ECE Board Exam:April 2005:Electronics

1. The main purpose of an instrumentation amplifier is _____.a. To compare input signals.b. To amplify small signals that are riding on large common mode voltages.c. To reject unwanted signals.d. To trim small signals that are riding on large common mode voltages.

2. In a series RLC circuit, what is the condition of the circuit if there is high impedance, low current, and low reactance voltages?

a. Ideal circuitb. Percent circuitc. Resonantd. Non-resonant

3. The most accurate type of test equipment used for measuring high power is the _____.

a. Bolometerb. Wavemeterc. Calorimeterd. Wattmeter

4. The effect on the human body of 21-20 mill-amperes, 60 Hz A.C. or 80-?? milli-amperes D.C is ______.

a. Respiratory failureb. Mascular inhibitionc. Reflex actiond. Surprise

5. A straight line plot of collector current Ic and Vce for a transistor circuit is called the _____.

a. Threshold lineb. DC loadlinec. Loading limitd. Linear level

6. If a transformer has a turns ratio of 1:3, what is the current ratio?a. 1:3b. 1:9c. 3:1d. 9:1

7. There is a _____ degrees of inversion between gate and drain voltages of an FET.a. Zerob. 90c. 180

d. 270

8. A differential circuit uses a _____.a. Capacitor in its feedback circuitb. RLC in its feedback circuitc. Inductor in its feedback circuitd. Resistor in its feedback circuit.

9. Which of the following shells contain 2 electrons?a. Lb. Nc. Md. K

10. What amplifier is used when power from a convertion servoamplifier is too small to drive large servomotors (either A.C or D.C.)?

a. Differential amplifierb. RD amplifierc. Audio amplifierd. Operational amplifier

11. An amplifier which is designed to be used with other circuit component to perform either computing functions or some type of transfer operation?

a. Differential amplifierb. RD Amplifierc. Audio amplifierd. Operational amplifier

12. What type of LC oscillator is sometimes called a “tickler” oscillator in reference to the transformer secondary or tickler coil that provides the feedback to keep the oscillator going?

a. Colpittsb. Clappc. Armstrongd. Hartley

13. The ratio of the DC collector current Ic to the emitter current Ie is called the DC ______.

a. Deltab. Beta (Bdc)c. Echod. Alpha (Adc)

14. The effect of 60 Hz A.C. over 100 mA or DC over 300 mA on the human body.a. Mascular inhibitionb. Respiratory failure

c. Surprised. Usually fatal

15. The bit storage capacity of a Read Only Memory(ROM) with a 512 x 8 organization is _____ bits.

a. 1024b. 8192c. 4096d. 2048

16. The device used to produce a gradual chance of impedance at the end of a waveguide is called a _____.

a. Funnelb. Loadc. Dummyd. Horn

17. In a robots, he axis that allows rotation are often referred to as _____ jointsa. Revolvingb. Revolutec. Resoluted. Rotary

18. The most widely used combination bias system in basic transistor amplifiera. Limited typeb. Current divider typec. Voltage-divider typed. Base current type

19. The open-loop gain of an op-amp is given at 225,000. Find the gain in dB.a. 1070b. 107c. 214d. 10.7

20. A _____ is a solid material formed by atoms bonding together in a fixed pattern.a. Block b. Crystalc. Latticed. Pyramid

21. Elements with 5 or more valence electrons are called _____.a. Semi-conductorsb. Conductorsc. Moleculed. Insulators

22. When the resistance of the load is high with respect to the resistance of the source _____ in a circuit is achieved.

a. Maximum powerb. High efficiencyc. Maximum transferd. High voltage

23. As the input voltage varies within specified limits, the zener diode maintains a nearly constant output voltage across its terminal. This is called _____.

a. Auto regulationb. Specific regulationc. Line regulationd. Load regulation

24. The method of assigning more sectors to the outer disk tracks is referred to as _____ recording.

a. Randomb. Zonec. Sectord. System

25. _____ is the unit of electrical current flow.a. Voltb. Ohmc. Amepered. Watt

26. According to Ohm’s Law, what happens to the circuit current if the circuit resistance increases?

a. Current doubleb. Current decreasesc. Current increasesd. Current remains constant

27. Determine the open loop gain of an Op-am whose cur-off frequency is 100 Hz with a midrange voltage gain of 100,000.

a. 7,071b. 707.1c. 70,710d. 70.71

28. DC biasing is used to establish a steady level of transistor current. This is called the _____.

a. Operating coordinatesb. Threshold point

c. Range of operationd. DC operating point

29. Arc blow can be avoided in electrical welding by _____a. Increasing arc lengthb. Welding away from the earth ground connectionc. Using bare electrodesd. Using AC welding machines

30. The distance covered or traveled by a waveform during the time interval of one complete cycle.

a. Frequencyb. Wavelengthc. Time slotd. Wave time

31. _____ is the non-linear distortion characterized by the appearance (at the system output)_ of frequencies equal to the sums or difference of two or more frequencies at the input.

a. Differential distortionb. Inter modulation distortionc. Mutual distortiond. Modulated distortion

32. Find the phase angle between the voltage across and the current through the circuit when Xc is 25 ohms, R 100 ohms and Xl is 50 ohms.

a. 76 degrees with the voltage leading the currentb. 14 degrees with the voltage lagging the currentc. 14 degrees with the voltage leading the currentd. 76 degrees with the voltage lagging the current

33. If the resistance of a circuit is doubled and the applied voltage is kept constant, the current will _____.

a. Be quadrupledb. Remain the samec. Be cut in halfd. Be doubled

34. To produce tin film resistors, which of the following materials is the most widely used?

a. Titaniumb. Tantalumc. Nichromed. Chromium cermets

35. Which of the following are techniques used to eliminate bonding wire and to improve packaging in IC production?

a. Flip chipsb. Beam lead chipsc. Flat packd. DIP

i. A,B, and C onlyii. A and C only

iii. A and B onlyiv. A,B,C, and D

36. List the two advantages of a voltage divider in DC biasinga. Unstable, uses two supply voltagesb. Unstable, uses one supply voltagec. Stable, uses one supply voltagesd. Stable, uses two supply voltages

37. _____ is a kind of oscilloscope which consist of narrowband if filter and a local oscillator (receiver) capable of showing transmitter carriers, spacing, harmonics and sidebands.

a. Polygraphb. Harmonics analyzerc. Spectrum analyzerd. Computerized tomography

38. One cycle is equal to how many degrees of rotation of a conductor in a magnetic field?

a. 270b. 360c. 180d. 90

39. A measuring device which will result to full scale reading at shorted terminal condition

a. Voltmeterb. Ammeterc. Electrostatic meterd. Ohmmeter

40. which of the following are the buses for information transfer internally and externally in a microprocessor

a. address busb. data busc. control bus

i. A and C onlyii. A and B only

iii. B and C onlyiv. A, B, and C only

41. If the voltage gain for each input of a summing amplifier with a 4.8 kilo-ohm feedback resistor is unity, the input resistors must have a value of _____ kilo-ohm.

a. 4.8 times the number of inputsb. 48c. 4.8 divided by the number of inputsd. 4.8

42. To match the waveguide to the load, _____ devices are placed in the waveguide.a. Standing waveb. Resistivec. Metal plated. Impedance changing

43. What is the generic term for utilities and programs needed to operate a computer system?

a. Hardwareb. Softwarec. People waterd. Tupper ware

44. The computer worm that infected computer systems world-wide in 10 minutes, making it the fastest computer virus ever known is called _____.

a. Claw Hammerb. Sledge Hammerc. SQL Hammerd. SARS Virus

45. The channel of JFET is between the _____.a. Input and outputb. Drain and sourcec. Gate and draind. Gate and source

46. What is the common use of a push-pull amplifier?a. AN OPAMb. A driverc. Wideband amplifierd. A coupler

47. For a bipolar junction transition(eto tlga yung nakalagay) (BJT) to operate properly, the base-collector junction should be _____ biased.

a. Positiveb. Forwardc. Negatived. Reverse

48. Large centralized data-processing complexes like multi-national companies, departments and corporations use which type of general-purpose computer that operates programs simultaneously?

a. Mini-computerb. Micro0computerc. Main-frame computerd. Super-computer

49. In parallel resonant LC circuit, what is the impedance at resonant frequency?a. Zerob. The maximum impedance valuec. Infinityd. Determined solely by the dc resistance

50. The area in which the axis motion of a robot manipulator can operate without any obstruction is called the e_____.

a. Work areab. Range of operationc. Range of motiond. Work envelope

51. The BEST choice electronic device to turn a device at a particular voltage is a/an _____.

a. SCR b. SCSc. DIACd. PUT

52. What term is used to describe the ability a system to distinguish between targets that are close together?

a. Radar sensitivityb. Target designationc. Radar agilityd. target resolution

53. What do you call a concept which describes the relationship of all functional components of a computer such as CPU and input./output devices?

a. Engineering developmentb. Architecturec. Prototypingd. Pre-production modeling

54. The use of feedback to achieve the desired response of a dynamic system in the presence of uncertainties, disturbance or constraints is called _____.

a. Synchronization

b. Responsec. Controld. Servomechanism

55. The primary purpose of a voltage regulator is to provide an output voltage with little or no _____.

a. Figure of meritb. Valuec. Regulationd. Variation

56. Displays files in specified directory and all subdirectoriesa. Solidb. Dopedc. Intrinsicd. Extrinsic

57. In waveguide theory, what causes the current-carrying area at the center conductor of the coaxial line to be restricted to a small layer at the surface?

a. Dielectric lossesb. Standing wavec. Skin effectd. Copper losses

58. This peak current specified for a given number of cycles or portion of a cycle.a. Surge currentb. Maximum currentc. Peak surge currentd. High current

59. An electron moves into the electrostatic field between a positive charge and a negative charge. Toward which charge will the electron move?

a. Outwardsb. The negative chargec. The centerd. The positive charge

60. _____ is the definite discrete amount of energy required to move an electron from a lower shell to a higher shell

a. Quantumb. Positive energyc. The centerd. The positive charge

61. Which of the following are the basic measurements?a. Voltage

b. Currentc. Resistanced. Capacitance and conductance

i. Neither (a and b) nor (c, d, and e)ii. A, b, c, d , and e

iii. C, d, and e onlyiv. A and b only

62. Monolithic integrated circuits are usually referred to as _____.a. Selenium rectifiersb. ?? (ndi ko na mabasa)c. Silicon chipsd. Hybrids

63. _____ is an intermodulation condition that occurs when a carrier modulates by an undesired signal.

a. Short modulationb. Cross modulationc. Under modulationd. Over modulation

64. In microwave tubes, what is the basic principle of operations of a klystron?a. Strong electrostatic fieldb. Energy transfer and amplificationc. Oscillationd. Velocity modulation

65. An English scientist who drew up plans for the first programmable computer in 1830

a. Vannevar bushb. William oughtredc. Charles Babbaged. Herman hollerith

66. In an optical coupler, this parameter is the ratio of the output current to the input current through the LED, expressed in percentage. What is this ratio?

a. DC current coupling ratiob. AC current transfer ratioc. AC current coupling ratiod. DC current transfer ratio

67. _____ refers to the difference between the carrier frequencies of an FM signal and the instantaneous frequency of its modulated wave.

a. Differential frequencyb. Frequency deviationc. Modulated frequency

d. Frequency band

68. The most widely used abrasive is _____.a. Tungstenb. Graphitec. Silicon carbided. Alumina

69. The most common bias circuit providing Q-point stability with a single polarity supply voltage is what type bias circuit

a. Collector feedbackb. Voltage dividerc. Emitterd. Base

70. What happens to the portion of the wave front that do not satisfy the boundary conditions, when a wavefront is radiated into a waveguide?

a. It collapsesb. It decreases to zeroc. It is reflected backd. It increases to maximum

71. The schokeydiode(eto tlga yungnakalagay. Schokey diode) is a thyristor that conducts when the voltage across its terminal exceed the _____ potential.

a. Triggerb. Breakoverc. Operatingd. Maximum

72. The value of the drain-to-source voltage of a GFET at which the drain current becomes constant when the gate-to-source voltage is zero is called _____ voltage.

a. Breakdownb. Cut offc. Thresholdd. Pinch off

73. Insulators are characterized by a _____ energy gap between its conduction bands an valence band.

a. Very narrowb. Widec. Very wided. Narrow

74. _____ is an electrical current that flows in one direction only.a. Normal currentb. Alternating current

c. Direct currentd. Eddy current

75. The input resistance at the gate of an FET is _____.a. Relatively lowb. Zeroc. Extremely highd. Average

76. It is the generated in a D.C. motor as armature coils out the field flux opposes the applied voltage, and limits the flow of armature current.

a. Electromotive forceb. Field excitationc. Counter-electromotive forced. Armature excitation

77. The person responsible for the researend(as is) design and development of a complete information system.

a. PROGRAMMERb. PEOPLE WAREc. SYSTEM ANALYSTd. COMPUTER OPERATOR

78. In a robotic system, how many degrees of freedom can be given to a manipulator by adding a wrist?

a. Fourb. Sixc. Threed. Two

79. Term for energy that is stored in electromagnetic or electrostatic field.a. Amperes-joulesb. Joules-coulombsc. Potential energyd. Kinetic energy

80. What do you call the “Filter” between a corporate network and the internet that keeps the corporate network secure from intruders while giving corporate users unhibited access to the internet?

a. Bandstep (as is)b. Bandpassc. Firewalld. Firestorm

81. Which of the following circuit conditions requires circuit protection?a. Direct short/shot circuit

b. Excessive heatc. Excessive current

i. A and C onlyii. A, B and C only

iii. B and C onlyiv. A and B only

82. Two basic categories of voltage regulators area. Differential, integralb. Capacitive, inductivec. Linear switchingd. Centrifugal, centripetal

83. A measure of the energy absorbed from radiation by tissue or other biological material and is a equal to the transfer of 1 x 10-2 Joules energy per kilogram of material is called a _____.

a. Radicalb. Radc. Radiand. Radius

84. The type of feedback used to increase amplitude of output signal.a. Negative feedbackb. Unwanted feedbackc. Positive feedbackd. Fidelity feedback

85. A transistor constructed with three-doped semiconductor region separated by two pn junction is called a _____.

a. Metal oxide semiconductor FETb. Field effect transistorc. Junction field effect transistord. Bipolar junction transistor

86. A type of filter that passes a narrow band of frequencies though a current and attenuates the desired band of frequencies that are high or lower than the desired band of frequencies.

a. Low-pass filterb. Band-reject filterc. Band-pass filterd. High-pass filter

87. Which of the following are circuit control devices?a. Switchesb. Solenoidc. Relays

i. B and C onlyii. A and B only

iii. A, B, and Civ. A and C only

88. What is an electric measuring equipment used in navigation which uses time measurement concept for a wave to travel from a place receiving station and back?

a. Tacanb. OODRc. ILSd. DME

89. In a stand alone supply of power the rationale of cells making in series is to _____.a. Increase current capacityb. Increase voltage outputc. Decrease voltage outputd. Decrease internal resistance

90. _____ is the total number of magnetic lines of force in a magnetic field.a. Magnetic potentialb. Magnetic fluxc. Magnet flux intensityd. Flux density

91. An electronic device that can be turned on and turned off by a gate pulse is called a _____.

a. Bipolar junction transistorb. Silicon-controlled switchc. Silicon-controlledrectiriferd. Shockley diode

92. Which of the following are categories of computer system software?a. Operating system (OS)b. Utility programsc. Languages translator

i. A and B onlyii. B and C only

iii. A and C onlyiv. A, B, and C

93. A hot-carrier diode is a diode that ____.a. Emits light when forward biasedb. Switches very fastc. Varies resistance with temperatured. Changes its capacitance with voltage

94. Which of the following are UJT terminals?a. Emitterb. Basec. Base2d. Gate

i. B, C and D onlyii. A, B, and C only

iii. A, B and D onlyiv. All of the above

95. An amplifier exhibits three critical frequencies in its low-frequency responsea. None of theseb. 167hertzc. 130 hertzd. 75 hertz

96. The value of anode current below which the SCR switches from the forward-conduction region to the forward blocking region is called _____ current.

a. Switching, Isb. Operation, Ioc. Holding, Ihd. Forward blocking, Ibl (f)

97. In a transformer, the principle of electromagnetic induction is also known as _____.a. Coupling actionb. Transformationc. Matching actiond. Transformer action

98. The symbols 1, 2 and 3 through 9 are what type of numerals?a. Booleanb. Romanc. Binaryd. Arabic

99. Type of semiconductor diode varies its internal capacitance as the voltage applied to its terminals varies.

a. A zener diodeb. A varactor diodec. A silicon-controlled rectifierd. A tunnel diode

100. Which of the following are means of achieving tin films in IC manufacturing?a. Thermal growthb. Chemical vapor depositionc. Evaporation

i. A and C onlyii. B and C only

iii. A, B, and C iv. A and B only

Answer key: (yung iba wla talagang sagot..)

1. B2. D3. C4. B5. B6. C7. C8. D9. D10. B11. D12. C13. D14. D15. C16. D17. A18. C19. B20. B21. D22. D23. C24. C25. C26. B27. C28. D29. D30. B31. B32. C33. C34. C35. C36. C37. C38. B39. D

40. D41. D42. D43. B44. C45. B46. B47. D48. C49. B50. D51. C52. D53. B54. C55. D56. ?57. C58. C59. D60. A61. D62. C63. B64. D65. C66. A67. B68. D69. B70. B71. B72. D73. C74. C75. C76. C77. A78. C

79. C80. C81. B82. C83. B84. C85. D86. C87. C88. B89. B90. B91. B92. A93. B94. B95. D96. ?97. D98. D99. B100. ?