. Cordonnier system
ANSWER: B
80. This refers to a four-arm ac bridge used for measuring inductance against a standard capacitance.
A. Maxwell bridge
B. slide-wire bridge C. resistance bridge D. Wheatstone bridge
ANSWER: A
81. Refers to an ac bridge for measuring the inductance and Q of an inductor in terms of resistance, frequency and a standard capacitance.
A. Hay bridge B. Maxwell bridge C. slide-wire bridge D. Wheatstone bridge
ANSWER: A 82. This is a special bridge for measuring very low
resistance (0.1Ω or less). The arrangement of the bridge reduces the effects of contact resistance, which causes significant error when such low resistances are connected to conventional resistances bridges.
A. Hay bridge B. Maxwell bridge C. Wheatstone bridge
D. Kelvin double bridge ANSWER: D
83. A type of four-arm capacitance bridge in which
the unknown capacitance is compared with a standard capacitance. This bridge is frequently employed in testing electrolytic capacitors, to which a dc polarizing voltage is applied during the measurement. What is this bridge?
A. Hay bridge B. Maxwell bridge C. Schering bridge D. Wheatstone bridge
ANSWER: C
84. What do you call of that frequency-sensitive bridge in which two adjacent arms are resistances and the other two arms are RC combinations?
A. Hay bridge B. Wein bridge C. Maxwell bridge D. Schering bridge
ANSWER: B
85. When the capacitors of a Wein bridge are replaced by inductors, the bridge becomes
A. Wein-bridge filter B. variometer C. Schering bridge D. Wein inductance bridge
ANSWER: D
86. A simplified version of the Wheatstone bridge wherein, two of the ratio arms are replaced by a 100 cm long Manganin of uniform cross-sections and provided with a slider.
A. Hay bridge
B. Schering bridge C. slide-wire bridge D. Wein inductance bridge
ANSWER: C
87. Bridge used to measure both inductive and capacitive impedances at higher frequencies.
A. Hay bridge B. Schering bridge C. Wein bridge D. radio-frequency bridge
ANSWER: D 88. A bridge wherein all legs are electrically identical
A. balance bridge B. balance circuit C. balance line D. all of the above
ANSWER: A
89. Comparison between dc and ac measuring instruments
A. generally, ac instruments are less sensitive than dc instruments
B. errors such as induced emfs, frequency variations, and harmonic-current components are only present in ac instruments
C. in ac instruments, higher value of current is needed than in dc instruments to produce the same deflection
D. all of these are correct ANSWER: D
90. What is an electronic instrument capable of
showing on screen and maybe on print, relative spacing of transmitter carriers, their sidebands and harmonics?
A. Counters B. Spectrum analyzer C. Triggered oscilloscope D. Multimeter
ANSWER: B
91. An instrument capable of displaying simultaneously the amplitude of signals having different frequencies.
A. oscilloscope B. spectrum analyzer C. VTVM D. Logic analyzer
ANSWER: B
92. Spectrum analyzer is A. a real-time analyzer B. a non-real time analyzer C. the same as a wave analyzer in all
aspects D. an instrument not dependent on
frequency ANSWER: A
93. Indications of spectrum analyzer is presented by
means of A. a moving meter B. an iron vane C. a CRT D. a LED
ANSWER: C
94. An electronic measuring device that provide instantaneous visual indication of voltage excursions.
A. voltmeter B. power meter C. oscilloscope D. power line meter
ANSWER: C
95. An instrument that is capable of displaying waveforms by means of fluorescence in a CRT.
A. oscilloscope B. wave analyzer C. spectrum analyzer
D. distortion analyzer ANSWER: A
96. Types of oscilloscopes that are able retain the
display for a longer period for analysis. The display is retained by the use of flood gun.
A. sampling oscilloscope B. digital storage oscilloscope C. storage oscilloscope D. delayed sweep oscilloscope
ANSWER: C
97. What do call an oscilloscope that uses sampling technique in processing signals having frequencies beyond its normal capabilities?
A. sampling oscilloscope B. digital storage oscilloscope C. storage oscilloscope D. delayed sweep oscilloscope
ANSWER: A
98. Generally, oscilloscope uses what type of deflection?
A. magnetic deflection B. electromagnetic deflection C. static deflection D. electrostatic deflection
ANSWER: D
99. A device or instrument, which delivers signals of pre3cise frequency and amplitude, usually over a wide range.
A. synthesizer B. frequency generators C. signal generators D. modulators
ANSWER: C
100. The two most common audio oscillators are A. Wein bridge and Colpitts B. Wein bridge and phase-shift C. Colpitts and Hartley D. Hartley and phase-shift
ANSWER: B
101. What are the two most popular RF oscillators A. Wein bridge and Colpitts B. Wein bridge and phase-shift C. Colpitts and Hartley D. Hartley and phase-shift
ANSWER: C
102. A device or instrument able to generate noise with accurate voltage for test purposes.
A. signal generator B. synthesizer C. frequency generator D. noise generator
ANSWER: D
103. When do you need a noise generator?
A. When starting an oscillators B. When evaluating noise performance of
an oscillator C. When evaluating noise characteristics of
an amplifier D. When performing modulation analysis
ANSWER: C
104. In RF or microwave system, what instrument is used to measure the incidental and reflected signals.
A. oscilloscope B. reflectometer C. incident-wave meter D. spectrum analyzer
ANSWER: B
105. A type of photometer used to measure reflection.
A. photodiode B. reflectometer C. incident-wave meter D. LED
ANSWER: B
106. A tunable RF instrument, which, by means of a sharp dip of an indicating meter, indicates resonance with an external circuit under test.
A. reflectometer B. inclinometer C. dip meter D. Grid-dip meter
ANSWER: C
107. A type of dip meter employing a vacuum tube oscillator, whose indicating dc microammeter is in the grid circuit.
A. reflectometer
B. inclinometer C. dip meter D. Grid-dip meter
ANSWER: D
108. In meter movement, how do you prevent the meter from oscillation and overswing?
A. by shorting B. by coupling C. by swamping D. by damping
ANSWER: D
109. When the meter is insufficiently damped, it is considered as
A. underdamped B. overdamped C. critically damped D. negatively damped
ANSWER: A
110. A meter when _______ damped will become insensitive to small signals.
A. underdamped B. overdamped C. critically damped D. negatively damped
ANSWER: B
TEST7.
1. One type of circuit control device which may be manual, automatic or multi-contact
A. fuse B. breaker C. switch D. relay
ANSWER: B
2. What are the primary methods of controlling electrical power?
A. by using manual switches and rheostats B. by using variable reactance and
transformers C. by using electronic switches, such as
diodes, transistors thyratrons, and thyristors
D. all of the above ANSWER: D
3. Common method(s) of controlling electrical
power with reactance A. switching a tapped inductor B. using a saturable reactor C. by a matching transformer D. A and B above
ANSWER: D
4. A reactive device used in controlling electrical power by using two windings on a common iron core. The control winding is supplied with small
dc-current which causes the reactance of large ac-winding to change accordingly.
A. tapped inductor B. saturable reactor C. auto transformer D. LVDT
ANSWER: B
5. A saturable reactor with regenerative feedback. A. tapped inductor B. auto transformer C. LVDT D. magnetic amplifier
ANSWER: D
6. Thyratrons in industrial electronics refers to ____________.
A. a gas-filled diode B. a vacuum tube C. gas-filled triode D. an electron triode
ANSWER: C
7. An electronic switch that has the highest single-device current capacity and can withstand overloads better.
A. Thyristors B. ignitrons C. SCR D. triac
ANSWER: B
8. A semiconductor, electronic switch that has the highest single-device current rating
A. thyristor B. triac C. SCR D. Quadric
ANSWER: C
9. The purpose of installing thyrectors across the incoming power lines to the speed control system is to ___________
A. cause the motor to caution B. protect drive circuits from high voltage
transient surges C. increase the counter emf D. allow the field winding current to
continue flowing ANSWER: B
10. Semiconductor devices equivalent to thyratrons
are generally called A. thyrector B. thyristor C. diac D. ignitron
ANSWER: B
11. Using electronic devices as switches, what is(are) the general methods of controlling electrical power?
A. phase control B. zero-voltage switching C. static switching D. all of the above
ANSWER: D
12. Which power control switching method that greatly generates RFI or EMI and is therefore limited to low-frequency applications?
A. phase control B. zero-voltage switching C. inverter control D. static switching
ANSWER: A
13. One of the electronic semiconductor devices known as diac, function as
A. four terminal multi-directional switch B. two terminal bi-directional switch C. two terminal unidirectional switch
D. three terminal bi-directional switch ANSWER: B
14. Which of the trigger diodes has the highest
holding voltage? A. bidirectional-trigger diac B. bidirectional-diode-thyristor diac C. Shockley diode D. thyrector
ANSWER: A
15. General term of electronic devices used to control or trigger large-power switching devices.
A. thyristor B. thyrector C. break-over devices D. triggering devices
ANSWER: C
16. A break-over device that is basically a diode. A. thyristor B. thyrector C. thyratron D. triggering diode
ANSWER: D
17. A four-element solid state device that combi9nes the characteristics of both diodes and transistors
A. varactor B. zener diode C. tunnel diode D. SCR
ANSWER: D
18. The most popular thyristor used in electrical power controllers
A. SCR
B. triac C. SCS D. PUT
ANSWER: A
19. Find the two stable operating conditions of an SCR.
A. Conducting and non-conducting B. Oscillating and quiescent C. NPN conduction and PNP conduction D. Forward conducting and reverse
conducting ANSWER: A
20. How do you stop conduction during which SCR is
also conducting? A. remove voltage gate B. increase cathode voltage C. interrupt anode current D. reduce gate current
ANSWER: C
21. How do we turn “ON” or trigger an SCR?
A. by making the gate (G) positive with respect to its cathode (K)
B. by making the gate (G) positive with respect to its anode (A)
C. by making the cathode more positive with respect to the anode
D. A and C above ANSWER: A
22. What is true about SCRs after they are being
switched “ON”? A. The anode (A) to cathode (K) continues
to conduct even if the gate triggering voltage is removed.
B. The gate (G) must be provided with the required holding current to continue its conduction.
C. A small holding voltage at the gate is required for a continuous conduction.
D. B and C above ANSWER: A
23. The voltage across the anode (A) and cathode
(K) terminals of an SCR when conducting. A. holding voltage B. breakdown voltage C. breakback voltage D. trigger voltage
ANSWER: A
24. The minimum amount of current needed for an SCR to conduct continuously.
A. holding current B. triggering current C. threshold current D. average sustaining current
ANSWER: A
25. What is(are) the condition(s) in triggering SCR? A. The gate voltage must be equal to or
greater than the triggering voltage. B. The gate current must be equal to or
greater than the triggering current. C. The anode (A) must be positive with
respect to the cathode. D. all of the above
ANSWER: D
26. The voltage decreased across the anode (A) and cathode (K) of an SCR from non-conducting state to conducting state.
A. holding voltage B. forward breakdown voltage C. triggering voltage D. breakback voltage
ANSWER: D
27. An SCR rated 10 A is used as the controlling switch in a circuit powered by 50Vdc. When the SCR fires ON, its anode (A) to cathode (K) voltage was observed to be 2 V. Calculate the
breakback voltage of the SCR. A. 25 Vdc B. 32 Vdc C. 41 Vdc D. 48 Vdc
ANSWER: D
28. The needed voltage at the gate of an SCR before it conducts.
A. minimum-gate trigger voltage B. maximum-gate trigger voltage C. minimum-gate peak-inverse voltage D. maximum-gate peak-inverse voltage
ANSWER: A
29. What is(are) the gate limitation(s) of SCRs and triacs?
A. maximum-gate power dissipation B. maximum-gate peak-inverse voltage C. maximum-gate trigger current and
voltage D. all of the above
ANSWER: D
30. How can we extend the rating of SCRs? A. by external cooling B. by external circuitry C. by connecting them in series/parallel D. all of the above
ANSWER: D
31. Use of heat sinks, forced air, and water cooling are examples of external cooling in SCRs and other devices. Which of these is the only recommended to be used for the largest power dissipating device?
A. metal heat sinks B. forced air
C. water cooling D. A and B above
ANSWER: C
32. How can we increase the forward-voltage blocking capability of SCRs?
A. by connecting them in series B. by connecting them in parallel C. by cascading them D. by connecting back to back in parallel
ANSWER: A
33. In connecting two SCRs in series, during “OFF” state, the voltage source must be properly shared between them, but due to devices’ differences, there might be unequal voltages across each SCR. How do we equalize these voltages?
A. by installing a snubber circuit B. by adding a gate-to-cathode resistor C. by shunting a capacitor across the
anode (A) and cathode (K) of each SCR D. by using a blocking-equalizing resistor
ANSWER: D
34. What is true regarding blocking-equalizing resistors in SCRs connected in series?
A. Blocking-equalizing resistors are shunted across each SCR.
B. The value of these resistors is about 10% of the value of the blocking resistance of the SCR it is shunted with.
C. These resistors increases the leakage current towards the load.
D. All of the above ANSWER: D
35. A circuit used for voltage equalization during ON-
OFF switching action of SCRs in series. A. snubber circuit B. crow-bar C. clipper D. clamper
ANSWER: A
36. When a high current is needed, SCRs are connected in parallel. The problem with paralleled SCRs is, when they are not perfectly matched, one will conduct first before the other and carries the full-load current that is for sure greater than its maximum rating. To avoid this situation, both SCRs should be turned ON at the same time. How can we do this?
A. by using high triggering gate voltage B. by using a gate-triggering transformer C. by using reactors D. all of the above are possible
ANSWER: D
37. In controlling electrical power using phase control method with SCR/triac being the active
device, what do we call the period of the cycle before the device switches to conduction?
A. trigger time B. trigger delay time C. firing frequency D. firing delay angle
ANSWER: D
38. How many times per second does an SCR is turned ON and OFF when it is operated in a full-wave phase control at a line frequency of 60 Hz?
A. 30 times B. 60 times (HV) C. 90 times D. 120 times (FW)
ANSWER: D
39. A three terminal device that behaves roughly like SCR, except that it can conduct current in either direction when at ON.
A. thyristor B. SUS C. SBS
D. GTO ANSWER: C
40. What is the difference between a triac and a
silicon bilateral switch (SBS)? A. An SBS is usually used as breakover
device, while a triac is a load controlling device.
B. An SBS is for low voltage applications, while a triac is generally for high voltage applications.
C. An SBS has better and stable symmetrical-firing voltage than a triac.
D. all of the above ANSWER: D
41. A triac can be triggered ON by the application of
a A. positive voltage at the gate with respect
to MT1 B. negative voltage at the gate with
respect to MT1 C. positive or negative gate voltage with
respect to MT2 D. all of the above are correct
ANSWER: D
42. Which are the three terminals of a TRIAC? A. Gate, anode 1 and anode 2 B. Gate, source and sink C. Base, emitter and collector D. Emitter, base 1 and base 2
ANSWER: A
43. What are the three terminals of a triac? A. anode 1 (A1), anode 2 (A2) and gate
(G)
B. mainterminal 1 (MT1), mainterminal 2 (MT2), and gate (G)
C. anode (A), cathode (K) and gate (G) D. both A and B are acceptable
ANSWER: D
44. A silicon bilateral switch may be considered as s small power triac, and has three terminals namely,
A. anode 1 (A1), anode 2 (A2) and gate (G)
B. mainterminal 1 (MT1), mainterminal 2 (MT2), and gate (G)
C. anode (A), cathode (K) and gate (G) D. both A and B are acceptable
ANSWER: D
45. A thyristor that is very similar to an SCR except that it has low voltage and current ratings. It is very temperature stable, and is therefore suitable to be used as triggering device.
A. UJT B. GTO
C. SBS D. SUS
ANSWER: D
46. Silicon unilateral switches (SUSs) generally have a breakover voltage of 8 V, however, this value can be altered by normally connecting a zener diode. How is the diode installed?
A. across the gate (G) and cathode (K) terminals, with the diode’s anode at the gate
B. anode to anode, cathode to cathode C. diode’s cathode to SUS’s anode and
diode’s anode to SUS’s cathode D. diode’s cathode to SUS’s gate and
diode’s anode to SUS’s cathode ANSWER: D
47. A silicon unilateral switch (SUS) has a forward breakover voltage of 8 V. a zener diode is connected between its gate and cathode terminals with the diode’s cathode at SUS’s gate. If the zener voltage is 3.9 V, what is the new forward breakover voltage of the device?
A. 0.49 V B. 2.05 V C. 4.50 V D. 11.9 V
ANSWER: C
48. Thyristor whose characteristic curve closely resembles that of SCR’s and SUS’s, except that its forward breakover voltage (+VBO) is not alterable, for the device has no gate terminal.
A. diac B. thyrector C. UJT D. Shockley diode
ANSWER: D
49. What will happen to the forward breakdown or breakover voltage of SCRs and triacs if the gate current is increased?
A. will decrease B. will also increase C. will not change D. will either increase or decrease, it
depends on their current coefficient ANSWER: A
50. A UJT or unijunction transistor is a three
terminal breakover-type switching device. Its three terminals are called base 1, base 2, and emitter. Though this is a transistor and has base and emitter terminals, this operates very different from a BJT and is not used as a linear amplifier. Its applications are for
A. timers and oscillators B. signal generators C. triggering control for SCRs and triacs D. all of the above
ANSWER: D
51. A UJT has an internal resistances of RB1 = 6 KΩ and RB2 = 3 KΩ, what is its interbase resistance?
A. 2 KΩ B. 3 KΩ C. 6 KΩ D. 9 KΩ
ANSWER: D
52. For a unijunction transistor (UJT) to witch ON A. the base 1 voltage should be greater
than the peak voltage B. the base 2 voltage should be greater
than the peak voltage C. the emitter voltage should be greater
than the peak voltage D. the voltage between the emitter and
base 1 should be greater than the peak voltage when emitter being more positive
ANSWER: D
53. Semiconductor devices with inherent ON-OFF behavior and has no linear operating regions are called thryistors. Examples are SCRs, triacs, SUSs, SBSs, Shockley diodes, diacs, PUTs, and SCSs. In selecting thyristors for a particular application, which of the statement below is generally desirable?
A. thyristors with high current and voltage ratings
B. thyristors with high holding current/voltage
C. faster thyristors D. thyristors with high breakback-voltage
ANSWER: D
54. Why does thyristors with high breakback voltage desirable?
A. it dissipates less power B. it generates less heat C. it is more efficient D. all of the above
ANSWER: D
55. Portion in the welding process interval during which the welding current is flowing is called ____________.
A. cool sub-interval B. released interval C. squeeze interval D. heat sub-interval
ANSWER: D
56. In automatic welding system, basically there are how many intervals?
A. 2 B. 5 C. 10 D. 15
ANSWER: B
57. In automatic welding what do you call the first interval wherein the material to be welded are held together?
A. squeeze interval B. weld interval C. hold interval D. standby interval
ANSWER: A
58. After the squeeze interval, what comes next in an automatic welding system?
A. squeeze interval B. weld interval C. hold interval D. standby interval
ANSWER: B
59. During the welding or weld interval, when a welding current is flowing the system is said to be at
A. weld interval B. cool subinterval C. heat subinterval D. hold interval
ANSWER: C
60. The portion of the weld interval during which the current is absent
A. cool subinterval B. heat subinterval C. hold interval D. standby interval
ANSWER: A
61. After the welding interval, it goes to _________ interval wherein the electrode pressure is maintained on the metal surfaces.
A. cool subinterval B. heat subinterval C. hold interval D. standby interval
ANSWER: C
62. Next to hold interval is __________ interval in automatic welding system.
A. squeeze B. cool C. standby D. release
ANSWER: D
63. After the release interval in automatic welding, the system will go to
A. cool interval B. squeeze interval C. standby interval D. hold interval
ANSWER: C
64. Refers to the system that has no feedback and is not self correcting
A. Close-loop system B. Coal slurry system C. Feed forward control system D. Open-loop system
ANSWER: D
65. The system is ____________ if a position servo system does not respond to small changes in the input.
A. under stabilized B. underdamped C. stabilized D. overdamped
ANSWER: D
66. What is the purpose of using a differential synchro instead of a regular synchro?
A. Handles more signals only B. Performs addition and subtraction
function only C. Differential synchros can handle more
signals and also performs addition and subtraction function
D. Handles two signals only ANSWER: C
67. Industrial circuit or system that is not self-
correcting A. open-loop B. closed-loop C. system with feed back D. non-servo
ANSWER: A
68. What do you call a circuit or system that is self-correcting?
A. open-loop B. closed-loop C. system without feed back D. servo
ANSWER: B
69. Open-loop in control system means: A. it has no feedback B. it is not self-correcting C. it is not self-regulating D. all are correct
ANSWER: D
70. In control system, closed-loop means: A. it has feedback B. it is self-correcting C. it is self-regulating D. all are correct
ANSWER: D
71. When a closed-loop system is used to maintain
physical position it is referred as A. gyro system B. feedback system C. servo system D. differential system
ANSWER: C
72. In closed-loop system, what do you call the difference in the measured value and the set value or desired value?
A. error B. differential voltage C. potential difference D. threshold
ANSWER: A
73. Error signal in closed-system is also known as A. difference signal B. deviation C. system deviation D. all are correct
ANSWER: D
74. In a closed-loop control system, when the error signal is zero the system is at
A. null B. saturation C. cut-off D. halt
ANSWER: A
75. The small error signal or system deviation where the system cannot correct anymore
A. threshold B. holding C. offset D. bias
ANSWER; C
76. A good closed-loop control system has the
following characteristics A. with very small offset signal or voltage B. quick response C. highly stable D. all are correct
ANSWER: D
77. In control system, the manner in which the controller reacts to an error is termed as
A. mode of operation B. type of operation C. mode of control D. reaction style
ANSWER: C
78. What are the general basic modes of control in control system?
A. On-Off B. Proportional C. Proportional plus integral D. Proportional plus derivative
ANSWER: D
79. Mode of control wherein the controller has only two operating states. This mode is also known as bang-bang control.
A. On-Off B. Proportional C. Proportional plus integral D. Proportional plus derivative
ANSWER: A
80. ____________ is a mode of control wherein the controller has a continuous range of possible position, not just two as in bang-bang control.
A. On-Off B. Proportional C. Proportional plus integral D. Proportional plus derivative
ANSWER: B
81. Proportional mode of control wherein the controller is not only considering the magnitude of the error signal but as well as the time that is has persisted.
A. On-Off B. Proportional C. Proportional plus integral * D. Proportional plus derivative
ANSWER: C
82. Proportional mode of control wherein the controller is not only considering the magnitude of the error signal but as well as its rate of change.
A. Proportional B. Proportional plus integral C. Proportional plus derivative * D. Proportional plus integral plus derivative
ANSWER: C
83. What is (are) being considered in Proportional plus Integral plus Derivative (PID) mode of control?
A. error signal magnitude B. error signal period of occurrence C. error signal rate of change D. all are considered *
ANSWER: D
84. If On-Off mode of control is the simplest, what is its opposite or the most complex?
A. Proportional B. Proportional plus integral C. Proportional plus derivative D. Proportional plus integral plus derivative
* ANSWER: D
85. The __________ are two of the most common
mechanical configuration of industrial robots. A. Spherical and pneumatic
B. Articulated arm and cylindrical * C. Spherical and hydraulic D. Jointed-arm and electric
ANSWER: B
86. One advantage of hydraulic actuator in industrial robots include _____________.
A. great force capability handling heavy loads *
B. lower operating cost than the other type C. low initial cost than the other type D. clean-no oil leaks
ANSWER: A
87. ____________ includes tow of the actuator type used in industrial robots.
A. Pneumatic and Jointed-arm B. Hydraulic and Pneumatic C. Electric and Spherical D. Hydraulic and Cylindrical
ANSWER: B
88. A system in which the precise movement of a large load is controlled by a relatively weak signal.
A. hydraulic B. electro C. synchro D. servo
ANSWER: D
89. A programmable, multifunction manipulator designed to move materials, parts, tools or specific devices.
A. Industrial robot B. Android C. Actuator D. End effector
ANSWER: A
90. The technology for automations A. avionics B. cryogenics C. cryotronics D. robotics
ANSWER: D
91. What is(are) the common mechanical configurations for industrial robots?
A. articulated-arm or jointed-arm B. spherical configuration C. cylindrical configuration D. all of these
ANSWER: D
92. The number of axis a robot is free to move is called
A. freedom axis B. degrees of freedom C. movement degrees D. mechanical axis
ANSWER: B
93. Actuators used in industrial robots A. electric motors B. fluid motors C. fluid cylinders D. all of these are correct
ANSWER: D
94. Which of the actuators that has the greatest force capability?
A. electric B. hydraulic fluid C. pneumatic D. magnetic
ANSWER: B
95. Actuator that requires the highest initial cost: A. electric B. hydraulic C. pneumatic D. magnetic
ANSWER: B
96. Robot actuator that has the highest operating cost:
A. electric B. hydraulic C. pneumatic D. magnetic
ANSWER: B
97. The most messy robot actuator: A. electric B. hydraulic C. pneumatic D. magnetic
ANSWER: B
98. Advantages of electric actuators:
A. Lower initial cost than either hydraulic or pneumatic
B. Much lower operating cost than hydraulic
C. Accurate positioning and good velocity control
D. All of these are correct ANSWER: D
99. Advantages of pneumatic actuators:
A. lower initial and operating cost than hydraulic actuators
B. Clean, no oil leaks C. Quick response D. All are correct
ANSWER: D
100. Advantages of hydraulic actuators A. Great holding strength when stopped B. Accurate positioning and good velocity
control
C. Intrinsically safe in flammable environment such as painting
D. All of these are correct ANSWER: D
101. Disadvantages of pneumatic actuators:
A. Weak force capability B. Not so much holding strength when
stopped as compared to hydraulic system
C. Accurate positioning and velocity control is impossible
D. All of these are correct ANSWER: D
102. Disadvantages of electric actuators in industrial
robots: A. Less force capability as compared to
hydraulic system B. Very little holding strength when
stopped which causes a heavy load to sag
C. Usually requires mechanical brakes D. All are correct
ANSWER: D
103. A robot software or program that produces only two-position motion for a given robot axis.
A. positive-stop B. point-to-point C. continuous-path D. hard interrupt
ANSWER: A
104. A robot program that has the ability to move a robot to any position within the range but without specific path.
A. positive-stop program
B. point-to-point program C. continuous path program D. compound program
ANSWER: B
105. A robot program that has the ability to move a robot to any position within the range with specific path.
A. positive-stop program B. point-to-point program C. continuous path program D. compound program
ANSWER: C
106. When a robot moves on several axis at the same time, it is to have
A. intrinsic motion B. extrinsic motion C. compound motion D. universal motion
ANSWER: C
107. In robotics, SCARA means:
A. Selective Compliant Articulated Robot Arm
B. Selective Compliant Assembly Robot Arm
C. Selective Computer-Actuated Robot Arm
D. A and B are correct ANSWER: D
108. SCARA Robots has how many axis of motion?
A. 2 B. 4 C. 6 D. 8
ANSWER: B
109. SCARA Robots are designed for what applications?
A. Machining B. Welding C. Assembling D. Handling heavy loads
ANSWER: C
110. Why is SCARA Robot attractive in industry? A. because it is relatively cheaper B. because it can carry very heavy loads C. because it has unlimited movement D. all of the above
ANSWER: A
TEST8.
1. An English mathematician who invented the slide rule in 1622.
A. Blaise Pascal B. Clifford Berry C. Charges Babage D. William Oughtred
ANSWER: D
2. Built a computer in 1946 at the Institute of Advance Study (IAS), Princeton, USA, that uses binary numbers and stores information.
A. Vannevar Bush B. John Van Neumann C. John Atannasoff
D. Clifford Berry ANSWER: B
3. An electronic device design to accept data
performs prescribed computational and logical operations at high speed and output the results of this operation.
A. Compiler B. Simulator C. Computer D. Digital machine
ANSWER: C
4. First commercial computer introduce in 1953 that uses valves.
A. IBM-1400 B. UNIVAC C. IBM-701 D. ENIAC
ANSWER: B
5. The first electronic computer and was completed in 1946.
A. ENIAC B. UNIVAC C. EDVAC D. Whirlwind I
ANSWER: A
6. ENIAC was developed at A. University of Pennsylvania B. Massachusetts Institute of Technology C. Cambridge University D. Bell Laboratories
ANSWER: A
7. Who constructed ENIAC and UNIVAC? A. William Oughtred B. Presper Eckert and John W. Mauchly C. John von Neumann D. William Oughtred and Jon von Neumann
ANSWER: B
8. ENIAC consist of how many vacuum tubes? A. 1,500 tubes
B. 3,575 tubes C. 13,575 tubes D. 18,000 tubes
ANSWER: D
9. ENIAC could perform _________ additions or up to _________ multiplications per second.
A. 1,000 / 100 B. 1,500 / 150 C. 3,000 / 300 D. 5,000 / 500
ANSWER: D
10. Whirlwind I, develop at Massachusetts Institute of Technology is capable of _________ operations per second.
A. 1,000 B. 5,000 C. 10,000 D. 20,000
ANSWER: D
11. Refers to the increased use of data conversion
circuits as a result of increased application. A. Op Amps B. Linear circuit C. Computers D. Digital equipment
ANSWER: C
12. What is a group of circuits that provides timing and signals to all operations in the computer?
A. Output unit B. Memory unit C. Control unit D. Input unit
ANSWER: C
13. Refers to the part of computer that performs mathematical operations.
A. CPU B. Flip-flop C. Assembly language D. ALU
ANSWER: D
14. What does ALU which carries arithmetic and logic operations process?
A. Binary coded decimal B. Hexadecimal numbers C. Octal numbers D. Binary numbers
ANSWER: D
15. What is the smallest part of a computer language?
A. binary B. byte C. bit D. word
ANSWER: C
16. A digital word consisting of only four bits is
called a A. dibit B. quad C. pixel D. nibble
ANSWER: D
17. Electronics methodology in solving application problems using circuits, in which there are only two possible voltage levels.
A. digital electronics B. switching techniques C. state diagramming D. bistable electronics
ANSWER: A
18. In digital electronics, there are mainly two possible voltage levels and these make _____ number system to be useful in its analysis.
A. binary B. octal
C. hexadecimal D. all of the above
ANSWER: A
19. 1 and 0 in binary number system are used to represent the two different voltage levels or logic levels in digital circuits. However, in most applications, a long string of 1’s and 0’s occur, and makes the data presentation “nasty”. To condense this long string of 1’s and 0’s, the ___________ number system is (are) also used.
A. octal B. decimal C. hexadecimal D. all of the above
ANSWER: D
20. How many symbols are used in octal digital number system?
A. 16 B. 4 C. 8 D. 2
ANSWER: C
21. How many symbols does hexadecimal digital number system used?
A. 16 B. 4 C. 8 D. 32
ANSWER: A
22. What is the equivalent of decimal number 11 in binary?
A. 1101 B. 1110 C. 1111
D. 1011 ANSWER: D
23. Which of the following is not used in hexadecimal
digital symbols? A. A B. C C. H D. F
ANSWER: C
24. What is the equivalent of decimal 7 in octal? A. 21 B. 49 C. 7 D. 14
ANSWER: C
25. The decimal 36020 is equivalent to hexadecimal ___________.
A. 8CB4 B. 88BC C. 8BC8
D. 884C ANSWER: A
26. What is the equivalent of decimal 14 in binary?
A. 1110 B. 1011 C. 1101 D. 1111
ANSWER: A
27. The code 1011 in BCD is A. 24 B. Letter A C. 11 D. Invalid
ANSWER: D
28. Conversion from binary to octal number system needs a grouping of bits by
A. Two B. Three C. Four D. Five
ANSWER: B
29. Convert the given binary number 1010011.01 to octal system.
A. 511.1 B. 511.2 C. 123.1 D. 123.2
ANSWER: D
30. What is the hexadecimal equivalent of the binary number 1010011.01?
A. 53.4 B. 53.1 C. A6.1
D. A6.4 ANSWER: A
31. The most practical way of converting
hexadecimal numbers to binary is to give each number its _________ equivalent bits.
A. Two B. Three C. Four D. Five
ANSWER: C
32. The binary equivalent of the hexadecimal number ECE.5
A. 1110 1100 1110.0101 B. 1110 1100 1110.101 C. 1101 1100 1101.101 D. 1101 1100 1101.0101
ANSWER: A
33. Convert (1111 1111 1111 1111)2 to decimal number.
A. 32 767
B. 32 768 C. 65 535 D. 65 536
ANSWER: C
34. Find the sum of binary number 1010 and 0011. A. 1021 B. 1101 C. 1011 D. 1111
ANSWER: B
35. Get the sum of (110.1101)2 and (11.01)2. A. 1010.0101 B. 1010.0001 C. 1101.0101 D. 0111.1010
ANSWER: B
36. What is the difference between the given binary numbers, 110.1101 and 11.01?
A. 110.0000 B. 111.1010 C. 11.1010 D. 11.1001
ANSWER: D
37. Find the radix-minus one complement of (110.1101)2.
A. 111.0010 B. 010.0011 C. 1.001 D. 001.0010
ANSWER: D
38. Give the true complements of (1101.1100)2. A. 0010.0011 B. 10.0011
C. 10.01 D. 0010.0100
ANSWER: D
39. Mathematics used in expressing, analyzing, and designing of digital electronic circuits.
A. Boolean algebra B. Numerical methods C. Statistical approach D. Logical mathematics
ANSWER: A
40. Method(s) used in simplifying Boolean algebra. A. Karnaugh map B. Map-entered variable technique C. Quine-McCluskey tabular method D. All of the above
ANSWER: D
41. Karnaugh map is the most commonly used method in simplifying Boolean expression or logical functions. In this method only 1’s and 0’s are entered into the table, while ________
includes variables into the table. A. Boolean algebra B. Map-entered variable technique C. Superposition method D. Quine-McCluskey tabular method
ANSWER: B
42. A suitable method in simplifying Boolean expression when the system deals with more than six variables.
A. Boolean algebra B. Karnaugh map C. Map-entered variable technique D. Quine-McCluskey tabular method
ANSWER: D
43. What level is used to represent logic 1 in a negative logic circuit?
A. negative transition level B. low level C. positive transition level D. high level
ANSWER: B
44. What level is used to represent logic “0” in a negative logic circuit?
A. high level B. low level C. negative transition level D. positive transition level
ANSWER: A
45. _________ is a gate which has two or more low inputs signals to get a low output.
A. AND B. Inverter C. OR D. NAND
ANSWER: C
46. What is the logic circuit having two or more inputs but only output, with high output of any or all inputs are high, with low output only if all inputs are low?
A. AND gate B. OR gate C. NOR gate D. NAND gate
ANSWER: B
47. A logic gate whose output is HIGH when a single HIGH at its input is present.
A. OR gate B. NOR gate C. AND gate D. NAND gate
ANSWER: A
48. An output of logic zero can be generated by what logic gate(s) if all inputs are zero?
A. OR gate
B. AND gate C. NOR gate D. NAND gate
ANSWER: A
49. Logic gate that generates an output of logic zero if and only if all inputs are zero.
A. OR gate B. AND gate C. NOR gate D. NAND gate
ANSWER: A
50. A solid state device which only gives a “1” output if all inputs are also “1” is called
A. an AND gate B. a NAND gate C. a NOR gate D. an OR gate
ANSWER: A
51. Only when all inputs are logic one that this gate can delver an output of logic one.
A. NOR gate B. AND gate C. NAND gate D. XOR gate
ANSWER: B
52. A solid state logical device which only gives a “1” output if all inputs are “0” is called a _________ gate.
A. NOT B. NOR C. NAND D. OR
ANSWER: B
53. To cause a three-state buffer to output 0-1 levels, the following must be true:
A. The output enable must be false B. The output enable must be true C. The information must have been stored
in the buffer D. The signal OE must be at logic 1
ANSWER: D
54. The rapidly flashing logic probe tip tells you that the logic node being probe
A. Has rapidly changing logic activity B. Is struck C. Is at an illegal logic level D. Has an unstable logic activity
ANSWER: A
55. ______________ is a single bit comparator. A. Wired OR B. Exclusive OR C. NOR gate D. Exclusive NOR
ANSWER: D
56. _____________ refers to the class of logic
circuit containing flip-flops. A. Combinational B. Sequential C. Linear D. Feedback
ANSWER: B
57. What is the counter that follows the binary sequence?
A. Binary counter B. Simplex counter C. Shift counter D. Decimal counter
ANSWER: A
58. What logic circuit is analogous to a single pole mechanical selector switch?
A. Decoder B. Encoder C. Multiplexer D. Exclusive OR
ANSWER: C
59. An encoder is an MSI (medium-scale-integrated) circuit that
A. Provides an output code that corresponds to which of a set of input line is true
B. Provides a storage of a certain number of binary bits
C. Selects a given output based on binary input code
D. Provides for delivering one of two or more inputs to an output
ANSWER: A
60. _____________ is called the time sharing of one line with multiplex signals.
A. Simultaneous transmission B. Bi-directional C. Relay D. Multiplexing
ANSWER: D
61. Data selector is also called A. Encoder B. Decoder C. Multiplexer D. Demultiplexer
ANSWER: C
62. _____________ refers to a function of a decade counter digital IC.
A. Provides one output pulse for every 10 inputs pulses
B. Adding two decimal numbers C. Producing 10 output pulses for every 1
pulse D. Decoding a decimal number for display
on seven-segment ANSWER: A
63. ___________ refers to BCD counter:
A. Decade counter B. Shift register C. Frequency divider D. Binary counter
ANSWER: A
64. In a system with MOS devices, the main bus loading factor is likely to be
A. Resistive B. Current C. Capacitive D. Static charge
ANSWER: C
65. When a logic circuit rejects an unwanted signal, this is termed as ___________.
A. Logic levels B. Noise margin C. Power consumption D. Propagation delay
ANSWER: B
66. Speed of a logic circuit is normally expressed as _________.
A. Logic levels B. Speed immunity C. Propagation delay D. Power consumption
ANSWER: C
67. What is a multi-wire connection between digital circuits?
A. Bus B. Wire wrap
C. Multiplexed cable D. Cable ribbon
ANSWER: A
68. What is the process used to describe analog-to-digital conversion?
A. Binarize B. Linearize C. Digitize D. Analogize
ANSWER: C
69. What is the process of converting multiple analog input signals sequentially to digital output?
A. Time division multiplexing B. Analog to digital conversion C. Space division multiplexing D. Pulse code modulation
ANSWER: A
70. What do you call a circuit that changes pure binary code into ASCII?
A. Decoder B. Encoder C. Demultiplexer D. Code converter
ANSWER: D
71. The output pulses of the logic pulser _________. A. Can damage logic circuits B. Are too many for the logic probe to
respond to C. Can only force high nodes to low D. Can be used to overdrive logic nodes
high or low ANSWER: D
72. Circuits used to implement Boolean expression
or equations. A. Logic gates/circuits B. Digital circuits C. Binary circuits D. All of the above
ANSWER: D
73. Logic gate whose output is HIGH when one or all of its inputs is LOW.
A. OR gate B. NOR gate C. AND gate D. NAND gate
ANSWER: D
74. What logic gate that generates an output of logic zero (LOW) only when all its inputs are logic one (HIGH)?
A. OR gate B. NOR gate C. AND gate D. NAND gate
ANSWER: D
75. Only when all inputs are LOW thus, this logic gate produces an output of HIGH.
A. NOR gate B. NAND gate C. AND gate D. NOR and NAND
ANSWER: A
76. A logic gate whose output is logic zero every time one of its inputs goes to logic one.
A. NOR gate B. NAND gate C. XOR gate D. A and C
ANSWER: A
77. Gate with HIGH output level every time one of its inputs goes LOW.
A. NOR gate B. NAND gate C. XNOR gate
D. B and C ANSWER: B
78. What logic gate that gives an output of logic one
if there is an odd number of 1’s at the input? A. NOR gate B. NAND gate C. XOR gate D. XNOR gate
ANSWER: C
79. Logic gate that gives a HIGH output when the input has an even number of 1’s.
A. NOR B. NAND C. XOR D. XNOR
ANSWER: D
80. A circuit that converts the input logic level to its complement.
A. Inverter B. NOR gate with all inputs tied C. NAND gate with all inputs tied D. All of the above
ANSWER: D
81. If the fan out of a logic gate is not enough, a/an ___________ should be used.
A. Inverter B. Amplifier C. Buffer D. Isolator
ANSWER: C
82. A buffer multiplies the number of gates a certain output can drive, and this can also be used as a/an
A. Voltage follower B. Current amplifier C. Isolator D. All of the above are correct
ANSWER: D
83. Is considered as a controlled inverter. A. XOR B. NOR C. NAND D. AND
ANSWER: A
84. A logic gate that can be wired to function like any other gate.
A. International gate B. Flexible gate C. Variable gate D. Universal gate
ANSWER: D
85. Known as universal gates. A. OR and AND
B. AND and NAND C. OR and NOR D. NOR and NAND
ANSWER: D
86. How many NAND-gates are needed to have an AND function?
A. 2 B. 3 C. 4 D. 5
ANSWER: A
87. The number of NAND-gates needed to form an OT-gate.
A. 2 B. 3 C. 4 D. 5
ANSWER: B
88. OR function can be achieved by suing how many NOR gates?
A. 2 B. 3 C. 4 D. 5
ANSWER: A
89. Which of the following is the probable output if all inputs of a TTL gate are binary 1?
A. Determinable B. Binary 0 C. Binary 1 D. Indeterminate
ANSWER: B
90. Logic devices are broadly divided or categorized into two families, bipolar and MOS. What are the examples of bipolar?
A. RTL and DTL B. IIL and ECL C. TTL and HLDTL D. All of the above
ANSWER: D
91. CMOS, NMOS, and PMOS belong to MOS family, what is (are) the significance of these devices?
A. They have lower power dissipation than bipolar devices
B. They are generally slower than bipolar devices
C. They are most sensitive to electrostatic D. All of the above
ANSWER: D
92. Refers to the ability of logic circuit it withstand noise superimposed on its input signal.
A. LOW noise immunity B. HIGH noise immunity
C. Noise immunity D. Noise figure
ANSWER: C
93. The number of logic gates of the same family that can be connected to the input of a particular gate without degrading the circuit performance.
A. Fan-in B. Fan-out C. Input-drive D. Input noise immunity
ANSWER: A
94. Refers to the number of logic gate of the same family that can be driven by a single output of a particular logic gate.
A. Output drive B. Output noise margin C. Fan-in D. Fan-out
ANSWER: D
95. A bipolar logic family that uses resistors as its input circuit.
A. RTL B. DTL C. ECL D. TTL
ANSWER: A
96. Logic family that uses diodes and transistors as its circuit elements. This logic family is more resistant to noise than RTL.
A. DTL B. TTL C. ECL D. I2L or IIL
ANSWER: A
97. A logic circuit family with a supply voltage of 25
V, and are generally used in industry where machinery causes electrical noise and large power line transients to occur.
A. HLDTL B. 74HXX C. NMOS D. CMOS
ANSWER: A
98. A variation of transistor-transistor-logic (TTL) wherein transistor’s base and collector junctions are clamped with a Schottky diode.
A. ECL B. STTL C. I2L D. CML
ANSWER: B
99. In a transistor-transistor logic (TTL), if the base collector junction of a transistor is clamped with a Schottky diode it becomes Schottky TTL. What
is the significance of having this diode? A. It increases the switching speed B. It decreases the power dissipation C. It increases the noise margin D. It increases the fan-out
ANSWER: A
100. Which of the bipolar logic circuits is the fastest? A. TTL B. STTL C. SCTL D. ECL
ANSWER: D
101. Other name of emitter-coupled logic (ECL). A. CML B. CSL C. NSL D. All of the above
ANSWER: D
102. Of all bipolar logic families, TTL is widely used. What do you think is (are) the reason(s) why?
A. Its speed is just enough for most applications
B. Its power consumption/dissipation is manageable
C. It has a good noise immunity D. All of the above
ANSWER: D
103. Of the MOS logic family, which is the fastest? A. PMOS B. NMOS C. CMOS D. VMOS
ANSWER: C
104. PMOS are generally supplied with a voltage up to A. 5.5 V B. 12 V C. 15 V D. 24 V
ANSWER: D
105. CMOS are normally supplied a voltage up to what value?
A. 5.5 V B. 12 V C. 15 V D. 24 V
ANSWER: C
106. PMOS and CMOS have normally different supply requirements. However, both can be operated from the same power supply provided it should be up to the CMOS limitation (15 V). CMOS output can drive directly PMOS inputs, but not PMOS’s output to CMOS’s input. How do you interface PMOS to CMOS?
A. By providing a pull-down resistor at the
interconnection (PMOS output to CMOS input)
B. By providing a pull-up resistor at the interface
C. By inserting a series limiting resistor between PMOS output and CMOS input
D. By interfacing through an open-collector transistor configuration
ANSWER: A
107. NMOS can be interfaced to CMOS by providing a A. Pull-up resistor B. Pull-down resistor C. Limiting resistor D. Coupling capacitor
ANSWER: A
108. A digital IC whose output transistor has no internal pull-up resistor.
A. Open-collector configuration B. Open-emitter configuration C. Totem-pole output D. Tri-sate output
ANSWER: A
109. In digital ICs, such as buffers and registers, what output configuration is used if they are intended for “busing”?
A. Totem-pole B. Tri-state output C. Complementary D. Open-collector
ANSWER: B
110. The output configuration of most CMOS ICs. A. Totem-pole B. Open-source C. Darlington
D. Complementary ANSWER: D
111. In TTL ICs, which input configurations gives a
high-input impedance at both logic states (HIGH and LOW state)?
A. MET B. Input with kicker transistor C. Diode cluster input D. Substrate PNP input
ANSWER: D
112. What is the purpose of the internal clamping diodes at the input of a logic circuit?
A. To minimize negative ringing effects B. To minimize positive ringing effects C. To regulate the input signal D. To protect reverse-polarity connection
ANSWER: A
113. In TTL ICs with more than one gate available, sometimes not all gates are used. How ill you handle these unused gates?
A. Force the output to go LOW B. Force the output to go HIGH C. Provide pull-down resistors to all inputs D. Provide all inputs with pull-up resistors
ANSWER: B
114. How ill you handle unused inputs in a logic gate/ logic IC?
A. Leave them floating B. Pull them down C. Pull them up D. Pull them down or up, depending on
circuit function ANSWER: D
115. What is the memory element used in clocked
sequential logic circuit? A. Gates B. Flip-flop C. Static-RAM D. Read-only memory
ANSWER: B
116. A static memory will store information A. As long as power is applied to the
memory B. Even when power is not applied to the
memory C. As long as power is applied and the
memory is refreshed periodically D. When power is applied at regular
intervals ANSWER: B
117. What is the reason why more cells can be stored
in a given area with dynamic cells? A. They consume less power B. They are similar
C. They are larger D. They travel faster
ANSWER: B
118. A ______________ is a solid state memory device, which depends on the magnetic polarization of domains, usually in a garnet type material.
A. Magnetic disk B. Magnetic core C. Magnetic bubble D. Magnetic drum
ANSWER: C
119. ______________ are non-semiconductor devices still used in digital memories.
A. Gates B. Flip-flops C. Relay D. Magnetic cores
ANSWER: D
120. The density of data recorded on magnetic tape is
measured in A. Bit stuffing rate B. Bit error rate C. Bits per inch D. Bits per second
ANSWER: C
121. A memory circuit that has 9 address inputs has how many storage locations?
A. 1024 B. 256 C. 512 D. Not determined by sets of input
ANSWER: C
122. Clock periods are measured from ___________. A. The high level to the low level B. The low level to the high level C. Similar points on the clock waveform D. The clock pulse at 50% of its low or
high levels ANSWER: C
123. Determine which item is not a storage device.
A. Card readers B. CD-ROM C. Diskettes D. Magnetic tape
ANSWER: A
124. What is the function of flip-flop as logic element? A. Stores binary data B. Generates clock signal C. Relay data D. Makes decision
ANSWER: A
125. _____________ is not a type of flip-flop.
A. RS B. Latch C. D D. Register
ANSWER: D
126. What is the higher voltage level in digital gates and flip-flop circuits?
A. Yes or One B. One or Zero C. Zero or No D. Yes or No
ANSWER: A
127. _____________ is a byte data stored in a memory location.
A. 8 bits B. Character C. 4 bits D. Memory word
ANSWER: D
128. _____________ is called retrieving data from
memory. A. Accessing B. Getting C. Encoding D. Reading
ANSWER: A
129. ____________ can erase EPROMS. A. Applying a 21-volt pulse B. Applying ultraviolet rays C. Turning off the power D. Blowing fuse
ANSWER: B
130. ___________ is a segment register which normalcy access variables in the program.
A. Extra B. Stack C. Data D. Code
ANSWER: B
131. ____________ is a storage device used to accommodate a difference in rate of flow of data or time of occurrence of events when transmitting from one device to another.
A. Accumulator B. Buffer C. Modem D. Register
ANSWER: B
132. _____________ is a device that stay on once triggered and store one or two conditions as a digital circuit.
A. Gate B. Latch C. Integrator
D. Oscillator ANSWER: B
133. The typical number of bits per dynamic memory
location is A. 1 B. 8 C. 2 D. 16
ANSWER: A
134. ______________ is an output applied to Read Only Memory (ROM).
A. Multiplexer B. Address C. Input code D. Data
ANSWER: B
135. ____________ is a kind of memory where only manufacture can store program and has s group of memory locations each permanently storing a word.
A. ROM B. SOS memory C. RAM D. Hard memory
ANSWER: A
136. In shift registers made up of several flip-flops, the clock signal indicates ________.
A. A bit of information stored in flip-flop B. Information of time C. What time is it D. When to shift a bit of data from input of
the flip-flop to the output ANSWER: D
137. What do you call the duration within it takes to
read the content of a memory location after it has been addressed?
A. Execution time B. Data rate C. Cycle time D. Access time
ANSWER: D
138. A static memory generally contains A. Row and column decoders B. No decoders C. Row decoders D. Column decoders
ANSWER: A
139. ___________ is called a memory device which holds fixed set of data in a circuit.
A. RAM B. Register C. Logic D. ROM
ANSWER: D
140. An interval required to address and read out
memory word. A. Propagation delay B. Pulse duration C. Setting time D. Access time
ANSWER: D
141. ___________ refers to a circuit that stores pulses and produces an output pulse when specified numbers of pulses are stored.
A. Counter B. Register C. Flip-flop D. Buffer
ANSWER: A
142. A dynamic memory will store information A. As long as power is applied to the
memory B. As long as power is applied and the
memory is refreshed periodically
C. Even when power is not applied to the memory
D. When power is applied at regular interval
ANSWER: B
143. Several gates combined to form the basic memory element.
A. Multivibrator B. Register C. ROM D. Flip-flop
ANSWER: D
144. An RS flip-flop constructed from NOR-gates would have an undefined output when the inputs R/S combinations are
A. LOW / LOW B. LOW / HIGH C. HIGH / LOW D. HIGH / HIGH
ANSWER: D
145. When a flip-flop is constructed from two NAND-gates, its output will be undefined if the R/S inputs are
A. LOW / LOW B. LOW / HIGH C. HIGH / LOW D. HIGH / HIGH
ANSWER: A
146. A flip-flop whose output is always the same as its input. This is sometimes used as delay element.
A. RS flip-flop B. D flip-flop C. T flip-flop
D. JK flip-flop ANSWER: B
147. Flip-flop that changes state every time the input
is triggered. A. RS flip-flop B. Master slave flip-flop C. T flip-flop D. JK flip-flop
ANSWER: C
148. Flip-flop arrangement, such that the first receives its input on the positive edge of a clock pulse, and the other receives its input from the output of the first during the negative edge of the same pulse.
A. Clocked RS flip-flop B. Clocked JK flip-flop C. Cascaded flip-flop D. Master/slave flip-flop
ANSWER: D
149. Combination of flip-flop, arranged so that they
can be triggered at the same time. A. Clocked flip-flop B. Delayed flip-flop C. Sequential flip-flop D. Asynchronous flip-flop
ANSWER: A
150. A flip-flop without an undefined output state condition whatever the input combination is
A. JK flip-flop B. T flip-flop C. D flip-flop D. All of the above
ANSWER: D
151. Group of flip-flops used to store more bits. A. Register B. ROM C. PROM D. All of the above
ANSWER: A
152. Sequential access digital memory uses what storage circuit?
A. Parallel register B. Shift register C. Dynamic RAM D. EEPROM
ANSWER: B
153. Memory whose contents are lost when, electrical power is removed.
A. Nonvolatile B. Temporary C. Dynamic D. Volatile
ANSWER: D
154. One of the following can program PROMs. A. Biasing bipolar transistor B. Blowing fuse C. Effusing input D. Charging a gate
ANSWER: B
155. Type of memory wherein the data are permanently stored. Usually the storing of data is done during manufacturing of the component.
A. ROM B. PROM C. EPROM D. EEPROM
ANSWER: A
156. A semiconductor memory device in which data can be stored after fabrications.
A. PROM B. EPROM C. EEPROM D. All of the above
ANSWER: D
157. A type of ROM that allows data to be written into
the device by a programmer. After it has been programmed it cannot be reprogrammed again.
A. PROM B. EPROM C. EEPROM D. A and B above
ANSWER: A
158. What memory device that can be programmed, and reprogrammed after the old programs are erased usually by an ultraviolet light?
A. EEPROM B. EPROM C. RPROM D. B and C
ANSWER: D
159. A variation of PROM, wherein its stored data can be erased by electrical signal instead of ultraviolet light.
A. EEPROM B. Dynamic ROM C. RAM D. EEPROM and dynamic RAM
ANSWER: A
160. A nonvolatile memory A. ROM B. PROM and RPROM C. EPROM and EEPROM D. All are correct
ANSWER: D
161. What is the time interval to undertake a refresh operation in a typical dynamic RAM?
A. 2 ms
B. 200 ms C. 50 microsec. D. 22 microsec.
ANSWER: A
162. Semiconductor-based, volatile data storage device that can be written and read randomly.
A. RAM B. PROM C. EPROM D. EEPROM
ANSWER: A
163. Random access memory that needs recharging of capacitors.
A. SRAM B. DRAM C. Dynamic storage D. A and B
ANSWER: B
164. Dynamic RAM (DRAM) uses capacitor as its data storage element, while static RAM (SRAM) uses
what? A. Inductor B. Magnet C. Register D. Flip-flop
ANSWER: D
165. Type of memory that is formed by a series of magnetic bubbles at the substrate.
A. Magnetic disk B. Bubble sort C. Bubble chart D. Bubble memory
ANSWER: D
166. Non-semiconductor digital memory device. A. Magnetic core B. Magnetic domain C. Saturable core D. Ferromagnetic domain
ANSWER: A
167. A hardware used to program a PROM. A. Microcomputer B. Data loader C. Encoder D. PROM programmer
ANSWER: D
168. Computer hardware device constructed to perform shifting of its contained data.
A. Parallel register B. Serial to parallel register C. Shift register D. ALU
ANSWER: C
169. Register wherein data can be serially inputted, while the output can be retrieved in parallel manner.
A. Serial to parallel register B. Parallel storage C. Parallel to serial register D. Serial register
ANSWER: A
170. Digital device similar to that of a ROM and whose internal connections of logic arrays can be programmed by passing high current through fusible links.
A. PLA B. PAL C. APL D. A and B
ANSWER: D
171. What is the difference between a read only memory (ROM) and a programmable logic array (PLA)?
A. All input combinations of a ROM
produce an output, while in a PLA, some input combinations do not affect the output.
B. Only the OR-functions in a ROM are programmable, whereas in a PLA, both OR and AND-functions are programmable.
C. In ROM, all the possible states must be programmed, while not all for a PLA.
D. All of the above ANSWER: D
172. The difference between a programmable logic
array (PLA) and a programmable array logic (PAL) is that,
A. With PLA, only OR-gates are programmable, whereas both OR and AND gates are programmable in PAL
B. With PLA, both OR and AND-gates are programmable, while in PAL only OR-gate is programmable
C. With PLA, both OR and AND-gates are programmable, while in PAL, only AND-gate is programmable
D. Only AND-gate is programmable with PLA, whereas both OR and AND-gates are programmable for PAL
ANSWER: C
173. A circuit used for selecting a single output from multiple inputs.
A. Universal logic module (ULM) B. Demultiplexer C. Tri-state D. Logic array
ANSWER: A 174. Another name for universal logic module (ULM)
A. Multiplexer
B. Decoder C. Coder D. Shift register
ANSWER: A
175. A device/circuit used to separate two or more signals from one line.
A. Decoder B. Demodulation C. Demodifier D. Demultiplexer
ANSWER: D
176. An electronic counter in which bistable units are cascaded to form a loop.
A. Ring counter B. Twisted ring counter C. UP/DOWN counter D. Bistable counter
ANSWER: A
177. What is formed when the complemented output of the last stage of a shift register is fed back to
the input of the first stage? A. Ring counter B. Twisted ring counter C. Decade counter D. UP/DOWN counter
ANSWER: B
178. A digital circuit that produces logic 1 output pulse for every 10 input pulses.
A. Decade scaler B. Divider C. Chopper D. Multiplexer
ANSWER: A
179. Binary codes are converted into ASCII by what circuit?
A. Decoder B. Demultiplexer C. Degenerator D. Code converter
ANSWER: D
180. The technical term used when signals are converted from analog-to-digital.
A. Digitize B. Quantize C. Coded D. All of the above
ANSWER: A
181. ________________ is a sequence of instructions that tells the computer machine on how available data shall be processed.
A. Program B. RAM C. Command D. Flowchart
ANSWER: A
182. Diagram showing procedures that are followed, and actions taken is called
A. Functional block diagram B. Circuit diagram C. Flow chart D. Schematic diagram
ANSWER: C
183. What is the medium of communication with a computer where programs are written in mnemonics?
A. Assembly language B. High level language C. Machine language D. Low-level language
ANSWER: C
184. A _________ a program which converts instruction written in a source language into machine code, which can be read and acted upon by the computer.
A. Source code B. Assembler C. Application software D. Compiler
ANSWER: B
185. A detailed step by step set of direction telling a computer exactly how to proceed to solve a specific problem or process as specific task.
A. Sequence B. Flow chart C. Computer program D. Process
ANSWER: C
186. What is a program that translated English-like word of high-level language into the machine language of a computer?
A. Compiler B. Assembler C. Monitor program D. Interpreter
ANSWER: A
187. ___________ is a software that converts a high level language program into machine or assembly language program.
A. ALU B. Cross-assembler C. Compiler D. CPU
ANSWER: C
188. The purpose of the fetch cycle in a computer is to ____________.
A. Obtain instruction B. Obtain input data C. Obtain memory data
D. Implement a specific operation ANSWER: A
189. _____________ refers to a program that
translates and then immediately executes statements in a high level language.
A. Interpreter B. Synchronous C. Interface D. Operating system
ANSWER: A
190. A _____________ is an instruction in a source language that is to be replaced by a defined sequence of instructions in the same source language.
A. Statement B. Source code C. Mnemonic D. Macro-instruction
ANSWER: D
191. A very high-dense and probably the most
versatile integrated circuit used in digital electronics. It is known to function as the central processing unit of most computer applications.
A. Microcomputer B. Micro-integrated C. Macro-integrated D. Microprocessor
ANSWER: D
192. The smallest computer in terms of physical size A. Microcomputer B. Minicomputer C. Mainframe D. Host computer
ANSWER: A
193. A logic/digital circuit that generates an output code for every input signal.
A. Enhancer B. Compressor C. Encoder D. Decoder
ANSWER: C
194. What code that gives each digit of a decimal number with a corresponding binary equivalent?
A. Binary code B. Gray code C. ASCII D. Binary coded decimal
ANSWER: D
195. Which of the code below is considered as minimum-change code?
A. Gray code B. ASCII C. BCD D. ARINC
ANSWER: A
196. A 7-bit alphanumeric code that is widely used A. Gray code B. ASCII C. BCD D. ARINC
ANSWER: B
197. The op-code of a computer instruction A. Mnemonic B. Bionic C. Operand D. Program
ANSWER: A
198. An instruction that causes the program to go another task.
A. FLIP B. SUB C. JUMP D. MOVE
ANSWER: C
199. An instruction that can move data from memory
to the accumulator. A. FETCH B. MOVE C. ACC D. LOAD
ANSWER: D
200. An instruction tat moves data from accumulator to the memory
A. FETCH B. MOVE C. STORE D. LOAD
ANSWER: C
201. Part of the instruction cycle where the instruction is moved from memory to the instruction register.
A. ACC B. FETCH C. MOVE D. CLI
ANSWER: B
202. An instruction, which means “clear the interrupt mask”.
A. ACC B. DEL C. CANCEL D. CLI
ANSWER: D
203. Refers to a condition wherein the result of an arithmetic operation is more negative than the capacity of the output register.
A. Error
B. Negative infinite C. Overflow D. Underflow
ANSWER: D
204. Refers to a condition wherein the result of an arithmetic operation is more than the capacity of the output register.
A. Error B. Infinite C. Overflow D. Underflow
ANSWER: C
205. Machine instructions represented by mnemonics is considered as
A. Machine language B. Personal language C. Assembly language D. Coded language
ANSWER: C
206. The first generation language of instruction, and
is considered as the most primitive instruction that can be given to a computer.
A. Machine language B. Assembly language C. COBOL D. 4GL
ANSWER: A
207. COBOL, FORTRAN, and ALGOL are examples of A. Machine language B. Assembly language C. High-level language D. 4GL
ANSWER: C
208. An advanced programming language, more advanced than high-level language.
A. Machine language B. Assembly language C. High-level language D. 4GL or 4th generation language
ANSWER: D
209. Translator from high-level program to machine instructions
A. Assembler B. Converter C. Encoder D. Compiler
ANSWER: D
210. Translates source program to object program A. Assembler B. Converter C. Encoder D. Compiler
ANSWER: D
211. Assemble language to machine language translator
A. Assembler B. Converter C. Compiler D. Transponder
ANSWER: A
212. A program in a programming language, as written by the programmer.
A. Source program B. Object program C. Machine program D. Original program
ANSWER: A
213. A source program can run in computer only after translation into a machine code by a compiler. This machine code is referred as the
A. Source program B. Object program C. Interpreter D. Mnemonic
ANSWER: B
214. A program that can read a source program in high-level language, translates, and executes the statement in one operation.
A. Mnemonic B. Object program C. Interpreter D. Assembler
ANSWER: C
215. A sequence of instructions or statements designed to tell the computer how to carry out a particular processing task.
A. Software B. Hardware C. Assembler D. Program
ANSWER: D
216. The instructions and data in a computer system is referred to as
A. Software B. Hardware C. Program D. CPU
ANSWER: A
217. Refers to digital interface in which data characteristics are individually synchronized and may be sent at a time.
A. Half-duplex B. Asynchronous C. Synchronous D. Simplex
ANSWER: B
218. A network facility used to connect individual similar network segments forming a larger extended network is called _________.
A. Routers B. Relays C. Repeaters D. Bridges
ANSWER: C
219. What is the circuit that detects bit error in binary characters?
A. Decoder B. Parity detector C. Server D. Comparator
ANSWER: B
220. A device that enables users to transmit computer data and fax messages along telephone lines
A. Converter B. Facsimile C. Demodulator D. Modem
ANSWER: D
221. What do you call the devices that allow computers to communicate with other computers through telephone lines or radio frequency?
A. Modems B. Disk C. Mouse D. Super computers
ANSWER: A
222. What network facility used to interconnect distinct networks physically?
A. Relays B. Routers C. Repeaters D. Bridges
ANSWER: D
223. Files in E-mail communication are send thru ____________.
A. Disk B. Mailbox C. Wires D. Attachment
ANSWER: D
224. The first recipient in E-mail communication. A. Host B. Mail box C. Computer D. Disk
ANSWER: A
225. The interconnections of computers, terminals, and other equipment.
A. Cluster B. Network
C. Cascading D. Bonding
ANSWER: B
226. A network classification that is usually built and owned by a single company or governmental organization.
A. Private data network B. Public data network C. Switched network D. Node
ANSWER: A
227. A network that is built and owned by a common carrier.
A. Public data network B. Private data network C. Leased line network D. Node
ANSWER: A
228. Network configuration that let computers share their resources.
A. Peer-to-peer network B. Hierarchical network C. Permanent virtual circuit D. Local Area Network
ANSWER: A
229. A computer network configuration that makes the host computer manages a network of dependent terminals.
A. Hierarchical network B. Peer-to-peer network C. Local Area Network D. Wide Area Network
ANSWER: A
230. A network switching that creates a dedicated temporary connection between computers in a network.
A. Circuit switching B. Message switching C. Packet switching D. Virtual switching
ANSWER: A
231. The component that provides control or supporting services for other computers, terminals, or devices in a network.
A. Host B. Communications controller C. Cluster controller D. Interface equipment
ANSWER: A
232. It is a type of computer networking technology that is used to connect computers that are located within the same room, building, or complex.
A. Internet
B. Intranet C. Local area network D. Wide area network
ANSWER: C
233. It is a fast computer with a large amount of secondary storage, to which all of the other computers in a network have access for data storage and retrieval.
A. Mainframe B. Maincomputer C. File server D. Workstation
ANSWER: C
234. It is also known as cooperative processing that involve using two or more networked computers to perform an application task.
A. Client computing B. Server computing C. Distributed processing D. Client/server computing
ANSWER: D
235. A type of server that allows multiple users to take advantage of a single printing device.
A. Printer server B. Client server C. Network server D. File server
ANSWER: A
236. This topology is the most efficient centralized network for a small company
A. Bus B. Ring C. Tree D. Star
ANSWER: D
237. It is the other term that is used to refer to a central device into which each node of a star network is directly connected.
A. Hub B. Central pointer C. Router D. Repeater
ANSWER: A
238. It is simply the term that is used to refer to an I/O device that relies entirely on the host computer for processing.
A. Keyboard B. Terminal C. Monitor D. Mouse
ANSWER: B
239. Workstations in a star network that can operate without storage devices.
A. Diskless B. Wireless
C. Disked D. Wired
ANSWER: A
240. A ___________ network requires that message travel around the ring to nthe desired destination.
A. Star B. Bus C. Tree D. Ring
ANSWER: D
241. Networks that transmit data across town using electromagnetic signals are called ____________.
A. LANs B. WANs C. MANs D. All of the above
ANSWER: C
242. The process of choosing a terminal on a network
to receive data is called _______. A. Polling B. Selection C. Contention D. Option
ANSWER: B
243. A microcomputer attached to a network requires a __________.
A. Dongle B. Network interface card C. RS-232 D. Software
ANSWER: B
244. To ___________ is to send a file to a remote computer
A. Upload B. Download C. Call D. Transmit
ANSWER: A
245. To ___________ is to receive a file from a remote computer.
A. Upload B. Download C. Call D. Transmit
ANSWER: B
246. It is term that is used to describe the conventions of how network components communicate with each other.
A. Network model B. Network layer C. Network topology D. Network protocol
ANSWER: D
247. It is term that is used to describe the form or the shape of a network.
A. Network model B. Network layer C. Network topology D. Network protocol
ANSWER: C
248. __________ is the process of asking each remote terminal, one at a time, if it has data to send.
A. Polling B. Selection C. Contention D. Option
ANSWER: A
249. __________ network topology has more than one level of host computer.
A. Star B. Bus
C. Hierarchical D. Ring
ANSWER: C
250. It describes its System Services Control Point (SSCP), Logical Units (LU), and Physical Units (PU) as network addressable units.
A. Internetworking B. Digital network architecture C. Open system interconnection D. Systems network architecture
ANSWER: D
251. Networks that include telecommunications are called __________.
A. LANs B. WANs C. MANs D. All of the above
ANSWER: B
252. A multi-network IBM token ring network is also a __________ network.
A. Star B. Bus C. Tree D. Mesh
ANSWER: A
253. Network topology, where stations are connected to a concentric ring through a ring interface unit (RIU).
A. Bus B. Mesh C. Token Ring D. Tree
ANSWER: C
254. A _________ will decide which route the message or messages should follow through the network.
A. Router B. Bridge C. Repeater D. Gateway
ANSWER: A
255. Used in connecting networks at different sites. A. Router B. bridge C. repeater D. gateway
ANSWER: B
256. Similar to a bridge, which connects networks at different sites, it connects networks with different protocols.
A. Router B. Bridge C. Gateway D. Repeater
ANSWER: C
257. Used to extend the length of a network or to expand the network.
A. Router B. Bridge C. Gateway D. Repeater
ANSWER: D
