Electronics Engineering Mastery Test 11: ECE Pre-Board Practice Exam

This is the Electronics Engineering Mastery Test 11 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 11

⇐ Electronics Engineering Mastery Test 10: ECE Pre-Board

Choose the letter of the best answer in each questions.

1. A power derating factor of 3.33 mW/°C above 50°C means that

A. you must decrease the DC power dissipation rating by 3.33 mW for every 1°C rise in the operating temperature above 50°C

B. you will end up getting a power of 3.33 mW if temperature goes beyond 50°C

C. you must increase the DC power dissipation rating by 3.33 mW for every 1°C rise in the operating temperature above 50°C

D. your zener diode will dissipate a nominal DC power of 3.33 mW for temperature above 50°C

2. When you first turn a power supply on, the filter capacitor initially acts as a short circuit thus creating a high initial current that can possibly destroy your rectifier diodes. What is the best way to limit the said current but without sacrificing the output voltage?

A. use a large-value series current-limiting resistor

B. use large-value filter capacitors

C. use inductive filters instead of capacitive filters

D. don’t turn off your power supply

3. The electromagnetic force induced between a varying magnetic field and a stationary conductor.

A. Mutually induced EMF

B. Self-induced EMF

C. Electro statically induced EMF

D. Statically induced EMF

4. A wire has a resistance of 5 Ω at room temperature and a temperature coefficient α = 4 × 10-3/°C. Calculate the wire resistance if the temperature rises by 75°C.

A. 6.5 Ω

B. 6.1 Ω

C. 6 Ω

D. 6.16 Ω

5. A combination of two charges with equal charge magnitude but opposite signs.

A. magnetic dipole

B. static dipole

C. dynamic dipole

D. electric dipole

6. If a dc electromagnetic of 10-V produces a steady-state current of 100-mA in a 100 Ω coil, how much will the current be after 0.2 sec?

A. 63 mA

B. 100 mA

C. 37 mA

D. 200 Ma

7. What is the time constant of a 20-H coil having 100 Ω of series resistance?

A. 5 s

B. 0.5 s

C. 0.2 s

D. 20 ms

8. If the RC time constant is given to be 1 s, how long will it take for the voltage to drop from 100 V to 50 V?

A. 0.63 s

B. 0.37 s

C. 0.5 s

D. 0.7 s

9. The effect of little change in magnetic flux density when magnetic field intensity increases.

A. Retentivity

B. Coercivity

C. Saturation

D. Permeability

10. A series resonant circuit at 0.2 MHz develops 100 mV across a 250 µH coil with a 2 mV input. Calculate Q.

A. 50

B. 25

C. 100

D. 200

11. A point in magnet where the intensity of magnetic lines of force is a maximum.

A. North Pole

B. Saturation Point

C. Coercive point

D. Magnetic pole

12. An oscillator circuit that has two capacitors and one inductor on its feedback network

A. Colpitts

B. Clapp

C. Hartley

D. Pierce Crystal

13. The ability of a substance of getting magnetized is called

A. Retentivity

B. Permeability

C. Coercivity

D. Susceptibility

14. A 12 volt battery is connected to a 5 cm, 350 turn coil with resistance of 15-Ω. What is the field strength produced in Oe?

A. 70

B. 280

C. 56

D. 353

15. A magnetic material has a relative permeability of 500. What is the absolute permeability of the material in cgs system?

A. 500

B. 630 H/m

C. 500 G/Oe

D. 630 x 10-6 G/Oe

16. The reciprocal of reluctance corresponds to what in electric circuits?

A. Permeance

B. Admittance

C. Impedance

D. Conductance

17. A material with negative temperature coefficient means

A. Its resistance will increase as temperature increases

B. Its resistance will decrease as temperature decreases

C. Its resistance will increase as temperature decreases

D. Its resistance will decrease as temperature increases

18. A 12-V battery with a capacity of 100 A-hr is used to supply 300-W electronic equipment and a 25 W light. How long will this battery last?

A. 7.38 hours

B. 3.69 hours

C. 5.22 hours

D. 2.61 hours

19. The physical motion that is due to the forces of magnetic fields

A. Repulsion

B. Attraction

C. Motor Action

D. Rotation

20. Which of these statements is FALSE about the relationship of the magnetic force on a moving charge?

A. A magnetic force does not point in the direction of the field or in the direction of the charge’s velocity

B. A magnetic force is exerted on a moving electric charge

C. No magnetic force is exerted on a charge at rest

D. A magnetic force is exerted on a charge moving along the direction of the magnetic field

21. Indicate which of the following statements is FALSE.

A. Capacitive reactance is a measure of the reaction of C to a change in voltage

B. RC time constant is a measure of the reaction of C to a change in voltage

C. The concept of reactance is useful for both sine wave AC circuits and non-sinusoidal waveforms

D. The method of time constant is used to analyze both sinusoidal and non-sinusoidal waveforms

22. It is the ability of an insulator to concentrate electric flux

A. Permeability

B. Susceptibility

C. Permittivity

D. Retentivity

23. It is commonly used for precision wire-wound resistors, which do not change resistance when the temperature increases

A. carbon

B. aluminum

C. constantan

D. iron

24. Which of the following statements is true about the force on a current-carrying straight conductor in a magnetic field?

A. With the conductor at 90°, the reaction between two magnetic fields is minimum

B. With the conductor at 0°, there is no effect between them

C. With the conductor is at angle between 0° and 90°, only the parallel component is effective

D. A motor action can be produced if the conductor is placed parallel to the magnetic field

25. It is known as the breakdown voltage of a dielectric material.

A. relative permittivity

B. dielectric strength

C. velocity reduction ratio

D. velocity factor

26. Find the value and tolerance of a resistor having bands of the following: Red, Violet, Green, Silver.

A. 27 MΩ ±10%

B. 2.7 MΩ ±10%

C. 27 kΩ ±10%

D. 2.7 kΩ ±10%

27. Thevenin’s theorem replaces a complicated circuit facing a load by an

A. ideal voltage source and parallel resistor

B. ideal voltage source and series resistor

C. ideal current source and parallel resistor

D. ideal current source and series resistor

28. In a sine wave AC circuit with inductive reactance, the

A. phase angle of the circuit is always 45°

B. voltage across the inductance must be 90° out of phase with the applied voltage

C. current through the inductance lags its induced voltage by 90°

D. current through the inductance and voltage across it are 180° out of phase

29. What negative feedback type increases both the input and output impedances of an amplifier?

A. Voltage-shunt

B. Current-shunt

C. Voltage-series

D. Current-series

30. A linear circuit is one whose parameters (e.g. resistances, etc)

A. change with change in current

B. change with change in voltage

C. do not change with voltage and current

D. are bilateral

31. Ten volts is applied across R1, R2, and R3 is series, producing 1 A in the series circuit. R1 equals 6 Ω and R2 equals 2 Ω. Therefore, R3 equals

A. 2 Ω

B. 10 Ω

C. 4 Ω

D. 12 Ω

32. A 0.5-C charge is moving at ratio of 5 cm/s. What is the current at 2 sec?

A. 0.25 A

B. 10 A

C. 0.025 A

D. 0.10 A

33. The fifth strip of a precision film resistor color code represents

A. tolerance

B. temperature

C. failure rate

D. multiplier

34. Find the value of a capacitor in picofarads having the following color bands: Yellow, Violet, Brown, Black, Yellow

A. 47 pF ±10%

B. 470 pF ±10%

C. 47 pF ±20%

D. 470 pF ±20%

35. A meter-sensitivity control in a test instrument would probably be:

A. A set of switchable, fixed resistors

B. A linear-taper potentiometer

C. A logarithmic-taper potentiometer

D. A wirewound resistor

36. At what temperature a magnetic material will lose its ferromagnetic properties?

A. Curie temperature

B. Absolute temperature

C. ambient temperature

D. room temperature

37. What is Coulomb’s first law of electrostatics?

A. Like poles repel unlike poles attract each other

B. Like charges repel unlike charges attract each other

C. Unlike poles repel and like poles attract each other

D. Unlike charges repel and like charges attract each other

38. A volume control in a stereo compact-disc player would probably be:

A. A set of switchable, fixed resistors

B. A linear-taper potentiometer

C. A logarithmic-taper potentiometer

D. A wirewound resistor

39. A conductor in which two oscillating circuit have the same resonant frequency is called

A. Gimmick

B. Synthony

C. Puff

D. Wet contact

40. The effect UV radiation that discharges a negatively charged body in a vacuum is called

A. Joule effect

B. Hallwachs effect

C. Hall Effect

D. Joshi effect

41. If a wire conductor of 0.1 resistance is doubled in length, its resistance becomes

A. 0.01 Ω

B. 0.02 Ω

C. 0.2 Ω

D. 0.05 Ω

42. On what basis is the size of the filter capacitor selected?

A. short RC time constant

B. power rating

C. voltage rating

D. long RC time constant

43. Those magnetic materials are best suited for making armature and transformer cores which have _____ permeability and ______ hysteresis loss.

A. high, high

B. high, low

C. low, low

D. low, high

44. A capacitor charged to 100 V and is then switched across a resistor. When the voltage across the capacitor has fallen to 14 V, the duration of the discharge as measured in time constants, is approximately

A. 0.3

B. 2.0

C. 1.0

D. 2.5

45. Preventing one material from affecting one another through their common electric or magnetic hysteresis

A. grounding

B. Hall Effect

C. shielding

D. limiting

46. If the tolerance color is violet, this means a tolerance of

A. 0.1%

B. 0.5%

C. 0.25%

D. 1%

47. A fully charged lead-acid battery will indicate a specific gravity reading between

A. 1.175 to 1.200

B. 1.225 to 1.250

C. 1.200 to 1.225

D. 1.275 to 1.300

48. Find the phase angle between the voltages across the current through the circuit when XC is 25 ohms, R is 100 ohms and XL is 100 ohms are in series.

A. 53.1 degrees with the voltage lagging the current

B. 36.9 degrees with the voltage leading the current

C. 53.1 degrees with the voltage leading the current

D. 36.9 degrees with the voltage lagging the current

49. For Kirchhoff’s voltage law, circuits are divided into which of the following?

A. Series-parallel circuits

B. Nodes

C. Ohms

D. Loops

50. The ability of a conductor to pass or the opposite of resistance?

A. Reactance

B. Capacitance

C. Resistance

D. Conductance

51. The resistance of a coil wire increases from 40 Ω at 10°C to 48.25 Ω at 60°C. Find the temperature coefficient at 0°C of the conductor material.

A. 0.0043

B. 0.00493

C. 0.00393

D. 0.0053

52. A length of wire has a resistance of 6 Ω. What is the resistance of wire of the same material three times as long as twice the cross-sectional area?

A. 36 Ω

B. 12 Ω

C. 9 Ω

D. 01 Ω

53. Which of the following statements is TRUE?

A. An Ideal current source cannot be in parallel with a short circuit

B. An ideal voltage source can be in parallel with an open circuit

C. An ideal current source can be in series with an open circuit

D. An ideal voltage source cannot be in series with an ideal current source

54. Halving the cross-sectional area of a conductor will

A. Not affect the resistance

B. Half the resistance

C. Quarter the resistance

D. Double the resistance

55. Given a power supply with a full load voltage of 200 volts and a regulation of 25%, what is the no load voltage?

A. 150 volts

B. 240 volts

C. 160 volts

D. 250 volts

56. A coil has 6,000 turns of wire and a resistance of 380 Ω. The coil is rewound with the same quantity (weight) of wire, but has 13,400 turns. How many Ω will the new coil have?

A. 1895 Ω

B. 1905 Ω

C. 1825 Ω

D. 1792 Ω

57. What is the average power dissipated by an electric heater with resistance of 50 Ω drawing a current of 20 sin 30t A?

A. 0 kW

B. 10 kW

C. 14.14 kW

D. 20 Kw

58. Those materials are well suited for making permanent magnets which have ______ retentivity and _____ coercivity.

A. low, low

B. high, high

C. low, high

D. high, low

59. A backwards-working electric motor is best described as:

A. An inefficient, energy-wasting device

B. A motor with the voltage connected the wrong way

C. An electric generator

D. A magnetic-field generator

60. What measurements are required to determine the phase angle of a single-phase circuit?

A. The power in watts consumed by the circuit

B. The frequency, capacitance and inductance

C. The power in watts, voltage and current

D. The resistance, current and voltage

61. An AC circuit consisting of a capacitor, an inductor and a resistor in series is a resonant when the

A. in-phase current equals the out-of-phase current

B. maximum current passes through the circuit

C. power dissipation is minimum

D. power factor is zero

62. What is the value of the peak factor for a pure sine wave?

A. 1.414

B. 0.637

C. 0.707

D. 1.11

63. The conductance and inductive susceptance of a circuit have the same magnitude. What is the power factor of the circuit?

A. 1

B. 0.707

C. 0.5

D. 0.866

64. A circuit has a resonant frequency of 455 KHz and a bandwidth of 57.2 KHz. Find the Q of the circuit.

A. 795

B. 79.5

C. 0.795

D. 7.95

65. In a parallel-resonant circuit, what is the relationship between impedance and current?

A. Minimum impedance, minimum current

B. Minimum impedance, maximum current

C. Maximum impedance, minimum current

D. Maximum impedance, maximum current

66. A 15 µC point charge is located on the y-axis at (0, 0.25). A second charge of 10 µC is located on the x-axis at (0.25, 0). If the two charges are separated by air, what is the force between them?

A. 0.0982 N

B. 33.93 N

C. 0.341 N

D. 10.79 N

67. A cell connection, providing a higher voltage than a single cell with no increase in current.

A. Ground connected

B. Parallel connected

C. Series connected

D. Series-parallel connected

68. A power transforming device, one that converts energy into some other form

A. Converter

B. Transducer

C. Transformer

D. Transmuter

69. Refers to charging and discharging of secondary cells?

A. Re-charging of cell

B. Re-aligning of cell

C. Polarizing of cell

D. Cycling of cell

70. What static electricity can be produced by rubbing fur on a rubber, amber, or plastic rod?

A. Resinous static electricity

B. Positive static electricity

C. Vitreous static electricity

D. Negative static electricity

71. What do you call the space between and around charged bodies?

A. Magnetic field

B. Electromotive force

C. Electromagnetic field

D. Electrostatic field

72. In RC circuits, the time constant indicates the time it takes a capacitor to charge up to what percent of the charging voltage?

A. 100%

B. 63%

C. 67%

D. 31%

73. A 0.01 m by 0.02m solar cell has a conversion efficiency of 9%. The maximum power rating of the device is

A. 18 mW

B. 180 mW

C. 1800 kW

D. 180 Kw

74. A practical type of capacitor used to demonstrate static electricity.

A. Mycalex

. Muller tube

C. Geiger counter

D. Leyden jar

75. What does a gold third band represent?

A. 0.01 multiplier

B. 5% tolerance

C. a 10% tolerance

D. a 0.1 multiplier

76. What does a fifth band on a resistor indicate?

A. reliability

B. sensitivity

C. life

D. no fifth band

77. DC motors and stepper motors are mainly used in robots instead of AC motors because they can

A. be electronically controlled

B. be operated by electric pulses

C. withstand large overloads

D. run at varying speed

78. The production of hydrogen gas caused by a portion of a charge current breaking down the water in the electrolytes

A. Electrolysis

B. Hydrogenation

C. Hydrolysis

D. Gassing

79. Length of twisted two-conductor cable used as a variable capacitive load in which, untwisting and separating the individual conductors vary the capacitance.

A. Gimmick

B. Syntony

C. Puff

D. Wet contact

80. The length of cylindrical capacitor is 10mm. The outer diameter of its single core cable conductor is 3 mm surrounded by a paper insulation of outer diameter 6 mm. What is its capacitance?

A. 2.0 µF

B. 2.5 µF

C. 2.0 pF

D. 2.5 Pf

81. What electrical quantity is measured by a watt-hour meter?

A. Current

B. Energy

C. Voltage

D. Power

82. The phenomenon whereby current in a gas changes as a result of irradiation by light is called

A. Joule effect

B. Hall Effect

C. Joshi effect

D. Hallwachs Effect

83. Three capacitors A, B and C are charged as follows: A = 10 µF at 100 V, B = 15 µF at 150 V and C = 25 µF at 200 V. They are then connected in parallel with terminals of like polarity together. What is the voltage across the combination?

A. 156 V

B. 256 V

C. 165 V

D. 265 V

84. A disadvantage of mercury cells and batteries is that:

A. They don’t last as long as other types.

B. They have a flat discharge curve.

C. They pollute the environment.

D. They need to be recharged often.

85. How long does it take for an initial charge of 20 VDC to decrease to 0.37 VDC in a 0.01 µF capacitor when a 2 MΩ resistor is connected across it?

A. 0.08 second

B. 0.4 second

C. 0.6 second

D. 0.2 second

86. If a resistance to which a constant voltage is applied is halved, what power dissipation will result?

A. Doubled

B. Quadrupled

C. Halved

D. Stay the same

87. A substance with high retentivity is best suited for making:

A. An ac electromagnet

B. A dc electromagnet

C. An electrostatic shield

D. A permanent magnet

88. A significant advantage, in some situations, of a toroidal coil over a solenoid is:

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

89. The process of converting chemical energy into electrical energy in a cell.

A. Electron flow

B. Electrolysis

C. Polarization

D. Electrochemical action

90. The portion of apparent power dissipated in a circuit

A. Phase power

B. True power

C. Power factor

D. Apparent power factor

91. Waves in alternating current can involve

A. regular changes in voltages levels

B. regular changes in current levels

C. regular changes in the direction of the electron flow

D. all of the above

92. In a triangular or sawtooth waveform, the RMS is how many times the peak value?

A. 0.577

B. 0.500

C. 0.707

D. 0.15

93. For an inductor or coil, which of the following indicates how low the losses are?

A. Quality factor

B. Inductive reactance

C. Power factor

D. Impedance

94. A certain wire has a resistance R. The resistance of another wire identical with the first except for having twice its diameter is

A. 4R

B. 2R

C. R/2

D. R/4

95. Copper is the second best conductor of electricity with ______ free electrons per in3.

A. 1.68 x 1024

B. 1.64 x 1024

C. 1.6 x 1024

D. 1.66 x 1024

96. A resistor with the color-coded value of 100 Ω and ±20 percent tolerance can have an actual resistance between

A. 80 and 120 Ω

B. 98 and 102 Ω

C. 90 and 110 Ω

D. 100 and 120 Ω

97. What is the basic purpose of all electrical and electronic system that are designed and built?

A. to manipulate information

B. to do work

C. to do work and manipulate information

D. to generate information

98. What is the typical leakage resistance of a paper capacitor?

A. 109 Ω

B. 105 Ω

C. 1011 Ω

D. 1010 Ω

99. Tantalum electrolytic capacitor has a typical value that ranges from

A. 1 µF to 22000 µF

B. 5 pF to 1 µF

C. 1 µF to 1000 µF

D. 1 nF to 100 µF

100. A transformer has 500 turns in the primary and 1500 in the secondary. Assuming no losses, if 45 V is applied to the primary what is the voltage developed in the secondary?

A. 180 V

B. 13.5 V

C. 135 V

D. 90 V

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