Electronics Engineering Mastery Test 14: ECE Pre-Board

This is 100 items set of Practice Examination 14 in Electronics Engineering composed of previous and/or potential Board Exams Questions. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in Electronics Engineering within 4 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%).

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⇐ Electronics Engineering Mastery Test 13: ECE Pre-Board

Choose the letter of the best answer in each questions.

1.  Refers to a form of dc motor-generator with common field coil for both motor and generator.

a.  motor-generator

b.  dyna-motor

c.  polyphase-motor

d.  synchronous-motor

2.  The condition under which there is no power loss due to reflection at a source/load junction owing to the fact that the load impedance is matched to the source

impedance.

a.  alignment

b.  resonance

c.  half-power point

d.  maximum power

3.  How do you call an eight element vacuum tube?

a.  pentode

b.  hexode

c.  octode

d.  septode

4.  Electric power refers to __________.

a.  joule

b.  watt second

c.  volt coulomb

d.  volt ampere

5.  __________ is the process of converting AC input to AC output to DC output.

a.  radiation

b.  attenuation

c.  rectification

d.  variation

6.  Clock periods are measured from_________.

a.  the high level to the low level

b.  the low level to the high level

c.  similar points on the clock waveform

d.  the clock pulse at 50% of its low or high levels

7.  Find the flux density in gauss having a flux of 20, 000 Mx through a perpendicular area of 2 cm squared.

a.  20, 000 G

b.  10, 000 G

c.  40, 000 G

d.  22, 000 G

8.  Process by which a magnetic substance becomes a magnet when it is placed near a magnet.

a.  electromagnetic induction

b.  magnetic reflection

c.  influx of density

d.  magnetic induction

9.  _______ is the physical motion resulting from the forces of magnetic fields.

a.  torque action

b.  repulsion

c.  motor action

d.  rotation

10. The purpose of the fetch cycle in a computer is to________.

a.  obtain instruction

b.  obtain input data

c.  obtain memory data

d.  implement a specific operation

11. The term used to describe the process whereby two transistors with positive feedback are used to simulate the action of the thyristor.

a.  arcing

b.  latching

c.  damping

d.  switching

12. ______ is a thin polished slice of a semiconductor crystal on which integrated circuit can be fabricated often in duplicate, for cutting into individual dice.

a.  silicon

b.  indium

c.  gallium

d.  wafer

13. _________ is a single bit comparator.

a.  wired OR

b.  exclusive OR

c.  NOR gate

d.  Exclusive NOR

14. The output pulses of the logic pulser __________.

a.  can damage logic circuits

b.  are too narrow for the logic probe to respond to

c.  can only force high nodes to low.

d.  can be used to over drive logic nodes high to low

15. _________ is the output of a half-wave rectifier.

a.  half-wave rectified signal

b.  square wave signal

c.  100% AC signal

d.  sinusoidal signal

16. An electronic semiconductor behaves as _______ at absolute zero temperature

a.  a variable resistor

b.  a conductor

c.  a super conductor

d.  an insulator

17. One advantage of hydraulic actuator type of an industrial robot is ____________.

a.  intrinsically safe in flammable environment such as painting

b.  clean-no-oil leaks

c.  lowest operating cost

d.  lowest initial cost

18. What conditions does resonance occurs in an electrical circuit?

a.  when the power factor is at minimum

b.  when the inductive and capacitive reactance are equal

c.  when the square root of the sum of the capacitive and inductive reactances is equal to the resonant  frequency

d.  when the square root of the product of the capacitive and inductive reactances is equal to the resonant frequency

19. A triac is a/an __________equivalent of two SCRs.

a.  series

b.  inverse-parallel

c.  parallel-series

d.  parallel

20. Radio equipment will be used 70% at 50 amperes rating for 5 hours, how much capacity of a dry battery is needed?

a.  35

b.  17.5

c.  250

d.  175

21. An insulating element or material has capability of________.

a.  conducting large current

b.  storing voltage

c.  storing high current

d.  preventing short circuit between two conducting wires

22. One of the following characteristics of a resistive material which do not change its resistive value with respect to time is its ______________.

a.  fidelity

b.  stability

c.  sensitivity

d.  selectivity

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

a.  pierce

b.  Colpitts

c.  Hartley

d.  Ultraudion

24. What do you call the flux does not follow the intended path in magnetic circuit?

a.  linked flux

b.  lost flux

c.  leakage flux

d.  leakage factor

25. Term for the phenomena which occurs in an electrical circuit when the inductive reactance balances with capacitive reactance.

a.  reactive equilibrium

b.  reactive quiescence

c.  high Q

d.  resonance

26. Type of diode that is made of metal whisker touching a very small semiconductor die.

a.  a junction diode

b.  varactor diode

c.  point contact diode

d.  zener diode

27. A_______ us a solid-state memory device which depends on the magnetic polarization of domains, usually in a garnet type material.

a.  magnetic disk

b.  magnetic core

c.  magnetic bubble

d.  magnetic drum

28. The anode of a semiconductor diode indicates a _____ charge during conduction.

a.  positive

b.  either depending on design

c.  neutral

d.  negative

29. Determine how long a battery will last whose rating is 100 Ah; 24 volts and will run a 300 watts electronic equipment and a 50 watts light.

a.  6.85 hours

b.  50.05 hours

c.  12.00 hours

d.  26.65 hours

30. What is the process used to describe analog-to-digital conversion?

a.  binarize

b.  linearize

c.  digitize

d.  analogize

31. Find the magnetomotive force of a circuit having 10 V across a relay, 50 turns of 2.5 ohms resistance.

a.  20 At

b.  200 At

c.  20, 000 At

d.  2000 At

32. Term used in electronic measuring devices when a metal increases resistance due to heat produced by current flowing through them.

a.  positive resistance coefficient

b.  negative resistance coefficient

c.  positive temperature coefficient

d.  negative temperature coefficient

33. How many symbols are used in octal digital number system?

a.  16

b.  4

c.  8

d.  2

34. Which of the following refers tot the point where the intensity of magnetic line of force is maximum?

a.  magnetic pole

b.  weak pole

c.  north pole

d.  great circle

35. How many silver zinc cells in series are needed for a 9 V battery?

a.  9

b.  6

c.  3

d.  7

36. How many does an ohmmeter behave if its positive lead is connected to the cathode of a diode while negative to anode?

a.  has infinite high resistance

b.  has unstable resistance

c.  has very low resistance

d.  has decreasing resistance

37. Where does practically all of the RF current flow in a conductor?

a.  along the surface

b.  in the center of the conductor

c.  in the electromagnetic field in the conductor center

d.  in the magnetic field around the conductor

38. What is a multi-wire connection between digital circuits?

a.  bus

b.  wire wrap

c.  multiplexed cable

d.  cable ribbon

39. Clock periods are measured from__________.

a.  similar points on the clock waveform

b.  from the time the clock pulses at 50% of its low-to-high transition until it is at 50% of its high-to-low  transition

c.  from the high level to the low level

d.  from the low level to the high level

40. ________refers to the majority carrier in an N-type semiconductor.

a.  hole

b.  positive ion

c.  negative ion

d.  electron

41. As you increase the doping level of a crystal diode its voltages_______.

a.  dextabilizes

b.  decreases

c.  increases

d.  stabilizes

42. Find the thevenins impedance equivalent across R2 of a linear close circuit having 10 V supply in series with the resistors (R1 = 100 ohms and R2 = 200 ohms).

a.  6.666 kohms

b.  66.6 ohms

c.  6.66 ohms

d.  666 ohms

43. A solid-state logical device which only gives a “1” output if all inputs are “0” is called a _____ gate.

a.  NOT

b.  NOR

c.  NAND

d.  OR

44. Which are the three terminals of a bipolar transistor?

a.  cathode plate and grid

b.  base, collector and emitter

c.  input, output and ground

d.  gate, source and sink

45. To cause a three-state buffer to output 0-1 levels, the following must be true:

a.  the output enable must be false

b.  the output enable must be true

c.  the info. Must have been stored in the buffet

d.  the signal OE must be at logic 1

46. ______is a software that converts a high level language program into machine or assembly language program.

a.  ALU

b.  Cross-assembler

c.  Compiler

d.  CPU

47.The relation of the voltage across an inductor to its current is describe as

a. leading the current by 90 degrees

b. lagging the current by 90 degrees

c. leading the current by 180 degrees

d. in phase with the current

48. Discrete optical waves than can propagate in optical waveguide are called __________.

a. modes

b. wavefront

c. nodes

d. step index

49. Reducing the plate and screen-grid voltages of an amplifier will________ control grid cut-off voltage.

a. unstable

b. increase

c. stay stable

d. decrease

50. An electrical temperature sensing device which is composed of a fair of different kinds of metal wires joined together in three complete loops.

a.  Thermocouple

b.  Photoconductive cell

c.  Psychrometer

d.  Flowmeter

51.  How much is the equivalent power in watts can a 3 horse power provide?

a.  248.66 watts

b.  1492 watts

c.. 2238 watts

d. 300 watts

52.  ____ is the term used to express the ratio of the change in dc collector current to a change in base current to a change in base current in a bipolar transistor.

a.  Alpha

b.  Delta

c.   Gamma

d.  Beta

53.  The rapidly flashing logic probe tip tells you that logic node being probe.

a.  has rapidly changing logic activity

b.  is truck

c.   is at an illegal logic level

d.  has unstable logic activity

54.  Which of the following is not used in hexadecimal digital symbols?

a.  A

b.  C

c.   H

d.  F

55.  Which  are the advantages of using an LED?

a.  Low power consumption and long life

b.  High lumens per cm per cm and low voltage requirements

c.   High lumens per cm per cm and low power consumption

d.  A current flows when the device is exposed to a light source

56.  A small metal cylinder which is a part of electron gun of the oscilloscope and has hole in one end.

a.  Aquadag

b.  Heater

c.  Grid

d.  Focus control

57. Find the power across the resistor of 5 ohms delivered from a battery of an internal resistance of an internal resistance of 3 ohms and a constant emf of 4 volts.

a. 100 watts

b. 60 watts

c. 120 watts

d. 1.25 watts

58. How many diodes will you use in designing a half-wave rectifier power supply?

a. Two

b. One

c. Four

d. Three

59. A haft-wave rectifier circuit utilizing one haft of an ac input cycle have a ripple frequency in its output equivalent to

a. 60 cps

b. 120 cps

c. 110 cps

d. 240 cps

60. _______ is a sequence of instruction that tell to the computer machine on how available data shall be processed.

a. Program

b. RAM

c. Command

d. Flowchart

61. A battery should not be charged or discharged at a high current in order to avoid this defect.

a. Corrosion

b. Sedimentation

c. Buckling

d. Sulphation

62. How does zener diodes widely used?

a. Current limiters

b. Variable resistors

c. Voltage regulators

d. Power collectors

63. Power source that converts desired electricity to the other.

a. Motor set

b. Motor-generator set

c. Voltage regulators

d. Power collectors

64. Rust in electrical (wire) connections will result to _______.

a. inductance

b. conductance

c. voltage

d. resistance

65. An oscillator which operates on the principle of velocity modulation and changing the speed of electron passing though the tube.

a. Magnetron

b. Hartley

c. Klystron

d. Colpitts

66. Identify from the following statement that does not refer to the use of signal generation when testing a receiver out of generating either modulated or unmodulated signal.

a. Testing of receiver performance

b. Receiver servicing

c. Receiver alignment

d. Display of voltage or current graphs

67. Which of the following refer to a characteristic of a magnetic line of force?

a. Travels from south to north through the surrounding medium of a bar magnet

b. Travels back and fourth between the north and south pole of a bar magnet

c. Travels from north to south through the surrounding of a bar magnet

d. Stay stationery between the north and the south of a bar magnet

68. A two-pole, three-phase motor has _______ fields poles.

a.   6

b.  8

c.  2

d.  4

69.  Where does the charge of standard electronic capacitor stored?

a.  air

b.  plates

c.  one of the terminals

d.  terminals

70. When power supply is constructed to operate from either 240V or 120V ac lines such that it will have same secondary output its primary when connected from 240V must be_______

a. completely no split

b. split exactly 1/ 3 from one end

c. split exactly 1/ 4 from one end

d. split exactly 1/ 2 from one end

71. How much power does electronic equipment consume, assuming a 5.50 amperes current and a 120 volt power source?

a. 66 watts

b. 60 watts

c.  125 .5 watts

d. 660 watts

72. ________ is the reciprocal of capacitance in electronics.

a.  Elastance

b. Permittivity

c.  Conductance

d.  Permeability

73. How does aquadag function?

a.  Limits incoming signals

b.  Collects electrons

c.  Measures waveforms

d.  Capture desired frequency

74. _______ are individual points in graphic display.

a.  Row

b.  Pixel

c.  Resolution

d.  Column

75. Which of the following equipment is used to determine location in terms of coordinate, this is now widely used in modern communications?

a.  Global positioning system

b.  Hydrometer

c.  Altimeter

d.  Bearing meter

76. How do you design direct current ammeter such that it could read high current values?

a.  Open the circuit

b.  Employ series resistors

c.  Employ series parallel resistors

d.  Employ shunt resistor across

77. Signal generators are classified according to frequency which are either a-f or r-f generators, a-f generators are referred to as

a. Hartley oscillators

b. Signal oscillators

c. Audio oscillators

d. Frequency oscillators

78. What does an integrated digital circuits generally made of?

a.  Hybrid

b. Plastic film

c  Monolithic

d. Thin film

79. Other factors remaining constant, what would be the effect on the current flow in a given circuit if the applied potential were doubled.

a.  It would double

b.  It would remain the same

c.  It would increase 4 times

d.  It would be reduced by 1/ 2

80 What is the equivalent of decimal 7 in octal?

a. 21

b. 49

c. 7

d. 14

81. Which one is the paramagnetic material?

a. Copper

b. Oxygen

c. Carbon

d. Bismuth

82. Dc generators develop ________ in its armature

a. direct current

b. inductance

c. heat

d. alternating current

83. The region in an electronic transistor that is very lightly doped and very thin is referred to the ______.

a. collector-base

b. collector

c. base

d. emitter

84. What is the function of flip-flop as logic element?

a. Stored binary data

b. Generates clock signal

c. Relay data

d. Makes decision

85. What is the property of the magnetic circuit that resist the establishment of flux?

a. Mutual inductance

b. Inductance

c. Reluctance

d. Permeance

86. Find the value of resistor with the following color codes, Brown, White, Orange, Red

a. 19 k ohms 2%

b. 190 ohms 10%

c. 19 k ohms 20%

d. 1.9 k ohms 5%

87. What is the term used to express the amount of electrical energy stored in an electrostatic field

a. Volts

b. Watts

c. Coulombs

d. Joules

88. What does the second strip of an electronic resistor color code represent?

a. Tolerance

b. Temperature

c. Second digit of the value

d. Multiplier

89. Which is not a part of cathode-ray tube oscilloscope?

a. Deflection plates

b. Electrons gun

c. Aquadag coating

d. Digital panel meter

90. An amplifier with an input resistance of 600 ohm has an input current of 500 microamperes. It delivers 100 mA to a 1000-ohm load. Calculate the dB gain of the amplifier.

a. 48.2 dB

b. 25.2 dB

c. 35.33 dB

d. 50.4 dB

91. What is a program that translate English-l like words of high level language into machine language of a computer?

a. Compiler

b. Assembler

c. Monitor program

d. Interpreter

92. Thyratrons in industrial electronics refers to _______

a. a gas-filled diode

b. a vacuum tube

c. gas-filled triode

d. an electronic triode

93. _______ is a table based on mathematical probabilities that can be used to calculate the number of circuits needed to a group in order to provide a specified grade of service of a given level of traffic.

a. Rayleigh distribution table

b. Probability traffic table

c. Busy hour table

d. Poisson table

94. Refers to the ratio of output voltage to the intensity of sound input of an audio instrument which is normally expressed in decibels.

a. Selectivity

b. Electrical ratio

c. Frequency response

d. Sensitivity

95. The decimal 36,020 is equivalent to hexadecimal _______.

a. 8CB4

b. 8SBC

c. 8BC8

d. 884C

96. How do you describe materials whose permeabilities are a little greater than that of free space?

a. Diamagnetic

b. Non- magnetic

c. Paramagnetic

d. Ferromagnetic

97. Why is the resistance of a conductor different for RF current than for DC?

a. Because of skin effect

b. Because conductors are nonlinear devices

c. Because the insulation conducts current at radio frequency

d. Because of the Heisenberg effect

98. Which network provide the greatest harmony suppression?

a. L – network

b. Pi – L – network

c. Pi – network

d. Inverse L – network

99. When you demagnetize properly by applying an AC field and then gradually reduced it to zero, it is called

a. damping

b. decaying

c. degaussing

d. gaussing

100. What is the equivalent of decimal 14 in binary?

a. 1110

b. 1011

c. 1101

d. 1111

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