MULTIPLE CHOICE QUESTIS IN

ELECTRONICS ENGINEERING

by

RONIE VILLAMOR

Encoded by:

VILLAMOR, Mara Mariz M.

1. What is the smallest element of a matter?

a. atom

b. molecule

c. crystal

d. wafer

2. 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

3. Approximate diameter of an atom

a. 10^-10 µµm

b. 10^-10 µm

c. 10^-10 mm

d. 10^-10 m

4. Known as the simplest type of atom

a. Hydrogen

b. Oxygen

c. Helium

d. Nitrogen

5. 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

6. 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

7. Protons are about ____ heavier than electrons

a. 1,800 times

b. Less than thrice

c. Less

d. Twice

8. 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

9. 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

10. It is composed of a series of energy levels containing the valence electrons

a. conduction band

b. forbidden band

c. sideband

d. valence band

11. Electrons at the conduction band are called

a. free electrons

b. valence electrons

c. deep state electrons

d. shallow state electrons

12. A good conductor has how many valence electrons?

a. 1

b. 2

c. 4

d. 8

13. 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.

14. A material that contains an abundance of free carrier is called

a. Insulator

b. Semi-insulator

c. Conductor

d. Semiconductor

15. 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

16. A solid, which has no defined crystal structure

a. Crystalline

b. Non-crystalline

c. Amorphous

d. Non-crystalline or Amorphous

17. Ideally, all atoms have the same number of positively charged protons and

negatively charged electrons, and is therefore as

a. Electrically neutral

b. Physically stable

c. Magnetically aligned

d. Technically rigid

18. A positive ion has

a. excess of electrons

b. excess of neutrons

c. lack of electrons

d. lack of protons

19. One Coulomb of charge has how many electrons?

a. 6.24 x 10^18 electrons

b. 6.24 x 10^19 electrons

c. 62.4 x 10^18 electrons

d. 62.4 x 10^19 electrons

20. One ampere is equal to how many electrons per second?

a. 1 x 10^18 electrons/sec.

b. 1 x 10^19 electrons/sec.

c. 6.25 x 10^18 electrons/sec.

d. 6.25 x 10^19 electrons/sec.

21. The greater the diameter of a wire, the ___ is the resistance.

a. greater

b. lesser

c. harder

d. bigger

22. A 100m long wire with a cross-sectional area A=10^-3 m^2 has a resistance of 10

ohms. Determine the resistivity of the wire.

a. 10^-2 ohms-m

b. 10^-3 ohms-m

c. 10^-4 ohms-m

d. 10^-5 ohms-m

23. The science of physical phenomena at very low temperature, approaching

absolute zero is called ___.

a. crytanalysis

b. cybernetics

c. temperature inversion

d. cryogenics

24. A wire has a resistance of 5 ohms at room temperature and a temperature

coefficient α =4 x 10^-3 / ºC, calculate the wire resistance at 75 ºC.

a. 8.925 ohms

b. 7.925 ohms

c. 6.925 ohms

d. 6.050 ohms

25. The temperature coefficient of resistance of a certain wire is known to be 0.004/

ºC at zero degree Celsius. What would be the temperature coefficient at room

temperature?

a. 0.00018/ºC

b. 0.00036/ºC

c. 0.00180/ºC

d. 0.00360/ºC

26. Find the change in coulombs of dielectric that has a positive charge of 14.5 x 10

to the 18the power protons.

a. 29 x 10 to the 16th

Coulombs

b. 14.5 x 10 to the 16th

Coulombs

c. 14.5 x10 to the 18th

Coulombs

d. 29 x 10 to the 18th

Coulombs

27. 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

28. Three charges of +5 C, -6 C and +7 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

29. 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.

30. Electric lines of force leave and enter the charge surface at what angle?

a. 15 º

b. 30 º

c. 45 º

d. 90 º

31. Electric flux is a/an ________ quantity.

a. scalar

b. vector

c. absolute

d. relative

32. 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/m^2

b. 2 C/m^2

c. 4 C/m^2

d. 6 C/m^2

33. 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 x10^-19 F/m

d. 36π x 10^-19 F/m

34. 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

35. Calculate the electric field intensity 10 cm from a charge Q=5nC.

a. 450 N/C

b. 900 N/C

c. 4.5 x 10^3 N/C

d. 9.0 x 10^3 N/C

36. 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 10^7 N/C

c. 1.8 x 10^8 N/C

d. Infinite

37. A charged body in free spaces produces 10-V potential at a distance 25 cm away.

What will be the potential at 50 cm away?

a. 5.0 Volts

b. 7.5 Volts

c. 10.0 Volts

d. 15.0 Volts

38. 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

39. Materials with permeability slightly less than that of free space.

a. diamagnetic

b. paramagnetic

c. ferromagnetic

d. antimagnetic

40. The unit of magnetic flux density in SI

a. Gauss

b. Weber

c. Maxwell

d. Tesla

41. A magnetic flux of 25,000 maxwell in an area of 5 sq. cm. Results in flux density

of

a. 5,000 Gauss (G)

b. 125,000 G

c. 5,000 Tesla (T)

d. 125,000 T

42. Calculate the flux density in Gauss (G) having a flux of 12,000 Mx through a

perpendicular area of 6 cm.

a. 200 G

b. 2,000 G

c. 7,200 G

d. 72,000 G

43. If the distance between the 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

44. Unit of permeability

a. Henry/meter (H/m)

b. Farad/meter (F/m)

c. Henry-meter (H-m)

d. Farad-meter (F-m)

45. The unit of permittivity

a. Henry/meter (H/m)

b. Farad/meter (F/m)

c. Henry-meter (H-m)

d. Farad-meter (F-m)

46. One Weber is equivalent to

a. 10^8 Maxwells

b. 10^6 Maxwells

c. 10^4 Maxwells

d. 10^2 Maxwells

47. Permeance is analogous to

a. Conductance

b. Resistance

c. Impedance

d. Elastance

48. The Oersted (Oe) is the same as

a. 1 Gb/cm

b. 1 Gb/m

c. 10 Gb/cm

d. 10 Gb/m

49. The unit of reluctance

a. Gilbert

b. Tesla

c. At/Wb

d. Gauss

50. Determine the ampere-turns when a 10V battery is connected across a solenoid

having 100 turns and a resistance of 5 ohms.

a. 50 At

b. 200 At

c. 100 At

d. 1,000 At

51. 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

52. 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

53. 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

54. What is meant by back EMF?

a. A voltage that is applied in the reverse direction

b. An EMF that is due 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

55. In electromagnetism, what law determines the amount of induced voltage?

a. Ampere’s law

b. Lenz’ law

c. Coulomb’s law

d. Faraday’s law

56. 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

57. _________ 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

58. 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%

59. Resistors with high value usually have lower wattage ratings because of

_________.

a. varying current

b. lower current

c. bigger size

d. high current

60. 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

61. If you need a 1.25 kilo ohms resistance and you only have resistors of 5 kilo

ohms, how many of these available resistors you should connect in parallel to get

a 1.25kilo ohms value?

a. 2

b. 3

c. 4

d. 5

62. _______ is used to store electrical energy in an electrostatic field?

a. A transformer

b. A battery

c. A capacitor

d. An inductor

63. What factors determine the capacitance of a capacitor?

a. Area of the plates, amount of charge in the plates and the dielectric

constant of the material between the plates

b. Area of the plates, voltage on the plates and 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 of the plates and the dielectric constant of the

material between the plates

64. 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. 4.372 picofarad

65. 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

66. 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

67. Two resistors, 10 ohms and 100 ohms are connected in parallel approximately,

what is the total resistance?

a. 10 ohms

b. 50 ohms

c. 90 ohms

d. 100 ohms

68. A shunt resistor is used to limit the load current to 0.5 A. If the load resistance is

100 ohms and the original current is 1 amp, what should be the value of the shunt

resistance?

a. 25 ohms

b. 50 ohms

c. 75 ohms

d. 100 ohms

69. Two resistors, R1=100 ohms and R2=200 ohms 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

70. A constant voltage source Vs=60 is delivering power to a series combination of

R1=100 ohms, R2=200 ohms and R3=300 ohms. Calculate the voltage drop

across R2.

a. 10 V

b. 20 V

c. 30 V

d. 40 V

71. 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

72. The power dissipated by a 10 ohms 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. 160 W

d. 250 W

73. 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

74. How many nodes are needed to completely analyze a circuit according to

Kirchoff’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

75. In a mesh, the algebraic sum of all the voltages and voltage drops is equal to zero

a. Superposition theorem

b. Norton’s law

c. Kirchoff’s first law

d. Kirchoff’s second law

76. 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. Kirchoff’s

77. A certain Thevenin equivalent circuit has parameters Rth=10 ohms and Vth=20V.

if this is converted to Norton’s equivalent circuit, Rn and In would be

a. 10 ohms and 2 A

b. 10 ohms and 4 A

c. 0.10 ohms and 2 A

d. 0.10 ohms and 4 A

78. Rn and In of a Norton’s equivalent circuit are known to be 100 ohms and 10 A

respectively. If a 400 ohms load is connected, it will have a load current of

a. 1 A

b. 2 A

c. 3 A

d. 4 A

79. 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

80. The return point in a circuit, where all voltage measurements are referred

a. node

b. junction

c. ground

d. loop

81. Three 100 ohms resistors are connected in 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 ohms

b. 75 ohms

c. 125 ohms

d. 150 ohms

82. Three resistors, R1=60 ohms, R2=80 ohms and R3=100 ohms are connected in

delta. If the network is to be transformed into star, what would be the value of the

resistor opposite to R2?

a. 25.0 ohms

b. 33.3 ohms

c. 45.0 ohms

d. 56.7 ohms

83. An alternating voltage of sine-wave form has a maximum voltage of 311 V. what

is its value at 225º?

a. 110 V

b. 220 V

c. -220 V

d. -110 V

84. If an alternating voltage has a magnitude of 10 V at 30º, what is its maximum

voltage?

a. 20 V

b. 30 V

c. 40 V

d. 50 V

85. What is the frequency of an alternating current, if it reaches 90º within 4.167 ms?

a. 20 Hz

b. 30 Hz

c. 50 Hz

d. 60 Hz

86. At what angle does an alternating voltage of cosine-wave form reaches its

negative peak?

a. 45º

b. 90º

c. 135º

d. 180º

87. 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

88. What do you mean by root-mean-squared (rms) voltage?

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

89. In a purely inductive circuit the current

a. Leads the voltage by 45º

b. Leads the voltage by 90º

c. Lags the voltage by 90º

d. Lags the voltage by 45º

90. 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 45º

b. Current lags the voltage by 45º

c. Current leads the voltage by 90º

d. Current lags the voltage by 90º

91. 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

92. A 220-volt, 60 Hz source is driving a series RL circuit. Determine the current in

the circuit if R=100 ohms and XL= 100 ohms.

a. 1.10 A(lagging)

b. 1.55 A(lagging)

c. 2.20 A(lagging)

d. 4.40 A(lagging)

93. 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 = Imax sin(120πt + 60)

b. i = Imax sin(120πt - 60)

c. i = Imax sin(120πt + 30)

d. i = Imax sin(120πt - 30)

94. What is the power factor (pf) of a series RL circuit having R=50 ohms and XL=20

ohms?

a. 0.63

b. 0.71

c. 0.81

d. 0.93

95. 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 decrease

96. A 6-ohms resistor is connected in series with a capacitive reactance of 8 ohms. 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

97. The apparent power of a series RC network is given to be 4000 W. If R=6 ohms

and XC=8 ohms, calculate the true power of the network.

a. 1200 W

b. 2400 W

c. 3200 W

d. 4000 W

98. A series RC circuit has an apparent power of 4000 W. If R=6 ohms and XC=8

ohms, determine the reactive power.

a. 1200 W

b. 2400 W

c. 3200 W

d. 4500 W

99. What is the total impedance of a series circuit consisting of R=6 ohms, XC=8

ohms and XL=16 ohms?

a. 10 ohms

b. 14 ohms

c. 24.73 ohms

d. 30 ohms

100. 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

101. The name of pure semiconductor material that has equal number of

electrons and holes

a. n-type

b. pure type

c. intrinsic

d. p-type

102. 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

103. Germanium has an atomic number of 32 and 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

104. The atomic weight of a silicon atom is approximately 28 amu. How may

electrons, protons and neutrons does the atom consist?

a. 14,42,14

b. 14,14,42

c. 42,14,14

d. 14,14,14

105. A semiconductor that is free from impurities

a. intrinsic semiconductor

b. extrinsic semiconductor

c. compensated semiconductor

d. elemental semiconductor

106. Example of acceptor impurities

a. pentavalent impurities

b. trivalent impurities

c. tetravalent impurities

d. hexavalent impurities

107. Commonly used as donor impurities

a. Antimony (Sb)

b. Arsenic (As)

c. Phosphorus (P)

d. All of the above

108. 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

109. Semiconductor whose electron and hole concentrations are equal

a. extrinsic semiconductor

b. intrinsic semiconductor

c. compensated semiconductor

d. doped semiconductor

110. 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

111. The electrical resistance of a semiconductor material will _______ as the

temperature increases

a. increase

b. increase exponentially

c. decrease

d. not change

112. 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 10^5 per cubic cm

b. 1.5 x 10^10 per cubic cm

c. 1.5 x 10^15 per cubic cm

d. 1.5 x 10^20 per cubic cm

113. What is the basis in operation of semiconductor photoconductors?

a. EHP generation

b. EHP degeneration

c. EHP optical degeneration

d. EHP optical generation

114. 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

115. 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

116. 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

117. 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

118. 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. dipping

d. clamping

119. 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

120. 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

121. 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

122. As the operating temperature of as reverse-biased diode is increase, its

leakage or reverse saturation current will

a. increase

b. increase exponentially

c. decrease

d. decrease exponentially

123. The breakdown voltage of 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

124. Calculate the new threshold voltage of a germanium diode when it

operates at 100ºC

a. 0.113 V

b. 0.188 V

c. 0.215 V

d. 0.513 V

125. A silicon diode has a reverse saturation current of 50 nA at room

temperature. If the operating temperature is raised by 50ºC, what is now the

reverse saturation current?

a. 105.56 nA

b. 287.73 nA

c. 827.89 nA

d. 1.66 µA

126. 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

127. 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

128. 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

129. A certain diode has a maximum power dissipation of 500 mW at room

temperature and a linear derating factor of 5.0 mW/ºC. How much power the

diode can handle if operated at 50ºC?

a. 625 mW

b. 505 mW

c. 495 mW

d. 375 mW

130. A semiconductor device especially fabricated to utilize the avalanche or

zener breakdown region. This is normally operated in the reverse-region and its

application mostly for voltage reference or regulation.

a. varactor diode

b. zener diode

c. shockley diode

d. schottky barrier diode

131. 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

132. 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

133. Another name of a three-layer diode. This is also considered as an ac

diode

a. shockley diode

b. thyrector

c. thyristor

d. diac

134. When the p-n junction of a semiconductor diode is inserted with intrinsic

material, the diode becomes a

a. backward diode

b. read diode

c. shockley diode

d. PiN diode

135. A diode that is especially processed so that its high-current flow takes

place when the junction is reversed-biased. It is a variation of a tunnel diode.

a. esaki diode

b. read diode

c. zener diode

d. backward diode

136. 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

137. The appearance of RF current oscillations in a dc-biased slab of n-type

gallium arsenide in a 3.3kV electric field

a. Gunn effect

b. Hall effect

c. Zener effect

d. Avalanche

138. Quiescent or Q-point is dependent on

a. the supply voltage

b. the load resistance

c. the type of diode

d. All of the above

139. A germanium diode is connected to a load resistance of 1.5 kilo ohms 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]

140. What is the drop across the diode when it is connected in series to a

resistor of 1.8 kilo ohms 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’t be solved, lack of data

141. Two germanium diodes are connected in series and have a load resistance

of 10 kilo ohms 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

142. A silicon diode is in parallel with a germanium diode and is connected to a

load resistor having a value of 20 kilo ohms 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

143. 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 solved, lack of data

144. 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

145. A chopper, employing an alternately biased diode as the switching

element

a. diode chopper

b. active chopper

c. junction chopper

d. All are correct

146. 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 ohms

b. 250 ohms

c. 25 kilo ohms

d. 250 kilo ohms

147. The flow of electron in a NPN transistor when used in electronic circuit is

from

a. collector to base

b. base to collector

c. emitter to collector

d. base to emitter

148. 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 electronic.

a. triode

b. triac

c. SCR

d. transistor

149. 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

150. At forward-biased junction of PNP transistor, majority carriers flow

heavily

a. from p- to the n-type material

b. from n- to p-type material

c. from p- to p-type material

d. A and B above

151. Phrases “not pointing in” and “pointing in” simply means

a. npn and pnp

b. pnp and npn

c. npn only

d. pnp only

152. The formal name of βəc

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

153. 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

154. 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

155. 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

156. If the base-emitter junction is reversed biased and the base-collector

junction is forward biased, the transistor will be at what region of operation?

a. active region

b. cutoff region

c. saturation region

d. breakdown region

157. What region the transistor should be operating to have minimum distortion

at the output signal?

a. active region

b. cutoff region

c. saturation region

d. None of the above

158. Solve for the base current if the collector current is 600 mA and the

current gain is 20.

a. 30 mA

b. 3 mA

c. 12 mA

d. 1.2 mA

159. A transistor with β=100 is connected as common base; was found to have

a leakage current ICBQ=1 µA. 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

160. 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. cutoff frequency

d. unity gain bandwidth product or unity current gain bandwidth

product

161. When the base is common to both the input and output sides of the

configuration and is usually the terminal closest to, or at ground potential, it is

called what?

a. common-emitter terminology

b. common-collector terminology

c. common-base terminology

d. All of these

162. Which of the transistor configuration has the highest input resistance?

a. common base

b. common emitter

c. common collector

d. common transistor

163. 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

164. Most frequently used transistor configuration for pnp and npn

a. common-base

b. common-collector

c. common-emitter

d. A and C above

165. 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

166. Considered as the basic FET or the simplest form of FET

a. JFET

b. MOS-FET

c. IGFET

d. VMOS-FET

167. 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

168. 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

169. For a normal operation of an n-channel JFET, d\how do you bias the gate-

source junction?

a. positive-negative respectively

b. negative-positive respectively

c. forward-biased

d. Any of the above

170. The current that flows into channel of a JFET when the gate-source

voltage is zero

a. drain-source saturation current

b. drain-source cutoff current

c. drain-source leakage current

d. drain-source pinch-off current

171. 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

172. 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

173. 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

174. 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

175. 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

176. 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

177. 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

178. The base material of a MOSFET which extends as an additional terminal

a. source (S)

b. channel (C)

c. drain (D)

d. substrate (SS)

179. 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/V^2

a. 1.2 mS

b. 2.4 mS

c. 3.6 mS

d. 7.2 mS

180. Which FET operates as close as BJT in terms of switching?

a. JFET

b. MOSFET depletion type

c. MOSFET enhancement type

d. IGFET

181. 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

182. 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

183. 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

184. If a transistor amplifier provides a 360º output signal, it is classified as

a. Class A

b. Class B

c. Class C

d. Class D

185. An amplifier that delivers an output signal of 180º only

a. Class A

b. Class B

c. Class AB

d. Class D

186. A full 360º sine-wave signal is applied as an input to an unknown class of

amplifier, if the output delivers only a pulse of less than 180º, of what class does

this amplifier belongs?

a. Class AB

b. Class B

c. Class C

d. Class D

187. 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%

188. Transistorized class C power amplifiers will usually have an efficiency of

a. 25%

b. 33%

c. 50%

d. 78.5%

189. 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%

190. An amplifier of class AB means its output signal is between the output of

class B and A, such that it varies from 180º (class B) to 360º (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%

191. 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

192. Which amplifiers can be used for linear amplification?

a. Class A

b. Class B

c. Class C

d. Class A or B

193. 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

194. 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

195. 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

196. 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

197. The overall gain of an amplifier in cascade is

a. the sum

b. the average of each

c. the product

d. 100% the sum

198. A direct-coupled two-stage transistor configuration wherein the outputn of

the first 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

199. Famous transistor amplifier configuration designed to eliminate the so

called Miller effect

a. cascode amplifier

b. darlington amplifier

c. differential amplifier

d. complementary-symmetry

200. 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

201. An amplifier having high-direct current stability and high immunity to

oscillation, this is actually 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

202. One of the most versatile and widely used electronic device in linear

applications

a. SCR

b. FET

c. UJT

d. Op-amp

203. It is very high-gain differential amplifier with very high input impedance

and very low output impedance

a. par-amp

b. op-amp

c. differential amplifier

d. complementary amplifier

204. 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

205. An operational amplifier must have at least how many usable terminals?

a. 3 terminals

b. 5 terminals

c. 8 terminals

d. 14 terminals

206. The circuit at the input stage of operational amplifiers

a. differential amplifier

b. cascaded amplifier

c. current mirror

d. complementary amplifier

207. An amplifier whose output is proportional to the difference between the

voltages applied to its two inputs

a. differential amplifier

b. differencing

c. delta amplifier

d. cascode-amp

208. 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

209. How does the input of an op-amp make 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

210. 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

211. 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

212. Primarily, op-amps are operated with bipolar power supply, however, we

can also use single polarity 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

213. 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 180º, 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 to 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

214. 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

215. 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

216. 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

217. 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

218. 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

219. The µA741 op-amp has a CMRR of 90 dB 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

220. 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

221. 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

222. 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

223. 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

224. 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 kilo ohms and a feedback resistance of 100 kilo ohms

a. 0.1 mV

b. 1.0 mV

c. 10.0 mV

d. 100.0 mV

225. An op-amp inverting amplifier uses a feedback resistor of 100 kilo ohms

and input resistor of 10 kilo ohms. 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

226. 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

227. What is the 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

228. 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

229. 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

230. 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

231. The reduction of op-amps gain due to increasing operating frequency

a. Cutoff

b. Roll-off

c. Diminishing factor

d. Reduction step

232. 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

233. 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

234. 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

235. 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%

236. 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

237. 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

238. The feedback element of a differentiator constructed from op-amp is

a. a resistor

b. an inductor

c. a capacitor

d. an RC network

239. The voltage gain of an op-amp voltage follower

a. Unity

b. Rf/Ri

c. 1 + Rf/Ri

d. Depends on the type of an op-amp

240. A unity-gain summing amplifier has three input, 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

241. 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

242. Approximate the noise-gain of an inverting adder using op-amps if its has

five inputs

a. Unity (1)

b. Two (2)

c. Four (4)

d. Six(6)

243. 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

244. 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

245. 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

246. 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

247. 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

248. Dual-in-line or DIL package is designated as

a. TO-99

b. TO-91

c. TO-116

d. TO-220

249. For high density ICs involving many op-amps, what packaging is suitable?

a. Metal can

b. 14-pin DIL

c. SMT

d. Flat-pack

250. Example(s) of surface-mounted technology (SMT) devices

a. PLCCs

b. SOICs

c. LCCCs

d. All of the above

251. Circuits that produces alternating or pulsating current or voltage

a. Damper

b. Generator

c. Oscillator

d. Mixer

252. What do you call the oscillator circuit that uses a tapped coil in the tuned

circuit?

a. Pierce

b. Colpitts

c. Hartley

d. Ultraudion

253. Type of oscillator whose frequency is dependent on the charge and

discharge of the RC networks

a. Hartley oscillator

b. Colpitts oscillator

c. Relaxation oscillator

d. Klystron oscillator

254. A microwave oscillator

a. Hartley oscillator

b. Colpitts oscillator

c. Relaxation oscillator

d. Klystron oscillator

255. A self-excited oscillator in which the tank is divided into input and

feedback potions by a capacitive voltage divider

a. Hartley oscillator

b. Colpitts oscillator

c. Relaxation oscillator

d. Klystron oscillator

256. 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

257. A multivibrator that generates one output pulse for each input trigger pulse

a. monostable

b. astable

c. bistable

d. tristable

258. Monostable multivibrator is also known as

a. one shot

b. single shot

c. direct shot

d. one shot or single shot

259. A multivibrator having two stable states

a. monostable

b. bistable

c. astable

d. unstable

260. It is also known as Eccles/Jordan circuit

a. monostable multivibrator

b. bistable multivibrator

c. astable multivibrator

d. unstable multivibrator

261. Flip-flop is actually a _______ multivibrator

a. monostable

b. bistable

c. astable

d. unstable

262. Considered as a free-running multivibrator

a. monostable

b. bistable

c. astable

d. unstable

263. 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=1.2 V

a. Leclanche cell

b. Dry cell

c. Edison cell

d. Lead-acid cell

264. 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

265. 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

266. How long will a battery need to operate a 240 Watts equipment, whose

capacity is 100 Ah and 24 volts rating?

a. 5 hrs

b. 10 hrs

c. 1 hr

d. 0.10 hr

267. 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

268. 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

269. The flat 9-V battery has how many cells in series?

a. 3

b. 4

c. 6

d. 9

270. 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

271. Electricity that is generated due to heat, as in thermocouple

a. Thermodynamics

b. Thermojunction

c. Electric heater

d. Thermoelectricity

272. Electrical machines refer to machines that convert

a. mechanical to electrical energy

b. electrical to mechanical energy

c. electrical energy to one form of electrical energy of another form

d. all of the above

273. Electrical machine that converts ac voltage to dc voltage or vice versa

a. generator

b. motor

c. rotary converter

d. frequency converter

274. 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

275. 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

276. 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

277. 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

278. 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

279. What should be the speed of a 6-pole ac generator in order to have a

frequency of 50 Hz?

a. 100 rpm

b. 500 rpm

c. 1000 rpm

d. 1500 rpm

280. 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

281. In dc motors, when does severe arcing happen?

a. During starting

b. During rated speed

c. During speed fluctuation

d. During shutdown

282. 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

283. 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

284. 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

285. 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

286. Which thyristor is commonly used as motor speed control?

a. Triac

b. Diac

c. SCR

d. SUS

287. 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

288. 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

289. 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

290. Generally, in what application you consider the use of one-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

291. _________ currents are wasteful currents which flows in cores of

transformers and produces heat

a. Residual

b. Eddy

c. Sneak

d. Magnetizing

292. 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

293. The ratio of the amount of the 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

294. 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 the 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

295. 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

296. The dc-voltage of a full wav bridge rectifier

a. 0.318 Vmax

b. 0.45 Vmax

c. 0.636 Vmax

d. 0.90 Vmax

297. 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

298. Which power supply filter gives the smallest ripple voltage?

a. Capacitor filter

b. RC-filter

c. LC-filter

d. Multi-section LC-filter

299. A voltage regulator connected in parallel with the load

a. Series regulator

b. Parallel regulator

c. Shunt regulator

d. Switching regulator

300. 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

301. Three-terminal fixed positive voltage regulators commonly used in

industry

a. 78XX series

b. 79XX series

c. 723 IC regulator

d. 317 regulator

302. The three-terminal voltage regulator 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

303. 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

304. 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

305. 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

306. One of the major concerns in power electronics is to clean-up or shape-up

the utility-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

307. 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

308. 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

309. Precision is also known as

a. Correctness

b. Accuracy

c. Sharpness

d. Reproducibility

310. Errors due 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

311. 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

312. 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

313. A permanent-magnet moving-coil instrument

a. Induction instrument

b. D’ Arsonval meter movement

c. Moving-iron instrument

d. Moving-magnet instrument

314. 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 an 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

315. Measurement of high dc-voltages is usually done by using

a. electrostatic

b. dynamometer

c. thermocouple

d. PMMC

316. The 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

317. Resistance measuring instrument particularly used in determining the

insulation resistance

a. Megaohmmeter

b. Megger

c. Galvanometer

d. A and B are correct

318. 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

319. Which dynamometer instrument has a uniform scale?

a. Voltmeter

b. Ammeter

c. Ohmmeter

d. Wattmeter

320. Error in ammeter reading is due to

a. Insertion

b. Loading

c. Battery aging

d. Conversion

321. For the greatest accuracy, what should be the input impedance of a VOM?

a. 1,000 ohms/V

b. 50,000 ohms/V

c. As large as possible

d. As small as possible

322. A meter has a full-scale current of 50 µA, what is its sensitivity?

a. 20 kilo ohms/V

b. 20 V/ohm

c. 50 kilo ohms/V

d. 50 µA/V

323. If a meter with full-scale current of 100 µA is used as an ac voltmeter with

a half-wave rectification, its ac sensitivity is

a. 10,000 ohms/V

b. 4,500 ohms/V

c. 9,000 ohms/V

d. 100 ohms/V

324. The zero-adjust control in an analog type ohmmeter 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

325. 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

326. 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 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

327. 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

328. This is a method of using a Wheatstone bridge to determine the distance

from the test point to a fault in telephone or telegraph line or cable

a. Mesh

b. Varley loop

c. Batten system

d. Cordonnier system

329. 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

330. 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

331. When the capacitors of a Wein bridge are replaced by inductors, the

bridge becomes

a. Wein-bridge filters

b. Variometer

c. Schering bridge

d. Wein inductance bridge

332. 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

333. 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

334. 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

335. When the meter is insufficiently damped, it is considered as

a. Underdamped

b. Overdamped

c. Critically damped

d. Negatively damped

336. A meter when _____ damped will become insensitive to small signals

a. Under

b. Over

c. Critically

d. Negatively

337. One type of circuit control device which may be manual, automatic or

multi-contact

a. Fuse

b. Breaker

c. Switch

d. Relay

338. 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

339. An electronic switch that has the highest single-device current capacity

and can withstands overloads better

a. Thyratrons

b. Ignitrons

c. SCR

d. Triac

340. A semiconductor, electronic switch that has the highest single-device

current rating

a. Thyristor

b. Triac

c. SCR

d. Quadrac

341. 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

342. 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

343. 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

344. The most popular thyristor used in electrical power controllers

a. SCR

b. Triac

c. SCS

d. PUT

345. What is true about SCRs after they are being switched “ON”?

a. The anode to cathode continues to conduct even if the gate triggering

voltage is removed

b. The gate 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

346. 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 must be positive with respect to the cathode

d. All of the above

347. A SCR rated 10 A is used as the controlling switch in a circuit powered by

50 Vdc. When the SCR fires ON, its anode to cathode voltage was observed to be

2 V. calculate the break-back voltage of the SCR

a. 25 Vdc

b. 32 Vdc

c. 41 Vdc

d. 48 Vdc

348. 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

349. 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

350. 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 gat-to-cathode resistor

c. By shunting a capacitor across the anode and cathode of each SCR

d. By using a blocking-equalizing resistor

351. 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 increase the leakage current towards the load

d. All of the above

352. 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

353. 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-trigger transformer

c. By using reactors

d. All of the above are possible

354. 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)

355. 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

356. Which are the three terminals of a TRIAC?

a. Gate, anode1 and anode2

b. Gate, source and sink

c. Base, emitter and collector

d. Emitter, base 1 and base 2

357. A silicon bilateral switch may be considered as a small power triac and

has three terminals namely

a. Anode 1, anode 2 and gate

b. Main terminal 1, main terminal 2 and gate

c. Anode, cathode and gate

d. Both A and B are acceptable

358. Silicon unilateral switches (SUSs) generally have a break-over 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 and cathode 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

359. Thyristor whose characteristic curve closely resembles that of SCR’s and

SUS’s except that its forward break-over voltage (+VBO) is not alterable, for the

device has no gate terminal

a. Diac

b. Thyrector

c. UJT

d. Shockley diode

360. A UJT or unijunction transistor is a three terminal break-over 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

361. A UJT has an internal resistances of RB1=6 kilo ohms and RB2=3 kilo

ohms, what is its interbase resistance?

a. 2 kilo ohms

b. 3 kilo ohms

c. 6 kilo ohms

d. 9 kilo ohms

362. Why does thyristors with high break-back voltage desirable?

a. It dissipates less power

b. It generates less heat

c. It is more efficient

d. All of the above

363. After the squeeze interval, what comes next in an automatic welding

system?

a. Squeeze interval

b. Weld interval

c. Hold interval

d. Standby interval

364. During 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

365. Industrial circuit or system that is not self-correcting

a. Open-loop

b. Closed-loop

c. System with feed back

d. Non-servo

366. In control system, closed-loop means

a. It has feedback

b. It is self-correcting

c. It is self-regulating

d. All are correct

367. In closed-loop control 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

368. 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

369. The small error signal or system deviation where the system cannot

correct anymore

a. Threshold

b. Holding

c. Offset

d. Bias

370. _______ 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

371. 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

372. A programmable, multifunction manipulator designed to move materials,

parts, tools or specific devices

a. Industrial robot

b. Android

c. Actuator

d. End effector

373. The technology for automations

a. Avionics

b. Cryogenics

c. Cryotronics

d. Robotics

374. 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

375. Actuators used in industrial robots

a. Electric motors

b. Fluid motors

c. Fluid cylinders

d. All of these are correct

376. Which of the actuators that has the greatest force capability?

a. Electric

b. Hydraulic fluid

c. Pneumatic

d. Magnetic

377. Actuator that requires the highest initial cost

a. Electric

b. Hydraulic fluid

c. Pneumatic

d. Magnetic

378. Robot actuator that has the highest operating cost

a. Electric

b. Hydraulic fluid

c. Pneumatic

d. Magnetic

379. The most messy robot actuator

a. Electric

b. Hydraulic fluid

c. Pneumatic

d. Magnetic

380. 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

381. 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

382. 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

383. 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

384. 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

385. SCARA robots have how many axis of motion?

a. 2

b. 4

c. 6

d. 8

386. SCARA robots are designed for what applications?

a. Machining

b. Welding

c. Assembling

d. Handling heavy tools

387. 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

388. 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%

389. Usually used to drive low-speed alternators

a. Diesel engines

b. Jet propulsion engines

c. Steam turbines

d. Hydraulic turbines

390. Usually used to drive high-speed alternators

a. Diesel engines

b. Pneumatic engines

c. Steam turbines

d. Hydraulic turbines

391. 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

392. For what reasons, 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

393. Alternators have less chance to hunt if driven by

a. Steam turbines

b. Hydroturbines

c. Diesel turbines

d. Nuclear reactor

394. In alternators, what is the purpose of the damper winding?

a. It prevents over speeding

b. It maintains constant speed

c. It prevents hunting

d. It protects overloading

395. 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

396. In paralleling ac generators, _______ is very important

a. Voltage level

b. Current level

c. Phase angle

d. Internal resistance

397. Description used for generators trying to self-adjust its parameters before

paralleling with on line generators

a. Synchronizing

b. Sequencing

c. Jogging

d. Aligning

398. 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

399. How are alternators rated?

a. In Watts

b. In kW

c. In kVar

d. In kVA

400. In electrical power distributions, what insulator is generally used?

a. Rubber

b. Wood

c. Plastic

d. Porcelain