Republic of the PhilippinesEDGE ECE REVIEW SPECIALIST

BOARD OF ELECTRONICS ENGINEERINGELECTRONICS ENGINEER LICENSURE EXAMINATION

ELECTRONICS ENGINEERING

INSTRUCTION: Do not write anything on this questionnaire. Select the correct answer for each of the following questions. Mark only one answer for each for each item by shading the box corresponding to the letter of your choice on the answer sheet provided.

1. If bandwidth increases, thea. center frequency decreasesb. Q decreasesc. Roll-off rate increasesd. Ripples appear in the stopband

2. The dc output of a bridge type circuit is ____ that of equivalent center-tapped circuit.a. the same as b. more than c. less than d. none of the above

3. Which of the following robot drive mechanism is the cheapest to buy but has a limited payload?a. thermionic b. hydraulicc. pneumatic d. electric

4. The output of an OR gate will be low ifa. all inputs are HIGH b. all inputs are LOWc. one input is LOW d. Undetermined

5. If a 175-V dc source were connected in series with the utility mains from a standard wall outlet, the result would bea. smooth dc at a constant voltageb. pure ac with equal peak voltagesc. ac with one peak voltage greater than the otherd. fluctuating dc

6. In constructing transformers, the primary and secondary windings should havea. good electrical coupling b. loose magnetic couplingc. tight magnetic coupling d. best inductive coupling

7. If a sine wave voltage varies from 0-200 V, how much is its instant voltage at 90 degrees?a. minimum voltage b. 200 Vc. 100 V d. half of its maximum voltage

8. What is the typical slew rate of Fairchild 741 op-amp?a. 1 V/us b. 10 V/usc. 0.5 V/us d. 0.333 V/us

9. Small microcomputer used as a dedicated controller for a machine, a piece of equipment, or a process.a. Microcomputer b. Microprocessorc. Microcontroller d. Supercomputer

10. Where do you classify cobalt as material?a. Non-magnetic b. Ferromagneticc. Paramagnetic d. Diamagnetic

11. If the base-emitter junction is open, the collector voltage isa. Vcc b. 0 Vc. floating d. 0.2 V

12. The absolute maximum rating for op-amps interval power dissipation isa. 500mW b. 300mWc. 200mW d. 100mW

13. The power dissipated in the core due to hysteresis and eddy current lossesa. iron loss b. copper lossc. winding loss d. friction loss

14. Which of the following is not an internal digital IC fault?a. open signal lines b. shorted signal linesc. faulty power supply d. poor solder connections

15. A diode limiter circuit a is useful for voltage regulation

b. always uses zener diodesc. rectifies the audio to reduce distortiond. can cause objectionable signal distortion

16. An elementary generator consists of a single coil rotating in a magnetic field. Why is no voltage induced in the coil as it passes through the neutral plane?a. Flux lines are too denseb. Flux lines are not presentc. Flux lines are not being cutd. Flux lines are being cut in the wrong direction

17. A manufacturer quotes in his specifications that a silicon diode conducts 50 mA at 1 V. Determines its bulk resistance.a. 20 ohms b. 4 ohmsc. 14 ohms d. 6 ohms

18. A radio equipment will be used to 70% at 50 amperes rating fo 5 hours, how much capacity of dry battery is needed?a. 35 b. 17.5c. 250 d. 175

19. Type of feedback employed in oscillatorsa. negative b. zeroc. positive d. inductive

20. A digital circuit that oscillates between two unstable output states.a. monostable multivibator b. astable multivibratorc. bistable multivibrator d. flip-flop

21. Capacitors are used to store data ina. timers b. op ampsc. multiplexers d. none of the above

22. The input resistance of a common-base amplifier isa. very low b. very highc. the same as CE d. the same as CC

23. What is the normal resting state of the SET and CLEAR inputs in a NAND gate latch?a. SET=1, CLEAR=1 b. SET=0, CLEAR=1c. SET=1, CLEAR=0 d. SET=0, CLEAR=0

24. Voltage that is present at the output of an operational amplifier with its two inputs grounded.a. common-mode signal b. output offset voltagec. input offset voltage d. Ground voltage

25. Type of waveform generated by the sweep generator of the CRT.a. sine wave b. spikec. square wave d. sawtooth

26. What are the primary methods of controlling electrical power?a. by using manual switches and rheostatsb. by using variable reactance and transformersc. by using electronic switches, such as diodes, transistors,

thyratrons, and thyristorsd. all of the above

27. Class of programmable logic devices wherein its AND array is programmable while its OR array is hard wired.

a. PAL b. PLAc. PLD d. PROM

28. Flux linkage equalsa. flux times area of the coreb. flux times the number of turns times area of the corec. flux times number of turns times length of the cored. flux times number of turns

29. The device used to use for rectifying a weak ac signal is a a. Zener diode b. Light-emitting diodec. Varistor d. Back Diode

30. How many NAND-gates are required to form an OR-gate?a. 2 b. 3c. 4 d. 5

31. What gain is significant when an op-amp is used as a voltage comparator?a. open-loop gain b. common voltage gainc. differential closed loop gain d. closed loop gain

32. Process of repairing the ruptured crystal structure caused by ion implantation by heating.a. photolithography b. Czochralski techniquec. diffusion d. annealing

33. Suppose a purely resistive impedance of 75 Ω must be matched to a purely resistive impedance of 300 Ω. A quarter-wave section would need to havea. Zo=188 Ω b. Zo=150 Ωc. Zo=225 Ω d. Zo=375 Ω

34. How many cells would a 16 word x 6 bit memory contain?a. 16 b. 96c. 22 d. 108

35. Find the half-power bandwidth of a parallel resonant circuit which has a resonant frequency of 8.1 MHz and Q of 150.a. 21.1 kHz b. 47.3 kHzc. 18.52 kHz d. 54 kHz

36. The purpose of the I layer in a PIN diode is toa. minimize the diode capacitanceb. optimize the avalanche voltagec. reduce the forward breakover voltaged. increase the current through the diode

37. The typical saturation flux density for most magnetic materials.a. 0.1 Wb/m2 b. 2 Wb/m2

c. 10 Wb/m2 d. 20 Wb/m2

38. _____ is a measure of consistency of measurements.a. standards b. precisionc. accuracy d. exactness

39. A digital computer used for the automation of industrial processes, such as control of machinery or factory assembly lines.a. microcontroller b. motorc. PLC d. servo

40. A JFET always operates witha. the gate-to-source pn junction reverse-biasedb. the gate-to-source pn junction forward-biasedc. the drain connected to the groundd. the gate connected to the source

41. If Ic is 50 times greater than IB, then βDC isa. 0.02 b. 100c. 50 d. 500

42. What is the ripple frequency of a half-wave rectifier with an input line frequency of 60 Hz?a. 30 Hz b. 60 Hzc. 90 Hz d. 120 Hz

43. Which of the following amplifiers is considered linear?a. class A b. class Bc. class C d. either class A or B

44. Electrical classification of materials having 8 electrons.a. insulator b. semiconductor

c. conductor d. compound

45. A full 360o sine wave signal is applied to an unknown class of amplifier. If the output delivers only a pulse of less than 180 o , what class does this amplifier belongs?a. class AB b. class Bc. class C d. class D

46. Which of the following is not a general characteristic of an ac wave?a. the wave shape is identical for each cycleb. the polarity reverses periodicallyc. the electrons always flow in the same directiond. there is a definite frequency

47. A summing amplifier can havea. No more than two input signalsb. Two or more input signalsc. A closed-loop input impedance of infinityd. A small open-loop voltage gain

48. In an NPN circuit, the collectora. has an arrow pointing inwardb. is positive with respect to the emitterc. is biased at a small fraction of the base biasd. is negative with respect to the emitter

49. The bandwidth of a multistage amplifier is ___ that of a single stage amplifier.a. the same as b. more thanc. less than d. either A or B

50. A device used to mechanically measure the output power of a motor.a. dynamometerb. Meggerc. concentric-vane instrumentd. Radial vane instrument

51. How many major lobes are produced by a paraboloid reflector?a. one b. twoc. three d. four

52. The main problem with a bar-graph meter is that:a. it isn’t very sensitiveb. it isn’t stablec. it can’t give a very precise readingd. you need a special training to read it

53. What is the maximum efficiency of a full-wave center-tapped rectifier?a. 50% b. 40.6%c. 81.2% d. 10%

54. Which of the following is false, concerning air cores versus ferromagnetic cores?a. air concentrates the magnetic lines of fluxb. air works at higher frequencies than ferromagneticsc. ferromagnetics are lossy than aird. a ferromagnetic core unit needs fewer turns of wire than an

equivalent air core unit

55. Which statement is wrong regarding μA741 when its supply voltage is increased?a. open-loop voltage gain will increaseb. increase power consumptionc. maximum voltage swing will increased. large variation in the input offset voltage

56. If a power supplies 30 V with no load and 20V under full load, what is the percentage regulation?a. 33% b. 66.67%c. 75% d. 50%

57. Which type of the following oscillator types uses transformer coupling to feed back a portion of the signal voltage. It is sometimes called a “tickler” coil.a. Hartley circuit b. Colpitts circuitc. Clapp circuit d. Armstrong circuit

58. A pulsating dc applied to power amplifiers causesa. burning of transistor b. hum in the circuit

c. excessive forward voltage d. excessive reverse voltage

59. In a linear op-amp circuit, thea. Signals are always sine wavesb. Op-amp does not go into saturationc. Input impedance is ideally infinited. Gain-bandwidth product is constant

60. Situation when a circuit’s output level for a given set of input conditions can be assigned as either a 1 or 0.a. logic 1 b. logic 0c. latch d. don’t care

61. The regulator with the highest efficiency is thea. shunt regulator b. series regulatorc. switching regulator d. Dc-to-dc converter

62. When a closed-loop system is used to maintain physical position it is referred to as a. gyro system b. feedback systemc. servo system d. differential system

63. An integrated circuit for both astable and monostable applications. a. 741 op-amp b. discrete ICsc. Monolithic ICs d. 555 timer

64. Result obtained when a 1 is added to the least significant bit position of a binary number in the 1’s-complement form.a. 1’s complement b. 2’s complementc. 9’s complement d. 10’s complement

65. Low sensitive DC voltmeter provides inaccurate result when measuring ____ circuits.a. zero resistance b. high resistancec. at any resistance d. low resistance

66. Simple current limiting produces too much heat in a. Zener diode b. Load resistorc. Pass transistor d. Ambient air

67. When an armature opens in dc motor, it may causea. intermittent sparking b. an increase in speedc. the motor to slow down d. the motor to stop rotating

68.Suppose you have an unlimited supply of 1-W, 1000-Ω resistors, and you need a 500-Ω resistance rated at 7 W or more. This can be done by assembling a. four sets of two resistors in series, and connecting these

four sets in parallelb. four sets of two resistors in parallel, and connecting these four

sets in seriesc. a 3x3 series-parallel matrix of resistorsd. a series-parallel matrix, but something different than those

described above.

69. A significant advantage, in some situations, of a toroidal coil over a solenoid is the fact thata. the toroid is easier to windb. the solenoid cannot carry as much currentc. the toroid is easier to tuned. the magnetic flux in a toroid is practically all within the

core

70. The input offset current is usuallya. less than the input bias currentb. equal to zeroc. less than the input offset voltaged. unimportant when a base resistor is used

71. Combination of ac motor, dc generator, and exciter to provide adjustable voltage dc power to a dc motor.a. ward-leonard system b. half-wave SCRc. compound generator d. universal motor

72. The ideal internal resistance of an emitter should bea. equal to the circuit resistanceb. zeroc. infinityd. higher than circuit resistance

73. A frequency synthesizer hasa. high power output b. high frequency drift ratec. exceptional stability d. an adjustable wave shape

74. The approximation with a maximally flat passband isa. Chebyshev b. Inverse chebyshevc. Elliptic d. Bessel

75. Electron flow assumes charges flow froma. negative to positive b. negative to negativec. positive to negative d. positive to ground

76. The closed-loop voltage gain of an inverting amplifier equalsa. The ratio of the input resistance to the feedback resistanceb. The open-loop voltage gainc. The feedback resistance divided by the input impedanced. The input resistance

77. A bubble memory is best suited for:a. a large computerb. a home video entertainment systemc. a portable cassette playerd. a magnetic disk

78. The operating frequency of a Wien-bridge oscillator is given by ___.

a. b.

c. d.

79. In an LC oscillator, if the value of L is increased four times, then frequency of oscillations is ____.a. decreased two times b. increased two timesc. decreased four times d. increased four times

80. This type of electrical machine is used for varying the input voltage into a higher or lower potential without changing the power transferred.a. motor b. generatorc. transformer d. alternator

81. Amplifier of low-level signals that provides an output that is an accurate multiple of the difference between two input signals.a. Schmitt trigger b. instrumentation amplifiersc. level detector d. integrator

82. Which of the following is not a characteristic of CMOS chips?a. sensitivity to damage by electrostatic dischargeb. low current demandc. ability to work at high speedd. ability to handle extremely high power

83. How are the networks able to transform one impedance to another?a. The matching network introduces transconductance to cancel

the resistive part of impedance.b. Resistance in the networks substitute for the resistances

in the load.c. The matching network introduces negative resistance to

cancel the resistive part of an impedance. d. The matching network can cancel the reactive part of an

impedance and change the value of the resistive part of an impedance.

84. Power source that converts desired electricity to the other.a. motor set b. motor-generator setc. voltage regulator d. power regulator

85. It is a robot structure wherein the body can pivot vertically and horizontally and that arms move radially.a. polar structure b. pivotalc. cylindrical structure d. roborat

86. How do you determine if diode is effective?a. diode resistance is either very high or very low in either

directionb. high current c. very low currentd. high voltage

87. The energy of an oscillator can be sourced bya. coupling a small coil close to the tube b. capacitance of inductive coupling from the tuned circuitc. Inserting resistor in grid circuitd. connecting capacitor across the supply

88. Air works well as a dielectric mainly because ita. has a high dielectric constantb. is not physically dense c. has low lossd. allows for large capacitance in a small volume

d. 4.92 GHZ

89. An AC bridge that measures inductance in terms of resistance and capacitance.a. Owen’s bridge b. Murray loopc. Schering bridge d. Kelvin bridge

90. A monopulse receiver has how many separate channels?a. one b. twoc. three d. four

91. A meter when ___ damped will become insensitive to small signals.

a. underdamped b. overdamped c. critically damped d. negatively damped

92. In a linear regulator, the control transistor is conductinga. a small part of the time

b. all of the timec. only when the input voltage exceeds a limitd. only when there is an overload

93. Each stage of a four-stage amplifier has a voltage gain of 15. The overall voltage gain isa. 60 b. 15 c. 50,625 d. 3078

94. With respect to memory, which of the following terms means that the data contents vanish if power is removed from a chip?a. volatility b. component densityc. multiplexing d. corruptibility

95. What is the purpose of the emitter capacitor?a. to forward bias the emitterb. to reduce noise in the amplifier c. to avoid drop in gaind. to stabilize emitter voltage

96. The number of digits used by a number system. a. digits b. radix c. 2n d. n

97. A Schmitt trigger is used to providea. A short duration pulseb. A long duration pulse c. a digitally compatible output

d. All of the above

98. One of the following items below is not one of the main components of an alternating current power supply.a. power transformer b. Filterc. Voltage regulator d. Rectifier

99. What are the two basic categories of industrial robots?a. autobots and deceptionsb. mechanical and electrical c. fast and slowd. pick and place manipulator and intelligent robot

100. What direction is the magnetic field about a conductor when current is flowing?a. in a direction opposite to the current flowb. in all direction, omnidirectionalc. in the same direction of the currentd. in a direction determined by the left hand rule

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