Electronics Engineering Mastery Test 19: ECE Pre-Board Practice Exam

This is the Electronics Engineering Mastery Test 19 in Electronics Engineering ECE Board Examination taken from various sources including but not limited to past Board Exam Questions in Electronics Engineering Licensure Examination, Electronics Books, Journals and other Electronics References. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in Electronics Engineering within 5 hours. You have to get at least 70% to pass the subject. Electronics Engineering is 30% of the total 100% Board Rating along with Mathematics (20%), General Engineering and Applied Sciences (20%) and Electronics Systems and Technology (30%).

Topic Outline included in Electronics Engineering Syllabi

• MCQ in DC Electrical Circuits
• MCQ in AC Electrical Circuits
• MCQ in Electromagnetics
• MCQ in Electronic Devices and Circuits
• MCQ in Electronic Circuit Analysis and Design
• MCQ in Electronic Systems and Design
• MCQ in Logic Circuits and Switching Theory
• MCQ in Microprocessor and Microcontroller Systems and Design
• MCQ in Feedback and Control Systems

Start the Test Yourself Exam 19

⇐ Electronics Engineering Mastery Test 18: ECE Pre-Board

Choose the letter of the best answer in each questions.

1. If bandwidth increases, the

a. center frequency decreases

b. Q decreases

c. Roll-off rate increases

d. 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 these

3. Which of the following robot drive mechanism is the cheapest to buy but has a limited payload?

a. thermionic

b. hydraulic

c. pneumatic

d. electric

4. The output of an OR gate will be low if

a. all inputs are HIGH

b. all inputs are LOW

c. 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 be

a. smooth dc at a constant voltage

b. pure ac with equal peak voltages

c. ac with one peak voltage greater than the other

d. fluctuating dc

6. In constructing transformers, the primary and secondary windings should have

a. good electrical coupling

b. loose magnetic coupling

c. tight magnetic coupling

d. best inductive coupling

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 V

c. 100 V

d. half of its maximum voltage

8. What is the typical slew rate of Fairchild 741 op-amp?

a. 1 V/μs

b. 10 V/μs

c. 0.5 V/μs

d. 0.333 V/μs

9. Small microcomputer used as a dedicated controller for a machine, a piece of equipment, or a process.

a. Microcomputer

b. Microprocessor

c. Microcontroller

d. Supercomputer

10. Where do you classify cobalt as material?

a. Non-magnetic

b. Ferromagnetic

c. Paramagnetic

d. Diamagnetic

11. If the base-emitter junction is open, the collector voltage is

a. V_cc

b. 0 V

c. floating

d. 0.2 V

12. The absolute maximum rating for op-amps interval power dissipation is

a. 500mW

b. 300mW

c. 200mW

d. 100mW

13. The power dissipated in the core due to hysteresis and eddy current losses

a. iron loss

b. copper loss

c. winding loss

d. friction loss

14. Which of the following is not an internal digital IC fault?

a. open signal lines

b. shorted signal lines

c. faulty power supply

d. poor solder connections

15. A diode limiter circuit

a is useful for voltage regulation

b. always uses zener diodes

c. rectifies the audio to reduce distortion

d. 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 dense

b. Flux lines are not present

c. Flux lines are not being cut

d. 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 ohms

c. 14 ohms

d. 6 ohms

18. A radio equipment will be used to 70% at 50 amperes rating of 5 hours, how much capacity of dry battery is needed?

a. 35

b. 17.5

c. 250

d. 175

19. Type of feedback employed in oscillators

a. negative

b. zero

c. positive

d. inductive

20. A digital circuit that oscillates between two unstable output states.

a. monostable multivibator

b. astable multivibrator

c. bistable multivibrator

d. flip-flop

21. Capacitors are used to store data in

a. timers

b. op amps

c. multiplexers

d. none of these

22. The input resistance of a common-base amplifier is

a. very low

b. very high

c. 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=1

c. 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 voltage

c. input offset voltage

d. Ground voltage

25. Type of waveform generated by the sweep generator of the CRT.

a. sine wave

b. spike

c. square wave

d. sawtooth

26. What are the primary methods of controlling electrical power?

a. by using manual switches and rheostats

b. by using variable reactance and transformers

c. by using electronic  switches, such as diodes, transistors, thyratrons, and thyristors

d. all of these

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

a. PAL

b. PLA

c. PLD

d. PROM

28. Flux linkage equals

a. flux times area of the core

b. flux times the number of turns times area of the core

c. flux times number of turns times length of the core

d. 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 diode

c. Varistor

d. Back Diode

30. How many NAND-gates are required to form an OR-gate?

a. 2

b. 3

c. 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 gain

c. 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 technique

c. 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 have

a. Z_o = 188 Ω

b. Z_o = 150 Ω

c. Z_o = 225 Ω

d. Z_o = 375 Ω

34. How many cells would a 16 word x 6 bit memory contain?

a. 16

b. 96

c. 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 kHz

c. 18.52 kHz

d. 54 kHz

36. The purpose of the I layer in a PIN diode is to

a. minimize the diode capacitance

b. optimize the avalanche voltage

c. reduce the forward breakover voltage

d. 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. precision

c. 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. motor

c. PLC

d. servo

40. A JFET always operates with

a. the gate-to-source pn junction reverse-biased

b. the gate-to-source pn junction forward-biased

c. the drain connected to the ground

d. the gate connected to the source

41. If I_c is 50 times greater than I_B, then β_DC is

a. 0.02

b. 100

c. 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 Hz

c. 90 Hz

d. 120 Hz

43. Which of the following amplifiers is considered linear?

a. class A

b. class B

c. 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 360°  sine wave signal is applied to an unknown class of amplifier. If the output delivers only a pulse of less than 180° , what class does this amplifier belongs?

a. class AB

b. class B

c. 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 cycle

b. the polarity reverses periodically

c. the electrons always flow in the same direction

d. there is a definite frequency

47. A summing amplifier can have

a. No more than two input signals

b. Two or more input signals

c. A closed-loop input impedance of infinity

d. A small open-loop voltage gain

48. In an NPN circuit, the collector

a. has an arrow pointing inward

b. is positive with respect to the emitter

c. is biased at a small fraction of the base bias

d. 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 than

c. less than

d. either A or B

50. A device used to mechanically measure the output power of a motor.

a. dynamometer

b. Megger

c. concentric-vane instrument

d. Radial vane instrument

51. How many major lobes are produced by a paraboloid reflector?

a. one

b. two

c. three

d. four

52. The main problem with a bar-graph meter is that:

a. it isn’t very sensitive

b. it isn’t stable

c. it can’t give a very precise reading

d. 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 flux

b. air works at higher frequencies than ferromagnetic

c. ferromagnetic are lossy than air

d. 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 increase

b. increase power consumption

c. maximum voltage swing will increase

d. large variation in the input offset voltage

56. If a power supplies 30 V with no load and 20 V 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 circuit

c. Clapp circuit

d. Armstrong circuit

58. A pulsating dc applied to power amplifiers causes

a. burning of transistor

b. hum in the circuit

c. excessive forward voltage

d. excessive reverse voltage

59. In a linear op-amp circuit, the

a. Signals are always sine waves

b. Op-amp does not go into saturation

c. Input impedance is ideally infinite

d. 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 0

c. latch

d. don’t care

61. The regulator with the highest efficiency is the

a. shunt regulator

b. series regulator

c. 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 system

c. servo system

d. differential system

63. An integrated circuit for both astable and monostable applications.

a. 741 op-amp

b. discrete ICs

c.  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 complement

c. 9’s complement

d. 10’s complement

65. Low sensitive DC voltmeter provides inaccurate result when measuring ____ circuits.

a. zero resistance

b. high resistance

c. at any resistance

d. low resistance

66. Simple current limiting produces too much heat in

a. Zener diode

b. Load resistor

c. Pass transistor

d. Ambient air

67. When an armature opens in dc motor, it may cause

a. intermittent sparking

b. an increase in speed

c. the motor to slow down

d. the motor to stop rotating

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 parallel

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

c. a 3×3 series-parallel matrix of resistors

d. 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 that

a. the toroid is easier to wind

b. the solenoid cannot carry as much current

c. the toroid is easier to tune

d. the magnetic flux in a toroid is practically all within the core

70. The input offset current is usually

a. less than the input bias current

b. equal to zero

c. less than the input offset voltage

d. 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 SCR

c. compound generator

d. universal motor

72. The ideal internal resistance of an emitter should be

a. equal to the circuit resistance

b. zero

c. infinity

d. higher than circuit resistance

73. A frequency synthesizer has

a. high power output

b. high frequency drift rate

c. exceptional stability

d. an adjustable wave shape

74. The approximation with a maximally flat passband is

a. Chebyshev

b. Inverse chebyshev

c. Elliptic

d. Bessel

75. Electron flow assumes charges flow from

a. negative to positive

b. negative to negative

c. positive to negative

d. positive to ground

76. The closed-loop voltage gain of an inverting amplifier equals

a. The ratio of the input resistance to the feedback resistance

b. The open-loop voltage gain

c. The feedback resistance divided by the input impedance

d. The input resistance

77. A bubble memory is best suited for:

a. a large computer

b. a home video entertainment system

c. a portable cassette player

d. a magnetic disk

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

a. 1/(2π√LC)

b. 1/(2πRC)

c. 1/(4πLC)

d. 1/(29RC)

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 times

c. 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. generator

c. 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 amplifiers

c.  level detector

d. integrator

82. Which of the following is not a characteristic of CMOS chips?

a. sensitivity to damage by electrostatic discharge

b. low current demand

c. ability to work at high speed

d. 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 set

c. 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. pivotal

c. 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 direction

b. high current

c. very low current

d. high voltage

87. The energy of an oscillator can be sourced by

a. coupling a small coil close to the tube

b. capacitance of inductive coupling from the tuned circuit

c. Inserting resistor in grid circuit

d. connecting capacitor across the supply

88. Air works well as a dielectric mainly because it

a. has a high dielectric constant

b. is not physically dense

c. has low loss

d. allows for large capacitance in a small volume

89. An AC bridge that measures inductance in terms of resistance and capacitance.

a. Owen’s bridge

b. Murray loop

c. Schering bridge

d. Kelvin bridge

90. A monopulse receiver has how many separate channels?

a. one

b. two

c. 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 conducting

a. a small part of the time

b. all of the time

c. only when the input voltage exceeds a limit

d. only when there is an overload

93. Each stage of a four-stage amplifier has a voltage gain of 15. The overall voltage gain is

a. 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 density

c. multiplexing

d. corruptibility

95. What is the purpose of the emitter capacitor?

a. to forward bias the emitter

b. to reduce noise in the amplifier

c. to avoid drop in gain

d. 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 provide

a. A short duration pulse

b. A long duration pulse

c. a digitally compatible output

d. All of these

98. One of the following items below is not one of the main components of an alternating current power supply.

a. power transformer

b. Filter

c. Voltage regulator

d. Rectifier

99. What are the two basic categories of industrial robots?

a. autobots and deceptions

b. mechanical and electrical

c. fast and slow

d. 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 flow

b. in all direction, omnidirectional

c. in the same direction of the current

d. in a direction determined by the left hand rule

Complete List of Electronics Engineering Pre-Board Exams