Module 3 - Question Bank - IGNORE

Question 1

1. A capacitor is fully charged after 25 seconds to a
   battery voltage of 20 Volts. The battery is replaced with a
   short circuit. What will be the voltage across the capacitor
   after one time constant?
   a) 12.64 volts
   b) 7.36 volts
   c) 0 volts

Answer 1

b) 7.36 volts

Question 2

2. The voltage rating of a capacitor is
   a) the max voltage that can be constantly applied
   b) the min voltage required to charge
   c) the normal operating voltage

Answer 2

a) the max voltage that can be constantly applied

Question 3

3. The relative permittivity of a capacitor is
   a) the relative permittivity of the dielectric in relation to
   a vacuum
   b) the permittivity of dielectric in relation to dry air
   c) the permittivity of the dielectric

Answer 3

a) the relative permittivity of the dielectric in relation to
a vacuum

Question 4

4. Magnetic inclination is the least at the
   a) poles
   b) equator
   c) isoclines

Answer 4

b) equator

Question 5

5. Ferromagnetic materials can be magnetized
   a) within a band of temperatures
   b) above a certain temperature
   c) below a certain temperature

Answer 5

c) below a certain temperature

Question 6

6. Faradays Law States that
   a) the magnitude of the EMF is directly proportional to the rate of change of flux
   b) the magnitude of the EMF is indirectly proportional to the rate of change of flux
   c) the magnitude of the EMF is directly proportional to the magnetic flux

Answer 6

a) the magnitude of the EMF is directly proportional to the rate of change of flux

Question 7

7. To reduce eddy currents in a transformer you would
   a) reduce the thickness of laminations in the magnetic core
   b) Increase the thickness of laminations in the magnetic core
   c) Reduce the number of turns on the primary winding

Answer 7

a) reduce the thickness of laminations in the magnetic core

Question 8

8. A transformer has an input of 400V and a ratio of 2:1.
   If the transformer is delta / star wound, what will the line
   voltage output be?
   a) 115V
   b) 200V
   c) 346V

Answer 8

c) 346V

Question 9

9. What is the phase difference in a circuit with 100V,
   drawing 0.5 amps, consuming 50 Watts?
   a) 45°
   b) 90°
   c) 0°

Answer 9

c) 0°

Question 10

10. In an A.C circuit, what happens if frequency is
    reduced?
    a) Capacitive elements may be damaged
    b) Inductive elements may be damaged
    c) There will be no effect

Answer 10

b) Inductive elements may be damaged

Question 11

11. A Transformer with 115v primary voltage and a ratio
    of 5:1 is supplying a landing light (load 24v 45 amps) is
    used, what is the current drawn?
    a) 205 amps
    b) 9 amps
    c) 4.5 amps

Answer 11

b) 9 amps

Question 12

12. A Transformer has 4500 secondary turns and 750
    primary turns. Its turns ratio is
    a) 1:6
    b) 6:1
    c) 1/6

Answer 12

b) 6:1

Question 13

13. Two inductive coils are placed in close proximity with
    each other at 90 degrees. The number of flux linkages is
    a) 0
    b) maximum positive
    c) maximum negative

Answer 13

a) 0

Question 14

14. A high pass filter will?
    a) allow frequencies above a certain value to pass
    b) allow frequencies below a certain value to pass
    c) allow frequencies within a range to pass

Answer 14

a) allow frequencies above a certain value to pass

Question 15

15. If you apply this waveform to this circuit, what is the
    output across the capacitor?
    a) Zero
    b) Pulsed negative
    c) Pulsed positive

Answer 15

c) Pulsed positive

Question 16

16. What value is the same as the equivalent D.C.
    heating effect?
    a) Root Mean Square
    b) Average
    c) Peak

Answer 16

a) Root Mean Square

Question 17

17. What is the relationship between the voltage and the
    current in an A.C circuit containing resistance &
    inductance?
    a) Current leads voltage by up to 90°
    b) Current lags voltage by up to 90°
    c) Current lags voltage by 90°

Answer 17

b) Current lags voltage by up to 90°

Question 18

18. What shape is the waveform when the input pulse
    and the time base are unequal?
    a) Square
    b) Rectangular
    c) Saw tooth

Answer 18

b) Rectangular

Question 19

19. A sine wave has 5 amps RMS value. What is the
    peak value?
    a) 6.37 amps
    b) 7.07 amps
    c) 10 amps

Answer 19

b) 7.07 amps

Question 20

20. In this circuit
    a) current leads voltage
    b) current lags voltage
    c) current = voltage

Answer 20

a) current leads voltage

Question 21

21. Decreasing the field current in a shunt motor will
    a) increase speed and decrease torque
    b) increase speed and increase torque
    c) decrease speed and increase torque

Answer 21

b) increase speed and increase torque

Question 22

22. Power factor relates to
    a) true power and apparent power
    b) KW and KVAR
    c) horsepower and Watts

Answer 22

a) true power and apparent power

Question 23

23. In a delta-connected generator
    a) line volts = phase volts, line current = root 3 times phase current.
    b) line volts = phase volts, line current = phase current divided by root 3
    c) line voltage = root 3 times phase voltage, line current = phase current

Answer 23

a) line volts = phase volts, line current = root 3 times phase current.

Question 24

24. If current lags voltage by 90°, the circuit is
    a) capacitive
    b) resistive
    c) inductive

Answer 24

c) inductive

Question 25

25. In a 3 phase motor, if 1 phase is lost, the motor
    a) remains at the same speed
    b) runs at 1 third speed
    c) runs at 2 thirds speed

Answer 25

a) remains at the same speed

Question 26

26. A three-phase motor has the windings
    a) 120° apart
    b) 90° apart
    c) 180°apart

Answer 26

a) 120° apart

Question 27

27. When measuring the phase and line voltages of a generator, it was found that line and phase voltages were equal. The generator is?
    a) delta wound
    b) star wound.
    c) either delta or star wound

Answer 27

a) delta wound

Question 28

28. To change the direction of a 3-phase induction motor
    you would
    a) swap two of the stator connections
    b) swap all of the input connections
    c) remove one of the input connections

Answer 28

a) swap two of the stator connections

Question 29

29. To calculate generator output you need to know the
    a) armature speed and number of series conductors
    b) armature speed and number of parallel conductors
    c) armature speed and field strength

Answer 29

c) armature speed and field strength

Question 30

30. In a shunt motor, if you reverse both field current and armature current, the motor will
    a) stop
    b) change direction
    c) continue to run in the same direction

Answer 30

c) continue to run in the same direction

Question 31

31. The permanent magnet in an A.C generator induces
    a) A.C. in the exitor generator
    b) D.C. in the exitor generator
    c) A.C. in the main generator

Answer 31

a) A.C. in the exitor generator

Question 32

32. What does the following circuit represent?

a) Integrator
b) Low pass filter
c) Differentiator

Answer 32

c) Differentiator

Question 33

33. What charge does the nucleus of an atom possess?
    a) Positive
    b) Negative
    c) Neutral

Answer 33

a) Positive

Question 34

34. What is the maximum number of electrons in shell N
    of an atom?
    a) 16
    b) 32
    c) 18

Answer 34

b) 32

Question 35

35. Two 10V, 20 Ah batteries are connected in parallel and connected across a 10-ohm load. How long could they supply normal current before the voltage begins to decay?
    a) 20 hours
    b) 4 hours
    c) 40 hours

Answer 35

c) 40 hours

Question 36

36. A 10 V battery supplies a resistive load of 10 ohms for
    1 minute. What is the power supplied
    a) 100 W
    b) 10 VA
    c) 10 W

Answer 36

c) 10 W

Question 37

37. A 10V battery supplies a resistive load of 10 ohms for
    1 minute. What is the work done?
    a) 60J
    b) 10J
    c) 600J

Answer 37

c) 600J

Question 38

38. Three capacitors 10 microfarads, 10 nanofarads and
    10 millifarads are connected in parallel. What is the total
    capacitance?
    a) 10.01001mF
    b) 111mF
    c) 1.001001mF

Answer 38

a) 10.01001mF

Question 39

39. If a 1mF capacitor has a potential difference across it of 5V what is the energy stored?
    a) 12.5 J
    b) 12.5 mJ
    c) 25 mJ

Answer 39

b) 12.5 mJ

Question 40

40. A capacitor is fully charged after 25 seconds to a battery voltage of 20 V. The battery is replaced with a short circuit. What will be the voltage across the capacitor after 1 time constant?
    a) 12.64 V
    b) 7.36 V
    c) 0 V

Answer 40

b) 7.36 V

Question 41

41. Glass is an example of a
    a) paramagnetic material
    b) diamagnetic material
    c) coercive material

Answer 41

b) diamagnetic material

Question 42

42. Which of the following is absolute permeability?
    a) µ
    b) µo
    c) µr

Answer 42

a) µ

Question 43

43. A solenoid of 10 turns per meter carries a current of
    5A. If the current is reduced to 2.5A, how many turns
    would be required to maintain the same magnetic field?
    a) 5
    b) 50
    c) 20

Answer 43

c) 20

Question 44

44. The point of coercivity occurs when the
    a) magnetizing force applied causes the material to become magnetically saturated.
    b) magnetic flux is zero even though a magnetizing force is being applied.
    c) magnetizing force reaches a peak positive or negative value.

Answer 44

b) magnetic flux is zero even though a magnetizing force is being applied.

Question 45

45. What is the mutual inductance if two coils of 10mH and 500mH have 90% of the flux transferred from one to the other?
    a) 4.5mH
    b) 459mH
    c) 63mH

Answer 45

c) 63mH

Question 46

46. An inductor has 1,000 turns of wire and a cross sectional area of 0.001m2. If the core has a permeability of 0.000,001 and the coil is 0.1m what is the value of the inductor
    a) 10mH
    b) 100microH
    c) 100mH

Answer 46

a) 10mH

Question 47

47. Three inductors 10 mH, 5 mH and 20 mH are connected in parallel. What is the total inductance?
    a) 35mH
    b) 2.86mH
    c) Without knowing the coupling factor the total inductance cannot be found

Answer 47

b) 2.86mH

Question 48

48. If the current reaches a maximum through an inductor of 2A in 15 secs, what is the current after 3 secs?
    a) 1.26A
    b) 0.63A
    c) 1A

Answer 48

a) 1.26A

Question 49

49. If the phase voltage in a star connected generator is 200V what will be the line voltage?
    a) 115V
    b) 200V
    c) 346V

Answer 49

c) 346V

Question 50

50. A generator is labeled as having 115V/200V, 20A and PF 0.8. What is the apparent power in each line that the generator can produce?
    a) 2.3kW
    b) 2.3kVA
    c) 4kVA

Answer 50

c) 4kVA

Question 51

51. A starter generator has a
    a) low resistance series field and a low resistance shunt field
    b) low resistance series field and a high resistance shunt field
    c) high resistance series field and a low resistance shunt field

Answer 51

b) low resistance series field and a high resistance shunt field

Question 52

52. Thermocouple harnesses are made from the same materials as the thermocouple so that
    a) they will not corrode
    b) mini junctions are not formed
    c) the resistance is not increased beyond limits

Answer 52

b) mini junctions are not formed

Question 53

53. An oxygen molecule is made up of
    a) two oxygen atoms sharing electrons
    b) two oxygen atoms sharing neutrons
    c) two oxygen atoms sharing protons

Answer 53

a) two oxygen atoms sharing electrons

Question 54

54. A capacitor in a single phase AC motor is to
    a) prevent spikes
    b) block DC
    c) provide a phase shift

Answer 54

c) provide a phase shift

Question 55

55. The slip speed of an induction motor is
    a) stator speed - rotor speed
    b) stator speed + rotor speed
    c) stator speed / rotor speed

Answer 55

a) stator speed - rotor speed

Question 56

56. The primary winding of a 3-phase transformer
    a) is delta wound
    b) is star wound
    c) could be either delta or star wound

Answer 56

c) could be either delta or star wound

Question 57

57. The symbol for flux density is
    a) H
    b) B
    c) ø

Answer 57

b) B

Question 58

58. A galvanometer measures
    a) millivolts
    b) megohms
    c) milliamps

Answer 58

c) milliamps

Question 59

59. A battery rated at 40 Ah will supply 200 mA for
    a) 200 hours
    b) 5 hours
    c) 20 hours

Answer 59

a) 200 hours

Question 60

60. The unknown resistance R in the wheatstone bridge shown is
    a) 1 ohm
    b) 4 ohms
    c) 16 ohms

Answer 60

b) 4 ohms

Question 61

61. Which of the following materials is easiest to
    magnetize?
    a) Soft iron
    b) High grade steel
    c) Cast iron

Answer 61

a) Soft iron

Question 62

62. AC generators are rated in
    a) kVARs
    b) kW
    c) kVA

Answer 62

c) kVA

Question 63

63. To find which end of an electromagnet is the north pole, use the
    a) Fleming’s Left Hand Rule
    b) Right Hand Clasp Rule
    c) Cork Screw Rule

Answer 63

b) Right Hand Clasp Rule

Question 64

64. A capacitor with double the area and double the dielectric thickness will have
    a) double the capacitance
    b) half the capacitance
    c) the same capacitance

Answer 64

c) the same capacitance

Question 65

65. In a transformer, if the rate of change of current increases, the mutual inductance will
    a) increase
    b) decrease
    c) remain the same

Answer 65

c) remain the same

Question 66

66. If the brake coil on an actuator motor goes open circuit, the actuator will
    a) over-ride its mechanical stops
    b) stop
    c) run slower

Answer 66

b) stop

Question 67

67. The frequency of the output of a 4 pole generator is 400 Hz. The generator is turning at
    a) 12000 RPM
    b) 6000 RPM
    c) 3000 RPM

Answer 67

a) 12000 RPM

Question 68

68. What is the wave shape of the x-axis input of a traversing oscilloscope image?
    a) square
    b) rectangular
    c) triangular

Answer 68

c) triangular

Question 69

69. An inductance/resistance motor is
    a) better than a capacitance motor
    b) restricted to low loads only
    c) less efficient than a capacitance motor

Answer 69

c) less efficient than a capacitance motor

Question 70

70. The voltage at point A is
    a) 7 V
    b) 21 V
    c) 28 V

Answer 70

a) 7 V

Question 71

71. A 4:1 step down transformer draws 115 V and 1 A.
    The output power will be
    a) 28.5 V at 4 A
    b) 28.5 V at 16 A
    c) 460 V at 0.25 A

Answer 71

a) 28.5 V at 4 A

Question 72

72. The voltage induced in the stator of an AC generator
    is produced by
    a) a fixed magnetic field
    b) a rotating magnetic field
    c) an alternating field

Answer 72

b) a rotating magnetic field

Question 73

73. A low frequency supply
    a) may damage inductive components
    b) will have no effect on inductive components
    c) will make the circuit operate faster due to the reduced impedance

Answer 73

a) may damage inductive components

Question 74

74. A zinc-carbon battery life depends upon
    a) the purity of the carbon rod
    b) the amount of zinc
    c) the amount of the electrolyte paste

Answer 74

b) the amount of zinc

Question 75

75. When checking the s.g. of the electrolyte in a lead acid battery, you should
    a) check all cells because they may be different
    b) check only the no. 1 cell because it is the master cell
    c) check any cell because they will all be the same

Answer 75

a) check all cells because they may be different

Question 76

76. If electrons are added to an atom it becomes
    a) a positive ion
    b) a negative ion
    c) a neutral ion

Answer 76

b) a negative ion

Question 77

77. An element whose atoms have fewer than 4 electrons
    in their valency shell are
    a) good conductors
    b) good insulators
    c) semiconductors

Answer 77

a) good conductors

Question 78

78. In a purely resistive AC circuit, the current vector is
    a) in phase with the voltage vector
    b) +90^ out of phase with the voltage vector
    c) -90^ out of phase with the voltage vector

Answer 78

a) in phase with the voltage vector

Question 79

79. The PD at the terminals of an open circuit battery with a small internal resistance will be
    a) more than the EMF
    b) less than the EMF
    c) the same as the EMF

Answer 79

c) the same as the EMF

Question 80

80. The diagram shows a 200 V long shunt generator. What is the voltage dropped across the series resistor?
    a) 200 V
    b) 0.12 V
    c) 0.2 V

Answer 80

b) 0.12 V

Question 81

81. An electrolytic capacitor is used where
    a) minimum losses are essential
    b) there is a polarized input
    c) high frequency AC is used

Answer 81

b) there is a polarized input

Question 82

82. If a connection to an AC motor is disconnected, the motor will
    a) slow down and stop
    b) continue to run
    c) stop

Answer 82

b) continue to run

Question 83

83. A band stop filter
    a) stops a narrow range of frequencies
    b) stops frequencies either side of a narrow range
    c) attenuates frequencies either side of a narrow range

Answer 83

a) stops a narrow range of frequencies

Question 84

84. This is a diagram of a
    a) band pass filter
    b) high pass filter
    c) low pass filter

Answer 84

c) low pass filter

Question 85

85. When comparing the average values of an AC generator output, to the peak values
    a) average voltage = same as the peak voltage
    b) average voltage = 0.63 x peak voltage
    c) average voltage = 0.707 x peak voltage

Answer 85

b) average voltage = 0.63 x peak voltage

Question 86

86. A parallel circuit at resonance has
    a) maximum impedance
    b) minimum impedance
    c) zero impedance

Answer 86

a) maximum impedance

Question 87

87. A resistor dissipates 80 Watts. If it runs for 4 hours 15 minutes, how much energy is dissipated in total?
    a) 1.224 MJ
    b) 20.4 kJ
    c) 191.25 J

Answer 87

a) 1.224 MJ

Question 88

88. The earth lead of a 24 V equipment is 0.5 ohm resistance and carries 80 A. How much power does it dissipate?
    a) 3.2 kW
    b) 1.152 kW
    c) 1.92 kW

Answer 88

a) 3.2 kW

Question 89

89. What must you do to make a 3 F capacitor circuit into a 2 F circuit?
    a) Put a 1 F capacitor in series
    b) Put a 2 F capacitor in parallel
    c) Put a 6 F capacitor in series

Answer 89

c) Put a 6 F capacitor in series

Question 90

90. The time required to fully charge a 1 µF capacitor in series with a 100k ohm resistor is
    a) 100 ms
    b) 1 s
    c) 100 s

Answer 90

a) 100 ms

Question 91

91. A 10 ohm resistor has a 14.14 V peak drop across it. What power is dissipated?
    a) 19.99 W
    b) 10 W
    c) 1.414 W

Answer 91

b) 10 W

Question 92

92. This is a symbol for
    a) a voltage dependent resistor
    b) a variable differential resistor
    c) a visual display rectifier

Answer 92

a) a voltage dependent resistor

Question 93

93. If a generator speed is halved and the field strength is doubled, the voltage output will be
    a) halved
    b) doubled
    c) unchanged

Answer 93

c) unchanged

Question 94

94. Point A on the armature of the generator shown is producing
    a) maximum current
    b) minimum current
    c) zero current

Answer 94

a) maximum current

Question 95

95. An accumulation of hydrogen on the plates of a battery is known as
    a) hydration
    b) polarization
    c) ionization

Answer 95

b) polarization

Question 96

96. What is the power dissipated in a 500 ohm resistor with a 3A flow?
    a) 1.5 kW
    b) 4.5 kW
    c) 750 kW

Answer 96

b) 4.5 kW

Question 97

97. Which of the following is 1 Amp?
    a) 1000 mA
    b) 1000 μA
    c) 1000 kA

Answer 97

a) 1000 mA

Question 98

98. A paramagnetic material has a relative permeability of
    a) greater than unity
    b) less than unity
    c) zero

Answer 98

a) greater than unity

Question 99

99. What part of a battery is covered in hydrogen during polarization?
    a) Cathode
    b) Anode
    c) Both the anode and the cathode

Answer 99

a) Cathode

Question 100

100. Electricity conducts through
     a) solids only
     b) solids and liquids
     c) vacuum

Answer 100

b) solids and liquids

Question 101

101. The term that describes the combined resistive forces in an AC circuit is
     a) impedance
     b) resistance
     c) total resistance

Answer 101

a) impedance

Question 102

102. How can the direction of rotation of a DC electric motor be changed
     a) reverse the electrical connections to either the field or armature windings
     b) interchange the wires which connect the motor to the external power source
     c) rotate the positive brush one commutator segment

Answer 102

a) reverse the electrical connections to either the field or armature windings

Question 103

103. An example of a good electrical insulator is
     a) glass
     b) aluminium
     c) mercury

Answer 103

a) glass

Question 104

104. The only practical method of maintaining a constant voltage output from an aircraft generator under varying conditions of speed and load is to vary the
     a) strength of the magnetic field
     b) number of conductors in the armature
     c) speed at which the armature rotates

Answer 104

a) strength of the magnetic field

Question 105

105. An accumulation of hydrogen on the plates of a battery is known as
     a) hydration
     b) polarization
     c) ionization

Answer 105

b) polarization

Question 106

106. Which of the following is most likely to cause thermal runaway in a nickel-cadmium battery
     a) excessive current draw from the battery
     b) high current charging of the battery to more than 100 percent of its capacity
     c) a high internal resistance condition

Answer 106

b) high current charging of the battery to more than 100 percent of its capacity

Question 107

107. Electric motors are often classified according to the method of connecting the field coils and armature. Aircraft engine starter motors are generally of which type
     a) compound
     b) shunt (parallel)
     c) series

Answer 107

c) series

Question 108

108. If a heavy mechanical load is removed from a series motor
     a) the speed will decrease and the armature current will decrease
     b) the speed will increase and the armature current will decrease
     c) the speed will increase and the armature current will increase

Answer 108

b) the speed will increase and the armature current will decrease

Question 109

109. Static charges remaining in an aircraft are dissipated by
     a) the use of a conducting type nose wheel
     b) bonding the aircraft to a refuel tanker
     c) earthing the aircraft as soon as possible

Answer 109

a) the use of a conducting type nose wheel

Question 110

110. Total resistance in parallel for R1 and R2 is
     a) RT = (R1 x R2) ÷ (R1 + R2)
     b) RT = 1/R1 + 1/R2
     c) 1/RT = 1/R1 + 1/R2

Answer 110

a) RT = (R1 x R2) ÷ (R1 + R2)

Question 111

111. The quill drive on an aircraft generator
     a) makes possible the use of roller
     b) damps out any commutator ripple
     c) damps out vibrations

Answer 111

c) damps out vibrations

Question 112

112. The method of ascertaining the voltage of a standard aircraft lead-acid battery is by checking
     a) the voltage on open circuit
     b) the voltage with rated load switched ON
     c) the voltage off load

Answer 112

b) the voltage with rated load switched ON

Question 113

113. If the correct supply were connected to a DC shunt motor which had lost its residual magnetism it would
     a) fail to run
     b) run in the reverse direction
     c) run normally

Answer 113

c) run normally

Question 114

114. A loss of electrical insulation results in
     a) a short circuit between the supply and earth
     b) an open circuit between the supply and earth
     c) an open circuit in the supply

Answer 114

a) a short circuit between the supply and earth

Question 115

115. A DC circuit containing a total resistance of 100 ohms has a current flow of 250 mA. The power dissipated in the circuit is
     a) 0.4 watts
     b) 6.25 watts
     c) 5 watts

Answer 115

b) 6.25 watts

Question 116

116. Power is the rate of doing work. It is measured in
     a) joules/second
     b) watts/second
     c) joules x seconds

Answer 116

a) joules/second

Question 117

117. Ohm’s law states that:
     a) e.m.f. = current divided by resistance
     b) resistance = current divided by e.m.f.
     c) current = e.m.f. divided by resistance

Answer 117

c) current = e.m.f. divided by resistance

Question 118

118. If the resistance of a resistor which is in series with two other resistors is doubled
     a) the current in that resistance is doubled
     b) the current in that resistance is halved
     c) the volts drop across that resistor increases

Answer 118

c) the volts drop across that resistor increases

Question 119

119. One purpose of a growler test is to determine the presence of:
     a) a shorted armature
     b) an out-of-round commutator
     c) a broken field lead

Answer 119

a) a shorted armature

Question 120

120. Through which material will magnetic lines of force pass the most readily?
     a) aluminium
     b) iron
     c) copper

Answer 120

b) iron

Question 121

121. Electricity conducts through
     a) solids only
     b) solids and liquids
     c) vacuum

Answer 121

b) solids and liquids

Question 122

122. The secondary coil of a transformer has 1500 turns and 10 Ω resistance. The primary coil has 1 k Ω resistance. How many turns does the primary coil have?
     a) 15,000
     b) 150,000
     c) 1,500,000

Answer 122

a) 15,000

Question 123

123. Two batteries 12V and 40 Ah each, are in series. What is the total capacity?
     a) 12V 80 Ah
     b) 24V 80Ah
     c) 24V 40 Ah

Answer 123

c) 24V 40 Ah

Question 124

124. In a star wound primary transformer, how could you wind the secondary winding?
     a) star only
     b) delta only
     c) either delta or star

Answer 124

c) either delta or star

Question 125

125. The phases in supply to a 2 phase motor are electrically
     a) 90 degrees apart from each other
     b) 180 degrees apart from each other
     c) 120 degrees apart from each other

Answer 125

a) 90 degrees apart from each other

Question 126

126. A 30 KVA rated generator has a power factor of 0.8. What is its maximum consistent power
     a) 30 KW
     b) 24 KW
     c) 37.5 KW

Answer 126

b) 24 KW

Question 127

127. A 50 μF capacitor is fed with a current of 25 mA. How long will it take to charge it to 100V?
     a) 1 s
     b) 0.2 seconds
     c) 12 minutes

Answer 127

b) 0.2 seconds

Question 128

128. The total resistance of the circuit shown is
     a) 1.33 Ohms
     b) 12 Ohms
     c) 3 Ohms

Answer 128

c) 3 Ohms

Question 129

129. A step up transformer has
     a) one winding
     b) two windings
     c) three windings

Answer 129

b) two windings

Question 130

130. The three voltages of a three phase generator are connected
     a) independently of each other
     b) in series with each other
     c) in parallel with each other

Answer 130

a) independently of each other

Question 131

131. E.M.F. in an electric circuit corresponds to what in a magnetic circuit
     a) mmf
     b) flux
     c) reluctance

Answer 131

a) mmf

Question 132

132. Time constant of an inductor is
     a) LR
     b) L/R
     c) L^2/R

Answer 132

b) L/R

Question 133

133. Permanent magnets have
     a) high reluctance, low coercive force
     b) low reluctance, high coercive force
     c) high reluctance, high coercive force

Answer 133

c) high reluctance, high coercive force

Question 134

134. A.C. value that can produce the same heat as D.C. is called
     a) r.m.s value
     b) average value
     c) peak value

Answer 134

a) r.m.s value

Question 135

135. If a battery has got low internal resistance, then
     a) on load voltage will be greater than no load voltage
     b) no load voltage will be greater than on load voltage
     c) no load voltage will be the same as on load voltage

Answer 135

b) no load voltage will be greater than on load voltage

Question 136

136. in a parallel R, L, C circuit, the value of the capacitor is quadrupled, then the value of the impedance would
     a) reduce
     b) increased
     c) remain the same

Answer 136

a) reduce

Question 137

137. In a circuit C = 25 microfarads and the current flow is
     40 microamps for 4 seconds. What is the voltage
     a) 12.8V
     b) 6.4V
     c) 3.2V

Answer 137

b) 6.4V

Question 138

138. A 3, 5 and 2 ohms resistance is connected in series with a 10 V battery. The voltage across the 2 ohms resistor is
     a) 10V
     b) 2 V
     c) 4 V

Answer 138

b) 2 V

Question 139

139. The power in a circuit when voltage and resistance is given can be found by
     a) VxR
     b) VxV / R
     c) VxVxR

Answer 139

b) VxV / R

Question 140

140. A piezoelectric device generates electricity through
     a) pressure
     b) friction
     c) light

Answer 140

a) pressure

Question 141

141. Conventional current flow inside a battery is from
     a) anode to cathode
     b) cathode to anode
     c) either anode to cathode or cathode to anode, depending on the active elements

Answer 141

a) anode to cathode

Question 142

142. Potentiometers are used as a
     a) variable voltage source
     b) variable resistor
     c) variable current source

Answer 142

a) variable voltage source

Question 143

143. In a transformer core loss is 200 W and copper loss
     is 220W at no load. What is the core loss at full load
     a) 200 W
     b) 220 W
     c) 0 W

Answer 143

a) 200 W

Question 144

144. Calculate the speed of a 400 Hz, 4 pole machine
     a) 12,000 rpm
     b) 6000 rpm
     c) 8000 rpm

Answer 144

a) 12,000 rpm

Question 145

145. The purpose of end travel microswitch in a linear actuator is to
     a) remain closed and opens at end travel only
     b) remain open and closes at end travel only
     c) remain open during normal operation and only close if the actuator overruns its stops

Answer 145

a) remain closed and opens at end travel only

Question 146

146. Linear actuators used in aircraft are of
     a) split field series wound type.
     b) split field shunt wound type
     c) compound wound type

Answer 146

a) split field series wound type.

Question 147

147. If a generator sparks, a possible reason is
     a) The brush springs are loose
     b) The brushes have been placed around the magnetic coil
     c) Magnetic flux deflecting the EMF

Answer 147

a) The brush springs are loose

Question 148

148. The charge on a proton is
     a) neutral
     b) positive
     c) negative

Answer 148

b) positive

Question 149

149. in conventional current flow, what is Fleming’s right hand rule used for
     a) Motors
     b) Generators
     c) Inductors

Answer 149

b) Generators

Question 150

150. In a capacitive circuit, if the frequency is increased
     a) the current increases
     b) impedance increases
     c) reactance remains the same

Answer 150

a) the current increases

Question 151

151. Three 12 µF capacitors are in series. The total capacitance is
     a) 12 µF
     b) 4 µF
     c) 36 µF

Answer 151

b) 4 µF

Question 152

152. A 500 ohm resistor carries a 3 amp current. What is the power dissipated?
     a) 5 kW
     b) 4.5 kW
     c) 500 W

Answer 152

b) 4.5 kW

Question 153

153. A paramagnetic material has a relative permeability
     a) less than unity
     b) greater than unity
     c) equal to unity

Answer 153

b) greater than unity

Question 154

154. What is the PD of a circuit which has a 40 mA current and a 1 k ohm resistance?
     a) 400 V
     b) 4 V
     c) 40 V

Answer 154

c) 40 V

Question 155

155. The time constant of a capacitor is the time
     a) for the emf to reach 36.8% of maximum
     b) the current to reach 70.7% of maximum
     c) to reach maximum current

Answer 155

a) for the emf to reach 36.8% of maximum

Note: 36.8% is the TC for discharge, while charging one TC = 63.2%

Question 156

156. The secondary winding of a transformer has an impedance of 10 ohms and 1500 turns. For the primary winding to have an impedance of 1 k ohm, how many
     turns must it have?
     a) 15,000
     b) 150,000
     c) 1,500,000

Answer 156

a) 15,000

Question 157

157. A potentiometer has which of the following properties?
     a) 3 terminals
     b) preset values
     c) wire wound

Answer 157

a) 3 terminals

Question 158

158. A 3 ohm resistor dissipates 27 Watts. How much current flows through it?
     a) 3 A
     b) 9 A
     c) 0.15 A

Answer 158

a) 3 A

Question 159

159. in a 2 phase generator, how far apart are the windings electrically?
     a) 45^
     b) 90^
     c) 180^

Answer 159

b) 90^

Question 160

160. The SI unit of work is
     a) Joules per second (Watts)
     b) Kilogram metres - force
     c) Joules per metre

Answer 160

b) Kilogram metres - force

Question 161

161. in the circuit below, what happens to the total circuit impedance if L is tripled?
     a) Increases
     b) Remains the same
     c) Reduces

Answer 161

a) Increases

Question 162

162. in a voltaic cell, what is the build-up on the cathode called?
     a) Polarization
     b) Sulphation
     c) Hydration

Answer 162

a) Polarization

Question 163

163. A sine wave has a periodic time of 0.5 milliseconds. What is the frequency
     a) 200 Hz
     b) 2 kHz
     c) 20 kHz

Answer 163

b) 2 kHz

Question 164

164. Three branches in a circuit have currents entering of 3A, 4 A and 5 A. A forth branch has 10 A leaving. A fifth branch must have
     a) 2A entering
     b) 2A leaving
     c) 22A leaving

Answer 164

b) 2A leaving

Question 165

165. Where are the output windings on an AC generator?
     a) Stator
     b) Rotor with slip rings
     c) Rotor with commutator

Answer 165

a) Stator

Question 166

166. If the field strength of a generator is doubled, and the speed is doubled, the output EMF will
     a) quadruple
     b) double
     c) stay the same

Answer 166

a) quadruple

Question 167

167. If the rate of change of current is halved, mutual inductance will
     a) double
     b) stay the same
     c) half

Answer 167

b) stay the same

Question 168

168. If a capacitor of 50 microfarads has a current of 25 mA, how long does it take to charge to 100 V
     a) 200 milliseconds
     b) 200 seconds
     c) 150 seconds

Answer 168

a) 200 milliseconds

Question 169

169. in a Wheatstone Bridge, the ammeter reads zero, and the variable resistor is adjusted to 5 ohms. Resistor P has a value of 10 ohms and Q has a value of 100 ohms. What is the value of the unknown resistor?
     a) 0.5 ohms
     b) 5 ohms
     c) 50 ohms

Answer 169

c) 50 ohms

Question 170

170. in a tuned circuit at resonance, the circuit will be
     a) inductive
     b) resistive
     c) capacitive

Answer 170

b) resistive

Question 171

171. The time constant for an inductor is
     a) L/R
     b) R/L
     c) L x R

Answer 171

a) L/R

Question 172

172. In a DC motor the pole pairs are
     a) imbedded within the field coils
     b) part of the armature
     c) connected to the brush gear

Answer 172

a) imbedded within the field coils

Question 173

173. Eddy currents in a transformer core are reduced by
     a) decreasing the thickness of the laminates
     b) increasing the thickness of the laminates
     c) making the core from a solid block

Answer 173

a) decreasing the thickness of the laminates

Question 174

174. Transformer copper loss on full load is 220 Watts. On half load the loss will be
     a) 110 Watts
     b) 440 Watts
     c) 55 Watts

Answer 174

c) 55 Watts

Question 175

175. The earth’s magnetic field is greatest at the
     a) magnetic poles
     b) geographic poles
     c) magnetic equator

Answer 175

a) magnetic poles

Question 176

176. If a 1 ohm circuit produces a 50 W output, the phase
     angle is
     a) 0^
     b) 90^
     c) 45^

Answer 176

a) 0^

Question 177

177. A series wound DC motor, the field has
     a) few turns of thick wire
     b) few turns of thin wire
     c) many turns of thin wire

Answer 177

a) few turns of thick wire

Question 178

178. What effect do the electrons of one atom have upon the electrons of another atom?
     a) They repel each other
     b) They attract each other
     c) They have no effect on each other

Answer 178

a) They repel each other

Question 179

179. What is a molecule?
     a) The smallest part of a compound
     b) The smallest part of an electron
     c) The smallest part of an atom

Answer 179

a) The smallest part of a compound

Question 180

180. A coulomb is
     a) one ampere per second
     b) one ampere x second
     c) one second per ampere

Answer 180

b) one ampere x second

Question 181

181. in a circuit containing three resistors of equal value connected in parallel, one resistor goes open circuit. The current in the other two resistors will
     a) increase
     b) decrease
     c) remain the same

Answer 181

c) remain the same

Question 182

182. 20 amperes flow for 20 seconds. How many coulombs has flowed?
     a) 400
     b) 20
     c) 1

Answer 182

a) 400

Question 183

183. An atom is
     a) the smallest part of an element that retains its characteristics
     b) the smallest part of a compound that can exist independently
     c) the smallest particle of matter

Answer 183

a) the smallest part of an element that retains its characteristics

Question 184

184. A neutron is a particle which is
     a) contained within the nucleus of most atoms
     b) orbits the nucleus of the atom
     c) contained in the nucleus of all atoms

Answer 184

a) contained within the nucleus of most atoms

Question 185

185. An electric current is a flow of
     a) electrons from a positively charged area to a negatively charged area
     b) protons from a positively charged area to a negatively charged area
     c) electrons from a negatively charged area to a positively charged area

Answer 185

c) electrons from a negatively charged area to a positively charged area

Question 186

186. An element could be considered to be a conductor if it has
     a) a large number of electrons
     b) a large number of electrons in its outer orbit
     c) a small number of electrons in its outer orbit

Answer 186

c) a small number of electrons in its outer orbit

Question 187

187. A volt can be considered to be a
     a) unit of electrical pressure
     b) quantity of electrical energy
     c) unit of electrical power

Answer 187

a) unit of electrical pressure

Question 188

188. If the resistance of an electrical circuit is increased
     a) the voltage will increase
     b) the current will increase
     c) the current will decrease

Answer 188

c) the current will decrease

Question 189

189. If 2 coulombs flowed through a circuit in 2 seconds, the circuit would have
     a) 2 volts PD
     b) 2 amps
     c) 1 amp

Answer 189

c) 1 amp

Question 190

190. In general, increasing the cross sectional area of an electrical cable
     a) enables it to carry more current
     b) enables it to carry more voltage
     c) increases its resistance

Answer 190

a) enables it to carry more current

Question 191

191. Doubling the running time of an electrical machine would
     a) double the joules used
     b) double the watts used
     c) double the current used

Answer 191

a) double the joules used

Question 192

192. What is 3.25 volts in millivolts
     a) 3.25 millivolts
     b) 3,250 millivolts
     c) 325,000 millivolts

Answer 192

b) 3,250 millivolts

Question 193

193. Electromotive force is measured in
     a) Watts
     b) Ohms
     c) Volts

Answer 193

c) Volts

Question 194

194. Six resistors each of 6 ohms would be
     a) 36 ohms in parallel
     b) 1 ohm in series
     c) 1 ohm in parallel

Answer 194

c) 1 ohm in parallel

Question 195

195. A capacitor in a single phase motor is to
     a) provide a phase shift
     b) prevent sparking at the switch
     c) provide smoothing

Answer 195

a) provide a phase shift

Question 196

196. The mass of an atom is contained mainly in the
     a) electron
     b) nucleus
     c) proton

Answer 196

b) nucleus

Question 197

197. The line voltage from a generator with a delta type connection will be
     a) higher than the phase voltage
     b) lower than the phase voltage
     c) the same as the phase voltage

Answer 197

c) the same as the phase voltage

Question 198

198. On a linear actuator, the field cutoff coil will be energized when
     a) the actuator is running
     b) the actuator is not running
     c) only as the actuator commences movement

Answer 198

a) the actuator is running

Question 199

199. Kirchhoff’s law states
     a) the algebraic sum of all the voltages entering or leaving a series of components will be equal to zero
     b) the algebraic sum of all the currents entering or leaving a series of components will be equal to one
     c) the inverse sum of all the voltages entering or leaving a series of components will be equal to one

Answer 199

a) the algebraic sum of all the voltages entering or leaving a series of components will be equal to zero

Question 200

200. The lines of magnetic flux from a magnet will
     a) repel each other
     b) attract each other
     c) have no effect upon each other

Answer 200

a) repel each other

Question 201

201. A photozoidal cell produces electricity when subjected to
     a) light
     b) heat
     c) pressure

Answer 201

a) light

Question 202

202. A thermocouple indicator is basically a type of
     a) milliammeter
     b) millivoltmeter
     c) milliohmeter

Answer 202

b) millivoltmeter

Question 203

203. An electric motor produces a force of 5 N at a distance of 0.2m from the centre of rotation and rotates at a speed of 100 revs/sec. The motors output is
     a) 100 horsepower
     b) 628.4 watts
     c) 314.2 watts

Answer 203

b) 628.4 watts

Question 204

204. A potentiometer varies
     a) voltage
     b) current
     c) resistance

Answer 204

a) voltage

Question 205

205. Starter motors are usually
     a) series wound
     b) compound wound
     c) shunt wound

Answer 205

a) series wound

Question 206

206. How can it be determined if a transformer winding has some of its turns shorted together?
     a) measure the input voltage with an ohmmeter
     b) the transformer will get hot in normal operation
     c) the output voltage will be high

Answer 206

b) the transformer will get hot in normal operation

Question 207

207. An advantage of a star connected generator over a delta connected generator is
     a) a balance load is guaranteed
     b) two potentials are available
     c) the line and phase voltages are equal

Answer 207

b) two potentials are available

Question 208

208. What does a rectifier do?
     a) Changes direct current into alternating current
     b) Changes alternating current into direct current
     c) Reduces voltage

Answer 208

b) Changes alternating current into direct current

Question 209

209. Two 12V 40 amp hour batteries connected in parallel will produce
     a) 24V 80 ah
     b) 12V 80 ah
     c) 24V 40 ah

Answer 209

b) 12V 80 ah

Question 210

210. When an atom loses or gains an electron it is called
     a) a current
     b) an ion
     c) a molecule

Answer 210

b) an ion

Question 211

211. A circuit has a resistance of 50 ohms and an inductance of 0.2 Henry. If it is connected to a 200 volt 50 Hz supply the reactance will be
     a) 31.42 ohms
     b) 62.84 ohms
     c) 6.284 ohms

Answer 211

b) 62.84 ohms

Question 212

212. A 24-volt source is required to furnish 48 watts to a parallel circuit consisting of four resistors of equal value. What is the voltage drop across each resistor?
     a) 12 volts
     b) 24 volts
     c) 3 volts

Answer 212

b) 24 volts

Question 213

213. Of the following which pair of materials would most readily become magnetized?
     a) copper and steel
     b) nickel and bronze
     c) iron and steel

Answer 213

c) iron and steel

Question 214

214. The formula for resistance in series is
     a) RT = R1 + R2 + R3…RN
     b) RT = R1 x R2 x R3…RN
     c) 1/RT = 1/ (R1 x R2 x R3 …RN)

Answer 214

a) RT = R1 + R2 + R3…RN

Question 215

215. The core material used for an electromagnet is soft iron because
     a) it demagnetizes easily
     b) its magnetism is not easily destroyed
     c) it retains most of its flux density when demagnetized

Answer 215

a) it demagnetizes easily

Question 216

216. What is the combined value of resistances of 4 ohm and 6 ohm connected in parallel?
     a) 24 ohm
     b) 2.4 ohm
     c) 0.24 ohm

Answer 216

b) 2.4 ohm

Question 217

217. Permanent magnets in an AC generator are
     a) to provide initial excitation
     b) to control the frequency
     c) to rectify the current

Answer 217

a) to provide initial excitation

Question 218

218. The method of ascertaining the voltage of a standard aircraft lead-acid battery is by checking
     a) the voltage off load
     b) the voltage on open circuit
     c) the voltage with rated load switched ON.

Answer 218

c) the voltage with rated load switched ON.

Question 219

219. Generator brushes are normally made of
     a) carbon
     b) brass
     c) steel

Answer 219

a) carbon

Question 220

220. If the voltage across a resistor is doubled
     a) the current is doubled
     b) the resistance is halved
     c) the current is halved

Answer 220

a) the current is doubled

Question 221

221. As the generator load is increases (within its rated capacity), the voltage will
     a) remain constant and the amperage output will decrease
     b) decrease and the amperage output will increase
     c) remain constant and the amperage output will increase

Answer 221

c) remain constant and the amperage output will increase

Question 222

222. If a number of resistors are connected in parallel, the total resistance is
     a) the same as the lowest
     b) smaller than the lowest
     c) greater than the lowest

Answer 222

b) smaller than the lowest

Question 223

223. A charged body is said to have
     a) a surplus or deficiency of electrons
     b) a surplus of protons
     c) a deficiency of neutrons

Answer 223

a) a surplus or deficiency of electrons

Question 224

224. The ratio between apparent power and true power is the
     a) efficiency
     b) power rating
     c) power factor

Answer 224

c) power factor

Question 225

225. The voltage output of a generator is controlled by
     a) varying the current of the output
     b) varying the resistance of the output
     c) varying the current of the field

Answer 225

c) varying the current of the field

Question 226

226. The total current flowing in a circuit of 200 lamps in parallel, each of a resistance of 400 ohm and connected across an input of 100 volts is
     a) 50 amps
     b) 25 amps
     c) 40 amps

Answer 226

a) 50 amps

Question 227

227. The current flowing in the armature of a DC motor is equal to
     a) (applied volts - generated volts) x armature resistance
     b) (applied volts + generated volts) / armature resistance
     c) (applied volts - generated volts) / armature resistance

Answer 227

c) (applied volts - generated volts) / armature resistance

Question 228

228. In the circuit shown the 24 volt battery has an internal resistance of 1 ohm and the ammeter indicates a current of 12 amperes. The value of the load resistance is
     a) 1 ohm
     b) 2 ohms
     c) 6 ohms

Answer 228

a) 1 ohm

Question 229

229. One advantage of using Ac electrical power in aircraft is
     a) the greater ease in stepping the voltage up or down
     b) AC electrical motors can be reversed while dc motors cannot
     c) the effective voltage is 1.41 times the maximum instantaneous voltage; less power input is required

Answer 229

a) the greater ease in stepping the voltage up or down

Question 230

230. The quill drive on an aircraft generator
     a) makes possible the use of roller bearings at the drive end
     b) damps out vibrations
     c) damps out any commutator ripple

Answer 230

b) damps out vibrations

Question 231

231. The amount of electricity a capacitor can store is
     directly proportional to the
     a) distance between the plates and inversely proportional to the plate area
     b) plate area and is not affected by the distance between the plates
     c) plate area and inversely proportional to the distance between the plates

Answer 231

c) plate area and inversely proportional to the distance between the plates

Question 232

232. When resistors are in parallel, the total resistance is
     a) smaller than the smallest resistor
     b) the sum of all the resistors
     c) larger than the smallest resistor

Answer 232

a) smaller than the smallest resistor

Question 233

233. What device is used to convert alternating current, which has been induced into the loops of the rotating armature of a DC generator into direct current as it leaves
     the generator?
     a) a commutator
     b) an inverter
     c) a rectifier

Answer 233

a) a commutator

Question 234

234. Two similar 12v batteries connected in parallel will produce
     a) 24V e.m.f. with twice the capacity of each battery
     b) 24v e.m.f. with the same capacity as each battery
     c) 12V e.m.f. with twice the capacity of each battery

Answer 234

c) 12V e.m.f. with twice the capacity of each battery

Question 235

235. Unless otherwise specified, any values given for current or voltage in an AC circuit are assumed to be
     a) maximum values
     b) effective values
     c) instantaneous values

Answer 235

b) effective values

Question 236

236. If a heavy mechanical load is removed from a series
     motor
     a) the speed will increase and the armature current will decrease
     b) the speed will decrease and the armature current will decrease
     c) the speed will increase and the armature current will increase

Answer 236

a) the speed will increase and the armature current will decrease

Question 237

237. In a vector diagram showing the magnitude and direction of the inductance, capacitance and resistance in an AC circuit
     a) the inductive reactance would be in opposition tothe capacitive reactance and resistance at 90 degrees
     b) the inductive and capacitance reactance would be additive with the resistance subtractive
     c) it is impossible to show values of this kind using vectors

Answer 237

a) the inductive reactance would be in opposition tothe capacitive reactance and resistance at 90 degrees

Question 238

238. If service No. 1 is isolated from the supply busbar shown there will be
     a) an increase in supply voltage
     b) a decrease in supply voltage
     c) a decrease in total current consumption

Answer 238

c) a decrease in total current consumption

Question 239

239. An increase in operating temperature in most electrical devices carrying current results in
     a) an increase in resistance and a decrease in current
     b) a decrease in resistance and an increase in current
     c) no effect on the resistance and current

Answer 239

a) an increase in resistance and a decrease in current

Question 240

240. The voltage of a secondary cell is
     a) determined by the number of plates
     b) determined by the area of the plates
     c) determined by the active materials on the plates

Answer 240

c) determined by the active materials on the plates

Question 241

241. The basis for transformer operation in the use of alternating current is mutual
     a) reactance
     b) inductance
     c) capacitance

Answer 241

b) inductance

Question 242

242. The exciter winding in a brushless AC generator is supplied with electrical power from
     a) permanent magnets
     b) the busbar
     c) a rotating generator integrally mounted on the same shaft as the AC windings

Answer 242

c) a rotating generator integrally mounted on the same shaft as the AC windings

Question 243

243. If the cross-sectional area of a conductor is doubled, with voltage constant, the current will
     a) halve
     b) double
     c) remain constant

Answer 243

b) double

Question 244

244. Eddy currents in a transformer can be reduced by
     a) using a special non metallic material
     b) using a single solid piece of metal
     c) laminations

Answer 244

c) laminations

Question 245

245. If two resistors of 5 and 10 ohm respectively are connected in series and the current in the 5 ohm resistor is 1A. what is the current in the 10 ohm resistor?
     a) 1/3 amp
     b) it cannot be found without knowing the applied voltage
     c) 1 amp

Answer 245

c) 1 amp

Question 246

246. The term used to denote the strength of a magnetic field is
     a) retentivity
     b) hysterisis
     c) flux density

Answer 246

c) flux density

Question 247

247. At resonant frequency the phase difference between the voltage and current of an AC supply feeding an inductive and capacitive network is
     a) 0 degrees
     b) 180 degrees
     c) 90 degrees

Answer 247

a) 0 degrees

Question 248

248. What is the ratio of turns between the primary coil winding and the secondary coil winding of a transformer designed to triple its input voltage?
     a) primary will have three times as many turns as its secondary
     b) primary will have twice as many turns as its secondary
     c) primary will have one-third as many turns as its secondary

Answer 248

c) primary will have one-third as many turns as its
secondary

Question 249

249. A direct current of 12 milliamperes flows through a circuit which has a resistance of 1000 ohms. The power dissipated by the circuit is
     a) 12 milliwatts
     b) 12 watts
     c) 144 milliwatts

Answer 249

c) 144 milliwatts

Question 250

250. The voltage in a series circuit
     a) is different in each component
     b) is the same in each component
     c) is less than it would be in a parallel circuit

Answer 250

a) is different in each component

Question 251

251. Which aircraft circuit would be most likely to use frequency wild 200V AC?
     a) windscreen heating
     b) hydraulic pump
     c) standby compass

Answer 251

a) windscreen heating

Question 252

252. Why are the iron cores of most induction coils laminated?
     a) To reduce the effects of eddy currents
     b) To increase the core permeability
     c) To reduce the core reluctance

Answer 252

a) To reduce the effects of eddy currents

Question 253

253. A 48-volt source is required to furnish 192 watts to a parallel circuit consisting of three resistors of equal value. What is the value of each resistor?
     a) 12 ohm
     b) 4 ohm
     c) 36 ohm

Answer 253

c) 36 ohm

Question 254

254. If voltage is 100V, resistance is 25 ohms, what is the current?
     a) 2500 amperes
     b) 4 amperes
     c) 0.4 amperes

Answer 254

b) 4 amperes

Question 255

255. A soft iron core is used in an ELECTRO magnet because
     a) it has HIGH permeability and HIGH coercivity
     b) it has HIGH permeability and LOW coercivity
     c) it has LOW permeability and HIGH coercivity

Answer 255

b) it has HIGH permeability and LOW coercivity

Question 256

256. The resistance to electrical flow in a wire depends on
     a) the diameter, length, material of wire and temperature
     b) the material only - copper or aluminum
     c) the length and material of the wire only

Answer 256

a) the diameter, length, material of wire and temperature

Question 257

257. A transformer should always have its
     a) secondary open circuit or on load
     b) secondary shorted or on load
     c) primary shorted or off load

Answer 257

a) secondary open circuit or on load

Question 258

258. How can the direction of rotation of a DC electric motor be changed?
     a) interchange the wires which connect the motor to the external power source
     b) reverse the electrical connections to either the field or armature windings
     c) rotate the positive brush one commutator segment

Answer 258

b) reverse the electrical connections to either the field or armature windings

Question 259

259. An AC generator’s frequency will
     a) always be constant regardless of the generators
     drive speed
     b) vary with changes in field strength
     c) be proportional to the RPM at which it is driven

Answer 259

c) be proportional to the RPM at which it is driven

Question 260

260. A short circuit between the supply and earth
     a) does not matter if the circuit uses the aircraft earth as a return
     b) could be very dangerous as the current drawn will be very high
     c) is not dangerous as the current drawn will be low

Answer 260

b) could be very dangerous as the current drawn will be very high

Question 261

261. When two coils are linked by a common flux, a voltage can be induced in one by a changing current in the other. This process is known as
     a) mutual induction
     b) the magnetic effect
     c) self induction

Answer 261

a) mutual induction

Question 262

262. A circuit consists of 3 ohm, 5 ohm and 12 ohm resistors in series, the current flowing in the 5 ohm resistor is 10 amps. What is the applied voltage?
     a) 100v
     b) 10v
     c) 200v

Answer 262

c) 200v

Question 263

263. Copper is an inferior conductor to aluminum when comparing
     a) weight for weight
     b) load for load
     c) CSA with CSA

Answer 263

a) weight for weight

Question 264

264. In an AC circuit how is the value of true power calculated?
     a) By volts multiplied by amps multiplied by power factor
     b) By wattmeter readings multiplied by power factor
     c) By voltmeter readings multiplied by ammeter readings

Answer 264

a) By volts multiplied by amps multiplied by power factor

Question 265

265. A frequency wild AC generator is used for
     a) instruments and navigation
     b) de-icing loads
     c) any AC load

Answer 265

b) de-icing loads

Question 266

266. Which of the following is not one of the purposes of interpoles in a generator?
     a) Reduce field strength
     b) Overcome armature reaction
     c) Reduce arcing at the brushes

Answer 266

a) Reduce field strength

Question 267

267. Which of the following would be used to calculate transformer turns ratio?
     a) primary turns × secondary turns
     b) primary turns ÷ secondary turns
     c) secondary turns ÷ primary turns

Answer 267

c) secondary turns ÷ primary turns

Question 268

268. A good electrical insulator is a material which
     a) has more protons than electrons
     b) has its electrons tightly bound to their parent atoms
     c) contains a large number of positive ions

Answer 268

b) has its electrons tightly bound to their parent atoms

Question 269

269. To reverse the direction of a series motor
     a) the direction of the current through the field is reversed
     b) a second series field is fitted
     c) the direction of the current through the field and the armature is reversed

Answer 269

b) a second series field is fitted

Question 270

270. How many cycles of AC voltage are produced in a six-pole alternator of the revolving-field type, with each revolution of the rotor?
     a) Four
     b) Six
     c) Three

Answer 270

c) Three

Question 271

271. The variable frequency output from an AC generator is used for
     a) supplying non-inductive loads
     b) the AC supply instead of using inverters
     c) driving AC operated instruments

Answer 271

a) supplying non-inductive loads

Question 272

272. The capacitance of a capacitor is dependent upon
     a) the type of material separating the plates
     b) the rate of change of current in the circuit
     c) the charge on it

Answer 272

a) the type of material separating the plates

Question 273

273. A piece of equipment is rated at 750 watts and the applied voltage is 30 volts. The value of the protection fuse should be
     a) 20 amps
     b) 30 amps
     c) 15 amps

Answer 273

b) 30 amps

Question 274

274. The current consumed by a DC starter motor will
     a) remain relatively constant over the starting speed range
     b) increase as the engine speed increases
     c) decrease as the engine speed increases

Answer 274

c) decrease as the engine speed increases

Question 275

275. When different rated capacitors are connected in parallel in a circuit, the total capacitance is
     a) equal to the capacitance of the highest rated capacitor
     b) less than the capacitance of the lowest rated capacitor
     c) equal to the sum of all the capacitances

Answer 275

c) equal to the sum of all the capacitances

Question 276

276. The voltage in a transformer secondary coil that contains twice as many loops as the primary coil will be
     a) less and the amperage greater than in the primary coil
     b) greater and the amperage greater than in the primary coil
     c) greater and the amperage less than in the primary coil

Answer 276

c) greater and the amperage less than in the primary coil

Question 277

277. How are generators rated?
     a) Impedance at rated voltage
     b) Amperes at rated voltage
     c) Watts at rated voltage

Answer 277

c) Watts at rated voltage

Question 278

278. in a single phase AC generator, frequency is determined by
     a) the generator speed
     b) controlling the current flow through the voltage field windings
     c) the number of pairs of poles

Answer 278

a) the generator speed

Question 279

279. The risk of a fire due to static electricity is overcome
     a) by fitting static wicks and insulating all metal components
     b) by connecting all metal components by bonding
     c) by fitting static wicks and isolating the battery from inflammable gas sources

Answer 279

b) by connecting all metal components by bonding

Question 280

280. Due to armature reaction in a DC motor
     a) the trailing pole tips are magnetically weakened
     b) the leading pole tips are magnetically weakened
     c) the magnetic flux is restored by moving the MNA towards the GNA

Answer 280

a) the trailing pole tips are magnetically weakened

Question 281

281. Two resistors are connected in series and have an e.m.f. of V volts across them. If the voltages across the resistances are V1 and V2 then by Kirchhoff’s law
     a) V = V1 + V2
     b) V2 = V1 + V
     c) V1 = V2 + V

Answer 281

a) V = V1 + V2

Question 282

282. When an electrical supply becomes open-circuit
     a) the loss of continuity will prevent its component from functioning
     b) the fuse or circuit breaker should isolate the circuit due to the increased current drawn
     c) the component will operate normally but will not switch off

Answer 282

a) the loss of continuity will prevent its component from functioning

Question 283

283. Some electric motors have two sets of field winding wound in opposite directions so that the
     a) speed of the motor can be more closely controlled
     b) motor can be operated in either direction
     c) power output of the motor can be more closely controlled

Answer 283

b) motor can be operated in either direction

Question 284

284. The amount of electrical power for a given generator weight is
     a) determined by the size of the aircraft
     b) greater for DC generator
     c) greater for AC generator

Answer 284

c) greater for AC generator

Question 285

285. When resistors are in parallel the total current is equal to
     a) the current through one resistor
     b) the sum of the currents
     c) the reciprocal of all the currents

Answer 285

b) the sum of the currents

Question 286

286. What is the ampere-hour rating of a storage battery that is designed to deliver 45 amperes for 2.5 hours?
     a) 90.0 ampere-hour
     b) 112.5 ampere-hour
     c) 45.0 ampere-hour

Answer 286

b) 112.5 ampere-hour

Question 287

287. How much power must a 24-volt generator furnish to a system which contains the following series loads?
     5 ohm, 3 ohm and 12 ohm
     a) 450 watts
     b) 402 watts
     c) 28.8 watts

Answer 287

c) 28.8 watts

Question 288

288. A volt meter is connected
     a) in series or parallel
     b) in parallel
     c) in series

Answer 288

b) in parallel

Question 289

289. What polarity do interpoles take in a DC motor?
     a) The same as the next main pole behind in the direction of rotation
     b) Either, provided they lay on the MNA
     c) The same as the next main pole ahead in the direction of rotation

Answer 289

a) The same as the next main pole behind in the direction of rotation

Question 290

290. On a typical AC generator the output is taken
     a) direct from the rotor via slip rings
     b) direct from the exciter
     c) direct from the stator windings

Answer 290

c) direct from the stator windings

Question 291

291. Since electrical supplies taken from a bus-bar are in parallel, isolating some of the services would
     a) reduce the current consumption from the bus-bar
     b) increase the current consumption from the busbar
     c) not affect the current consumption, it would reduce the voltage

Answer 291

a) reduce the current consumption from the bus-bar

Question 292

292. One Picofarad is
     a) 1 x 1012 farad
     b) 1 x 10-6 farad
     c) 1 x 10-12 farad

Answer 292

c) 1 x 10-12 farad

Question 293

293. Which of these will cause the resistance of a conductor to decrease?
     a) Decrease the length or the cross-sectional area
     b) Decrease the length or increase the cross-sectional area
     c) Increase the length or decrease the cross-sectional
     area

Answer 293

b) Decrease the length or increase the cross-sectional area

Question 294

294. The purpose of bonding is to
     a) give generated static an easy return path to the generator
     b) stop different potentials developing with subsequent fire risks
     c) ensure all components have been securely fitted

Answer 294

b) stop different potentials developing with subsequent fire risks

Question 295

295. The S.I. unit of magnetic flux density is the
     a) Weber
     b) Henry
     c) Tesla

Answer 295

c) Tesla

Question 296

296. What is the principal advantage of the series-wound dc motor?
     a) Low starting torque
     b) Suitable for constant speed use
     c) High starting torque

Answer 296

c) High starting torque

Question 297

297. Interpole windings fitted to DC series wound generators are
     a) in series with the field
     b) in parallel with the armature
     c) in series with the armature

Answer 297

c) in series with the armature

Question 298

298. One of the chief advantages of alternating current is that it can be transmitted at a high voltage with a low power loss; the voltage can then be changed to any desired value of
     a) AC by means of transformers
     b) DC by means of transformers
     c) DC by means of inverters

Answer 298

a) AC by means of transformers

Question 299

299. An AC generator is producing the required voltage but a higher frequency than that required. To remedy this, the following action must be taken?
     a) Decrease the speed of the prime mover, and then decrease the strength of the field
     b) Decrease the speed of the prime mover
     c) Decrease the speed of the prime mover, and then increase the strength of the field

Answer 299

c) Decrease the speed of the prime mover, and then increase the strength of the field

Question 300

300. How many amperes will a 28-volt generator be required to supply to a circuit containing five lamps in parallel, three of which have a resistance of 6 ohms each and two of which have a resistance of 5 ohms each?
     a) 25.23 amperes
     b) 1 ampere
     c) 1.11 amperes

Answer 300

a) 25.23 amperes

Question 301

301. The area of a hysteresis loop is proportional to the
     a) energy dissipated in putting the material through a complete cycle of magnetization and demagnetization
     b) relative permeability of the material being magnetized
     c) energy absorbed in completely demagnetizing the material

Answer 301

a) energy dissipated in putting the material through a complete cycle of magnetization and demagnetization

Question 302

302. The current flowing through a circuit can be increased to four times its original value by
     a) doubling the applied voltage and halving the resistance
     b) halving the applied voltage and halving the resistance
     c) doubling the resistance and doubling the applied voltage

Answer 302

a) doubling the applied voltage and halving the resistance

Question 303

303. When more than two inductors of different inductances are connected in parallel in a circuit, the total inductance is
     a) equal to the sum of the individual inductances
     b) less than the inductance of the lowest rated inductor
     c) equal to the inductance of the highest rated inductor

Answer 303

b) less than the inductance of the lowest rated inductor

Question 304

304. What polarity do interpoles take in a DC generator?
     a) the same as the next main pole ahead in the direction of rotation
     b) the same as the next main pole behind in the direction of rotation
     c) either, providing they lay on M.N.A.

Answer 304

a) the same as the next main pole ahead in the direction of rotation

Question 305

305. What happens to the resistance of a copper conductor when the temperature increases?
     a) It increases
     b) It decreases
     c) It remains the same

Answer 305

a) It increases

Question 306

306. The method most often used in overcoming the effect of armature reaction is through the use of
     a) shaded poles
     b) interpoles
     c) drum-wound armatures in combination with a negatively connected series field

Answer 306

b) interpoles

Question 307

307. The core material used for an electromagnet is soft iron because
     a) it demagnetizes easily
     b) it retains most of its flux density when demagnetized
     c)its magnetism is not easily destroyed

Answer 307

a) it demagnetizes easily

Question 308

308. The switch on a DC circuit containing a fully charged capacitor is opened. The voltage across the capacitor
     a) drops immediately to zero
     b) starts to fall exponentially to zero
     c) remains equal to the original charging voltage supply

Answer 308

c) remains equal to the original charging voltage supply

Question 309

309. in a 3 phase generator with balanced load, the potential between the neutral point and earth is
     a) equal to line volts
     b) equal to phase volts
     c) zero volts

Answer 309

c) zero volts

Question 310

310. A direct current of 12 milliamperes flows through a circuit which has a resistance of 1000 ohms. The power dissipated by the circuit is
     a) 12 milliwatts
     b) 12 watts
     c) 144 milliwatts

Answer 310

c) 144 milliwatts

Question 311

311. An increase in which of the following factors will cause an increase in the inductive reactance of a circuit?
     a) Resistance and capacitive reactance
     b) Resistance and voltage
     c) Inductance and frequency

Answer 311

c) Inductance and frequency

Question 312

312. in transformer operation, hysteresis losses are
     a) current overcoming coil resistance
     b) induced current in the iron core
     c) energy wasted in reversing core magnetization

Answer 312

c) energy wasted in reversing core magnetization

Question 313

313. The starting current of a series-wound DC motor, in passing through both the field and armature windings produces a
     a) low starting torque
     b) speed slightly higher when unloaded
     c) high starting torque

Answer 313

c) high starting torque

Question 314

314. A non-magnetic metal
     a) has no permeability
     b) has high retentivity
     c) is a poor conductor

Answer 314

a) has no permeability

Question 315

315. The power output of an AC parallel generator system is measured in
     a) KVA
     b) KW / KVARS
     c) amperes

Answer 315

b) KW / KVARS

Question 316

316. The shape of the output waveform of an AC generator is known as a
     a) sine wave
     b) cosine wave
     c) frequency wave

Answer 316

a) sine wave

Question 317

317. in a circuit containing three resistors of equal value connected in series and one of the resistors short circuits, the effect is for the current in the other two resistors to
     a) increase
     b) remain the same
     c) decrease

Answer 317

a) increase

Question 318

318. To increase the speed of a shunt motor a resistance is placed
     a) in series with the armature
     b) in parallel with the field
     c) in series with the field

Answer 318

c) in series with the field

Question 319

319. Frequency (Hz) is the number of cycles per
     a) revolution
     b) minute
     c) second

Answer 319

c) second

Question 320

320. In a series resistive circuit
     a) the total voltage equals the difference between the individual voltages
     b) the total voltage is equal to the sum of the individual voltages
     c) the total voltage is the same as the highest individual

Answer 320

b) the total voltage is equal to the sum of the individual voltages

Question 321

321. The current in a DC circuit containing a fully charged capacitor is
     a) zero
     b) is dependent upon the size of the capacitance of the capacitor
     c) maximum

Answer 321

a) zero

Question 322

322. The sum of the instantaneous E.M.F.’s in a three phase system is
     a) equal to the line voltage
     b) three times the phase voltage
     c) zero

Answer 322

c) zero

Question 323

323. A capacitor is a barrier to
     a) both
     b) A.C
     c) D.C

Answer 323

c) D.C

Question 324

324. One revolution of a three phase generator will
     produce
     a) 3 cycles
     b) 2 cycles
     c) 1 cycle

Answer 324

c) 1 cycle

Question 325

325. If the North pole of a magnet is brought nearer to the North pole of another magnet
     a) attraction between them will be increased
     b) repulsion between them will be increased
     c) repulsion between them will be reduced

Answer 325

b) repulsion between them will be increased

Question 326

326. A 200 volt motor is taking 10 amperes armature current, the armature resistance is 0.1 ohm. The B.EMF under these conditions will be
     a) 201 volts
     b) 199 volts
     c) 1 volt

Answer 326

b) 199 volts

Question 327

327. What is the effect of inserting an iron core into a current carrying coil?
     a) The flux density of the original magnetic field produced by the coil is increased
     b) The flux density of the original magnetic field remains constant
     c) The core tends to move from a stronger to a weaker part of the field

Answer 327

a) The flux density of the original magnetic field produced by the coil is increased

Question 328

328. What is the total capacitance of a parallel circuit containing three capacitors with capacitance of 0.25microfarad, 0.03microfarad, and 0.12microfarad, respectively?
     a) 0.04 µF
     b) 0.04 pF
     c) 0.4 µF

Answer 328

c) 0.4 µF

Question 329

329. At resonant frequency the phase difference between the voltage and current of an AC supply feeding an inductive and capacitive network is
     a) 0 degrees
     b) 180 degrees
     c) 90 degrees

Answer 329

a) 0 degrees

Question 330

330. The frequency of a power wave in an AC resistance circuit is
     a) the same as the frequency for voltage and current
     b) half the frequency for voltage and current
     c) twice the frequency for voltage and current

Answer 330

c) twice the frequency for voltage and current

Question 331

331. The reading on the ammeter in the circuit shown is
     a) 3A
     b) 6A
     c) 12A

Answer 331

b) 6A

Question 332

332. The ‘A’ phase of a three phase power system is colour coded
     a) blue
     b) yellow
     c) red

Answer 332

c) red

Question 333

333. The total resistance of the circuit shown is
     a) 12 Ohms
     b) 3 Ohms
     c) 7.5 Ohms

Answer 333

b) 3 Ohms

Question 334

334. What is a method used for restoring generator field residual magnetism?
     a) Flash the fields
     b) Reseat the brushes
     c) Energize the armature

Answer 334

a) Flash the fields

Question 335

335. A 1µF capacitor is equivalent to
     a) 0.000,001 Farads
     b) 1,000,000 Farads
     c) 0.001 Farads

Answer 335

a) 0.000,001 Farads

Question 336

336. The opposition offered by a coil to the flow of alternating current is called (disregard resistance)
     a) impedance
     b) reluctance
     c) inductive reactance

Answer 336

c) inductive reactance

Question 337

337. A high surge of current is required when a DC electric motor is first started. As the speed of the motor increase
     a) the applied emf increases proportionally
     b) the counter emf decreases proportionally
     c) the counter emf builds up and opposes the applied emf, thus reducing the current flow through the armature

Answer 337

c) the counter emf builds up and opposes the applied emf, thus reducing the current flow through the armature

Question 338

338. The tolerance of the AC generator frequency is
     a) 40 Hz
     b) 10 Hz
     c) 20 Hz

Answer 338

b) 10 Hz

Question 339

339. The various parts of an aircraft airframe are maintained at the same potential by
     a) the supply bus-bars
     b) static discharge wicks
     c) bonding

Answer 339

c) bonding

Question 340

340. When two capacitors are connected in series
     a) the charge stored on each is directly proportional to its capacitance
     b) the charge stored on each is the same
     c) the charge stored on each is inversely proportional to the voltage across it

Answer 340

b) the charge stored on each is the same

Question 341

341. Aircraft generators are cooled by
     a) oil cooling radiators around the main body
     b) fuel cooling radiators
     c) ram air

Answer 341

c) ram air

Question 342

342. The voltage of an AC generator
     a) rises to max in one direction, falls to zero and rises in the same direction
     b) rises to max in one direction then falls to zero then rises to max in the opposite direction
     c) rises to max in one direction and remains

Answer 342

b) rises to max in one direction then falls to zero then rises to max in the opposite direction

Question 343

343. The charge on a capacitor is expressed as
     a) the ratio Q/V
     b) the product Q x V
     c) the product C x V

Answer 343

c) the product C x V

Question 344

344. A shunt is used with
     a) an ammeter
     b) an ohmmeter
     c) a voltmeter

Answer 344

a) an ammeter

Question 345

345. The resistance of the current return path through the aircraft is always considered negligible, provided the
     a) generator is properly grounded
     b) voltage drop across the circuit is checked
     c) structure is adequately bonded

Answer 345

c) structure is adequately bonded

Question 346

346. An ammeter is connected into a circuit in
     a) parallel
     b) shunt
     c) series

Answer 346

c) series

Question 347

347. When handling a high voltage capacitor in an electrical circuit, be sure it
     a) has a full charge before removing it from the circuit
     b) is fully discharged before removing it from the circuit
     c) has at least a residual charge before removing it from the circuit

Answer 347

b) is fully discharged before removing it from the circuit

Question 348

348. When a circuit with a series inductance and capacitance is at resonant frequency
     a) the current in the circuit decreases
     b) the impedance of the circuit is such that the voltage is in phase with the current
     c) the impedance of the circuit is such that the voltage leads the current by exactly 90 degrees

Answer 348

b) the impedance of the circuit is such that the voltage is in phase with the current

Question 349

349. in an AC circuit, the effective voltage is
     a) equal to the maximum instantaneous voltage
     b) greater than the maximum instantaneous voltage
     c) less than the maximum instantaneous voltage

Answer 349

c) less than the maximum instantaneous voltage

Question 350

350. On a combined DC starter - generator system
     a) the voltage regulator is connected to the shunt field after the start cycle is completed
     b) the series coil is open circuit during the engine start sequence
     c) the voltage regulator controls the start sequence during engine starting

Answer 350

a) the voltage regulator is connected to the shunt field after the start cycle is completed

Question 351

351. A pure capacitor, inductor and resistor are connected in series and the voltage drops across each are 10V and the total current flowing in the circuit is 1A.
     How much true power is the circuit consuming?
     a) 30VA
     b) 30W
     c) 10W

Answer 351

c) 10W

Question 352

352. If a capacitor 1µF and an inductor 10mH are connected in parallel what is their approximate resonant frequency?
     a) 62Hz
     b) 3.2MHz
     c) 1.6kHz

Answer 352

c) 1.6kHz

Question 353

353. Which wave form is stepped positive and negative with unequal length sides?
     a) Trapezoidal wave
     b) Rectangular wave
     c) Saw tooth wave

Answer 353

a) Trapezoidal wave

Question 354

354. The value of an AC sine wave that will give an equivalent heating effect in a DC resistor is the
     a) average value
     b) RMS value
     c) peak value

Answer 354

b) RMS value

Question 355

355. Where is the magnetic dip least?
     a) Poles
     b) Equator
     c) Isoclinals

Answer 355

b) Equator

Question 356

356. The dielectric constant of a capacitor is a measurement of
     a) the electrostatic energy storing capacity of the capacitor dielectric
     b) the electrical resistance of the capacitor dielectric
     c) the electrical repulsion of electrons within the dielectric material

Answer 356

a) the electrostatic energy storing capacity of the capacitor dielectric

Question 357

357. To reverse the direction of rotation on a DC shunt motor, you must change the direction of the current through
     a) the field windings or the armature windings
     b) the armature windings only
     c) the field windings and the armature windings

Answer 357

a) the field windings or the armature windings

Question 358

358. If the field current to a shunt wound DC motor is decreased when operating at a constant load, the motor speed will
     a) reduce
     b) increase
     c) not change

Answer 358

b) increase

Question 359

359. An electric current is
     a) a surplus of free electron
     b) an excitement of electrons in a metal
     c) an ordered flow of electrons

Answer 359

c) an ordered flow of electrons

Question 360

360. An atom contains
     a) molecules
     b) hydrogen
     c) electrons

Answer 360

c) electrons

Question 361

361. What causes a transformer to be noisy?
     a) High coil resistance
     b) An air gap in the core
     c) High core losses

Answer 361

b) An air gap in the core

Question 362

362. Carbon has a
     a) negative temperature coefficient
     b) positive temperature coefficient
     c) temperature coefficient of zero

Answer 362

a) negative temperature coefficient

Question 363

363. The peak factor for a sine wave is
     a) 0.707
     b) 1.414
     c) 1.11

Answer 363

b) 1.414

Question 364

364. If a motor is spinning at 50 cycles per second, how long is 1 cycle?
     a) 0.02 seconds
     b) 50 seconds
     c) 0.83 seconds

Answer 364

a) 0.02 seconds

Question 365

365. An integrated step input at unequal time base produces
     a) a square wave
     b) a sine wave
     c) a saw tooth wave

Answer 365

c) a saw tooth wave

Question 366

366. A capacitor in series and inductor in parallel make what kind of filter?
     a) Band pass
     b) High pass
     c) Low pass

Answer 366

b) High pass

Question 367

367. If a load in series has a current passing through it, the magnetic field can be worked out by using
     a) the corkscrew rule
     b) left hand rule
     c) right hand rule

Answer 367

a) the corkscrew rule

Question 368

368. If the current flowing into a junction is 5A, 3A, 4A in and 10A out. What is the 5th wire carrying?
     a) 2A in
     b) 2A out
     c) 5A out

Answer 368

b) 2A out

Question 369

369. If an insulated conductor is placed near to a negatively charged rod, the nearest end of the conductor becomes
     a) negatively charged
     b) positively charged
     c) No change will occur

Answer 369

b) positively charged

Question 370

370. If 2 resistors, one red, yellow, black, gold and the other violet, blue, black, silver were replaced by a single resistor. Ignoring tolerance, what would the color coding
     be?
     a) Brown, black, brown
     b) Brown, black, black
     c) Black, brown, blac

Answer 370

a) Brown, black, brown

Question 371

371. Germanium and silicon have how many electrons in their outer shell
     a) 4
     b) 2
     c) 6

Answer 371

a) 4