# Electronics Engineering Mastery Test 9: ECE Pre-Board

(Last Updated On: April 4, 2021) This is 100 items of Practice Examinations set 9 in Electronics Engineering composed of previous 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%).

#### Start the Test Yourself Exam 9

Choose the letter of the best answer in each questions.

1. What is the maximum number of electrons in a subshell?

A. 2

B. 6

C. 10

D. 14

Solution:

2. The repeatability of a servo-controlled robot is within _____ mm rather than a fraction of a mm.

A. 2

B. 4

C. 3

D. 5

Solution:

3. What is the principal quantum number of a Q shell?

A. 6

B. 5

C. 4

D. 7

Solution:

4. What time when the voltage across L will be equal to the voltage across R in a series RL transient circuit where E = 24 V, R = 10 Ω and L = 1 H?

A. 69.3 ms

B. 69.3 s

C. 6.93 ms

D. 6.93 s

Solution:

5. What is the hysteresis loss at a frequency of 60 cycles per second of an audio transformer magnetic core which has a maximum flux density of 10,000 gausses? The volume of solid iron of this core is 66.8 cubic cm and the hysteresis coefficient (a constant that depends upon grade and quality of iron) id 5.35 x 10-4.

A. 0.5386 W

B. 53.86 W

C. 5.386 W

D. 5386 W

Solution:

6. When two coils of equal inductances are connected in series with coefficient of coupling and their fields in phase, find the total inductance of two coils.

A. 2LA

B. 2LA (1+k)

C. 2kLA

D. LA (2 + k)

Solution:

7. A 2 μF capacitor with initial charge q0 = 100 μC, is connected across a 100 Ω resistor at t = 0. Calculate the time in which the transient voltage across the resistor drops from 40 to 10 V.

A. 2.77 s

B. 0.277 ms

C. 2.77 ms

C. 0.277 s

Solution:

8. What do you call a small D.C generator built into alternators to provide excitation current to field windings?

A. prime mover

B. excitor

C. commutator

Solution:

9. What is the condition of the diode in a parallel-limiter when the output is developed?

A. Shunted

B. Conducting

C. Cut-off

D. Shorted

Solution:

10. What is the payload of the industrial robot AEA IRb-60?

A. 60 kg

B. 80 kg

C. 50 kg

D.70 kg

Solution:

11. Which of the following robot is primarily used for machining processes?

A. Cincinatti T1

B. Cincinatti T3

C. Cincinatti T2

D. Cincinatti T4

Solution:

12. The Kuka spot welding robot has how many degrees of freedom?

A. 4

B. 6

C. 5

D.7

Solution:

13. What system in industrial electronics has the ability to monitor certain variable in the industrial processes, the same can perform self-correcting action?

A. Coal-slurry system

B. Closed-loop system

C. Open-loop system

D. Feed forward control system

Solution:

14. What is the property of a gyro so that the axis of rotation or spin axis tends to remain in a fixed direction in space if no force is applied to it?

A. Selectivity

B. Precession

C. Rigidity

D. Sensitivity

Solution:

15. In a series RLC circuit with R= 200Ω L= 0.1 H and C= 5µF, find the transient current after the switch is closed at t=0 applying a 200V source.

A. 2e^(-1000t)sin 1000t

B. 2e^(-1000t)cos 1000t

C. 2e^(-100t)sin 100t

D. 2e^(-100t)cos 100t

Solution:

16. A 0.09 µF capacitor is charged to 220V. How long in milliseconds will it discharge to a level of 110V if the discharge resistor has a resistance of 20kΩ?

A. 1.25

B. 12.5

C. 125

D. 0.125

Solution:

17. What are the heavy particles that include the proton and the neutron?

A. Mesons

B. Baryons

C. Leptons

D. Quarks

Solution:

18. What particles have rest masses ranging down to about 0.1amu?

A. Leptons

B. Baryons

C. Quarks

D. Mesons

Solution:

19. By definition, what is the individual angular momentum of the neutron proton and electron?

A. h/4π

B. h/2π

C. h/π

D. 4πh

Solution:

20. In the hysteresis loop, what do you call the product of the residual magnetic flux and coercive field strength?

A. Effectivity product

B. Hysteresis coefficient

C. Residual-coercive product

D. Steinmetz’s product

Solution:

21. Programming of a continuous-path robot is normally carried out by a method called ______ through.

A. See

B. Walk

C. Pull

D. Push

Solution:

22. What do you call the strong magnetism that occurs in certain ceramic compounds such as ferrites?

A. Ferromagnetism

B. Ferrimagnetism

C. Diamagnetism

D. Paramagnetism

Solution:

23. What characteristic is determined by the time required for a voltage wave to travel from the input end of an electrical transmission line to the output end and back again?

A. Pulse position

B. Pulse line

C. Pulse width

D. Pulse code

Solution:

24. A disturbance similar to brownout but of shorter duration that occurs when the line voltage drops below 80-85% of its rated voltage by one or more cycles.

A. Sag or dip

B. Chronic overvoltage

C. Spike

D. Transient

Solution:

25. What term is given to the positions of the rotors of a synchro transmitter and the synchro receiver when both rotors are on a 0 degree displaced from 0 degree by the same angle?

A. Correspondence

B. Overlap

C. Fine tune

D. Stability

Solution:

26. What ac voltage defect refers to a high voltage (up to 6000V or more) peak lasting approximately 100µs to one-half cycle?

A. Sag or dip

B. Spike

C. Chronic overvoltage

D. Transient

Solution:

27. The largest computers commonly use a word size of ______ bits.

A. 32

B. 128

C. 64

D. 256

Solution:

28. What do you call the ratio of the safe load to the nameplate load of an electrical motor?

A. Service factor

C. Efficiency

D. Service life

Solution:

29. Covalent bond energy in germanium is about ____ eV.

A. 1.5

B. 7.4

C. 3.0

D. 4.7

Solution:

30. The service factors of motors vary from ____ to _____.

A. 2.5 to 2.9

B. 1.15 to 1.4

C. 1.1 to 1.3

D. 3.1 to 5.5

Solution:

31. How many voltage are available from two-phase, three wire alternator?

A. One

B. Three

C. Two

D. Four

Solution:

32. At what frequency does the RC circuit of an amplifier reduce the voltage gain to 70.7 percent of its midrange value?

A. Resonant

B. Cutoff

C. Critical

D. Natural

Solution:

33. What is the operating temperature of class A motor under motor classification?

A. 105°C

B. 130°C

C. 155°C

D. 180°C

Solution:

34. What particular motor class in which the operating temperature is 180°C?

A. Class H

B. Class F

C. Class A

D. Class B

Solution:

35. What are the basic components of a harmonic drive used in robot transmission system?

A. Wave generator

B. Flexspline

C. Circular spline

D. All of the choices

Solution:

36. What is the operating temperature of class B motor?

A. 200°C

B. 155°C

C. 130°C

D. 180°C

Solution:

37. What is the width of the pulse radiated by a fire control tracking radar?

A. Very thick

B. Narrow

C. Thick

D. Very narrow

Solution:

38. If the operating temperature is 155°C then it falls under what motor classification?

A. Class F

B. Class B

C. Class H

D. Class A

Solution:

39. How much percent is stray losses in dc machines?

A. 1%

B. 2%

C. 5%

D. 10%

Solution:

40. What are considered standard minimum distance between components on a chip?

A. 4 and 5 µm

B. 5 and 10 µm

C. 2 and 3 µm

D. 1 and 2µm

Solution:

41. For an advanced chip, the minimum distance between components is

A. 1 µm

B. 2 µm

C. 3 µm

D. 4 µm

Solution:

42. What are used to apply or remove power and to select a function or a circuit within a device?

A. Switch

B. Relay

C. Circuit control devices

D. Breaker

Solution:

43. What do you call a register on the CPU used for the temporary storage of data during arithmetic or logic operations?

A. Flip-flop

B. Accumulator

C. Memory

D. RAM

Solution:

44. What parameter specifies the value of voltage from cathode to cathode at which the SCR breaks into the avalanches region and begins to conduct heavily as in the pn junction diode?

A. Forward-breakover voltage

B. Reverse-breakover voltage

C. Break-over voltage

D. Stop-over voltage

Solution:

45. What type of servo system based on the same principle of error-signal generation where velocity is sensed, and the load is moving at the desired velocity?

A. Velocity servo

B. Rate servo

C. Speed servo

D. Controlled servo

Solution:

46. What is the term for the switch that disconnects the circuit completely at one position before the connection of the next position made?

A. Break-before-make

B. Make-before-break

C. Break-before-break

D. Make-before-make

Solution:

47. What is the identifying feature of a colpitts oscillator?

A. Split inductor

B. Split resistor

C. Split transformer

D. Split capacitor

Solution:

48. What instrument is used to measure the amount of active ingredients in the electrolyte of a battery?

A. Hygrometer

B. Voltmeter

C. Electrometer

D. Hydrometer

Solution:

49. What is the typical frequency range about the center frequency of a tunable magnetron?

A. ± 5%

B. ± 2%

C. ± 4%

D. ± 6%

Solution:

50. What is a gaseous tube that uses a poll of liquid mercury at its cathode?

A. Thyratron

B. Phanotron

C. Klystron

D. Ignitron

Solution:

51. What is the science of interaction or interconversion of electrical and acoustic phenomena?

A. Electrodynamics

B. Electrography

C. Electroanalysis

D. Electroacoustics

Solution:

52. What do you call the graphic record or the curve traced by the electrical activity of the brain as recorded by the electroencephalograph?

A. Electroform

B. Electrograph

C. Electrocardiogram

D. Electroencephalogram

Solution:

53. What imaging technique produces clear view of flowing blood or its blockage in narrow vessels?

A. Blood collation

B. Chemotography

C. Blood chemistry

D. Digital subtraction anglography

Solution:

54. What tube in a duplexer has the primary function of disconnecting the receiver?

A. Klystron tube

B. Magnetron tube

C. Thyratron tube

D. TR tube

Solution:

55. What requirement for a vacuum tube that does not exist for semiconductor?

A. Filament or heater voltage

B. Envelope

C. Grid

D. Screen

Solution:

56. An internal component of a klystron oscillator which modulates the velocity of the electrons.

A. the pair of buncher grids

B. The pair o f plates

C. The pair of catcher grids

D. The collector plate

Solution:

57. Given a power supply with a no load voltage of 12 volts and a full load voltage of 10 volts, what is the percentage of voltage regulation?

A. 17%

B. 20%

C. 80%

D. 83%

Solution:

58. A 50-µA meter movement has an internal resistance of 2 kΩ. What applied voltage is required to indicate half-scale deflection?

A. 0.01 volt

B. 0.10 volt

C. 0.005 volt

D. 0.05 volt

Solution:

59. The expression “voltage regulation” as it applies to a shunt-wound DC generator operating at a constant frequency refers to

A. Voltage output efficiency

B. Voltage in the secondary compared to the primary

D. Rotor winding voltage

Solution:

60. The expression “voltage regulation” as it applies to a generator operating at a constant frequency refers to

C. Source input supply frequency

D. Field frequency

Solution:

61. When an emergency transmitter uses 325 watts and a receiver uses 50 watts, how many hours can a 12.6 volt, 55 ampere-hour battery supply full power to both units?

A. 6 hours

B. 3 hours

C. 1.8 hours

D. 1.2 hours

Solution:

62. What is the total voltage when 12 nickel-cadmium batteries are connected in series?

A. 12 volts

B. 12.6 volts

C. 15 volts

D. 72 volts

Solution:

63. The turn ratio of a transformer is 1:20. When a 120 volt ac source is connected to its primary winding, the secondary voltage is

A. 120 volts

B. 1200 volts

C. 600 volts

D. 2400 volts

Solution:

64. A power transformer has a single primary winding and three secondary windings producing 5.0 volts, 12.6 volts, and 150 volts. Which of the three secondary windings will have the highest measured DC resistance

A. The 12.6 volt winding

B. The 5.0 volt winding

C. The 150 volt winding

D. All will have equal resistance values

Solution:

65. A special type of power supply filter choke inductance is inversely proportional to the amount of current flowing through it is a

A. AF choke

B. RF choke

C. Smoothing choke

D. Swinging choke

Solution:

66. What is the most suitable oscillator circuit for generating 1kHz?

A. Hartley oscillator

B. Colpitt’s oscillator

C. Wien bridge oscillator

D. Tuned collector oscillator

Solution:

67. How many the range of a thermocouple ammeter be increased?

A. By using a current transformer

B. By using a capacitor shunt

C. By using a current transformer and a capacitor shunt

D. By using a resistor shunt

Solution:

68. By what factor must the voltage of an ac circuit, as indicated on the scale of an ac voltmeter, be multiplied to obtain the average voltage value?

A. 0.707

B. 0.9

C. 1.414

D. 3.14

Solution:

69. What special type of diode is capable of both amplification and oscillation?

A. Point contact diodes

B. Zener diodes

C. Tunnel diodes

D. Junction diodes

Solution:

70. What is a common use of hot-carrier diode?

A. As balanced inputs SSB

B. As a variable capacitance in a automatic frequency control circuit

C. As a constant voltage reference in a power supply

D. As VHF and UHF mixers and detectors

Solution:

71. What is the normal operating voltage and current for a light-emitting diode?

A. 60 volts and 20 mA

B. 5 volts and 50 mA

C. 1.7 volts and 20 mA

D. 0.7 volts and 60 mA

Solution:

72. What type of bias is required for an LED to produce luminescence?

E. Reverse bias

A. Forward bias

B. Zero bias

C. Inductive bias

Solution:

73. What is the name of the semi-conductor IC that has a fixed pattern of digital data stored in its memory matrix?

A. RAM—Random-Access Memory

C. Register

D. Latch

Solution:

74. What would be the bandwidth of a good crystal lattice band-pass filter for a double-sideband phone emission?

A. 1 kHz at -6 dB

B. 500 Hz at -6 dB

C. 6 kHz at -6 dB

D. 15 kHz at -6 dB

Solution:

75. What technique can be used to construct low cost, high performance crystal lattice filters?

A. Splitting and tumbling

B. Tumbling and grinding

C. Etching and splitting

D. Etching and grinding

Solution:

76. What term defines a series of overshoots in a servo system?

A. Positioning

B. Variation

C. Hunting

D. Oscillating

Solution:

77. What is the acceptable ratio of back-to-forward resistance for a diode?

A. 2 to 1.5

B. Greater than 10 to 1

C. Less than 10 to 1

D. 3 to 2

Solution:

78. Packaging is required for what reason in IC production?

A. To meet storage requirement

B. To increase shelf-life

C. To dissipate heat

D. Ease of handling and protection from damage

Solution:

79. In radioactivity, what is the unit to measure the biological damage caused by radiation?

A. rem

C. lumen

D. reb

Solution:

80. What do you call the fine wires connecting the bonding pad to the chip t the external lead of the package?

A. Harness

B. Cables

C. Bonding wires

Solution:

81. What do you call the ratio between the intensity of magnetization produced in a substance, to the source of magnetizing force?

A. Magnetic resistivity

B. Magnetic conductivity

C. Magnetic susceptibility

D. Magnetic reluctivity

Solution:

82. What is a semi-conductor chip with electrodes (leads) extended beyond the wafer?

A. DICE

B. Flip chip

D. DIP

Solution:

83. What do you call an assembly of microcircuits or a combination of microcircuits and discrete components packaged as replacement?

A. Electronic module

B. Microcircuit module

C. PCB

D. Minielectronics

Solution:

84. In the operation of dry cells, we normally refer to the supply of current to load resistance where its current neutralizes the separated charges at the electrodes as ________>.

A. aligning the cells

B. charging the cells

C. discharging the cells

D. polarizing the cells

Solution:

85. What are the special class C amplifiers that are biased at 3 to 10 times the normal cutoff and used to generate frequency that is a harmonic of a lower frequency?

A. Frequency generators

B. Frequency stabilizers

C. Frequency multipliers

D. Frequency amplifiers

Solution:

86. Which of the following capacitors costs more per µF of capacitance?

A. Plastic

B. Mica

C. Paper

D. Electrolytic

Solution:

87. What capacitors are suitable for dc filter circuits?

A. Mica

B. Electrolytic

C. Ceramic

D. Plastic

Solution:

88. What is the other name or relative permittivity?

A. Dielectric strength

B. Breakdown voltage

C. Specific inductive capacity

Solution:

89. In RF amplifier with optimum coupling, what method provides the widest bandpass?

A. A parallel circuit

B. A swamping resistor

C. A parallel variable resistor

D. A dc coupling capacitor

Solution:

90. What is the operating condition of a circuit when no input signal is being applied to the circuit?

A. Neutral

B. Quantum

C. Quiescence

Solution:

A. 1.025 – 1.075

B. 1.200 – 1.500

C. 1.050 – 1.350

D. 1.280 – 1.300

Solution:

92. Which of the following are the basic elements in a 555 timer IC?

a) Two comparators

b) A flip-flop

c) A discharge transistor

d) A resistive voltage divider

A. A, B and D only

B. A, B and C only

C. B, C and D only

D. A, B, C and D

Solution:

93. In a sawtooth generator, increasing gate does what to linearity?

A. Nothing

B. Increases linearity

C. Blocks linearity

D. Decreases linearity

Solution:

94. Why are digital multimeters well suited for testing sensitive devices?

A. High current flow

B. It is portable and ruggedized

C. Because of its sensitivity

D. Current flows through the component is limited to 1 mA

Solution:

95. Compensation to an op-amp means ________ bandwidth and _________ slew rate.

A. reduced, increased

B. reduced, reduced

C. increased, reduced

D. increased, increased

Solution:

96. Boolean algebra is based on the assumption that most quantities have ______ possible states.

A. four

B. two

C. three

D. single

Solution:

97. Which of the following are types of resonant LC oscillators?

A. Colpitts

B. Clapp

C. Hartley

D. Armstrong

E. Crystal-controlled

A. A, B, C and E only

B. A, B, C and D only

C. B, C, D and E only

D. A, B, C, D and E

Solution:

98. What does the base or radix of a number system tell you about the system?

A. Number of units used in the system

B. Number of items used in the system

C. Number of symbols used in the system

D. Number of numerals used in the system

Solution:

99. The specific gravity of a lead-acid battery is a measure of its ______

A. battery life

B. operating temperature

C. state of charge

D. rate of discharge

Solution:

100. In active filter, what type of filter passes a range of frequency and a certain higher frequency?

A. Band-stop

B. High pass

C. Low pass

D. Band-pass

Solution:

### Complete List of Electronics Engineering Pre-Board Exams

Electronics Engineering Pre-Board Exams
Module 1: Electronics Engineering Exam 1                   Answer key: EXAM 1
Module 2: Electronics Engineering Exam 2                   Answer key: EXAM 2
Module 3: Electronics Engineering Exam 3                   Answer key: EXAM 3
Module 4: Electronics Engineering Exam 4                   Answer key: EXAM 4
Module 5: Electronics Engineering Exam 5                   Answer key: EXAM 5
Module 6: Electronics Engineering Exam 6                   Answer key: EXAM 6
Module 7: Electronics Engineering Exam 7                   Answer key: EXAM 7
Module 8: Electronics Engineering Exam 8                   Answer key: EXAM 8
Module 9: Electronics Engineering Exam 9                   Answer key: EXAM 9
Module 10: Electronics Engineering Exam 10                   Answer key: EXAM 10