Design and Integration of Electrical Power Systems in Aircraft: Power
Generation, Distribution, and Management: Multiple Choice Questions
(MCQ) with Answers
1. What is the typical voltage range for aircraft DC electrical systems?
a) 12-14V
b) 24-28V
c) 48-52V
d) 110-120V
Answer: b) 24-28V
2. Calculate the power output of an aircraft generator with a voltage of 115V and a current of 200A.
a) 11.5 kW
b) 23 kW
c) 2.3 kW
d) 230 kW
Answer: b) 23 kW
3. Which of the following is NOT a common type of aircraft generator?
a) Constant Frequency (CF) generator
b) Variable Frequency (VF) generator
c) Integrated Drive Generator (IDG)
d) Alternating Current (AC) generator
Answer: d) Alternating Current (AC) generator
4. If an aircraft's electrical system operates at 28V DC and draws 50A, what is the power
consumption?
a) 700 W
b) 1400 W
c) 560 W
d) 280 W
Answer: b) 1400 W
5. What is the typical frequency of AC power systems in modern aircraft?
a) 50 Hz
b) 60 Hz
c) 400 Hz
d) 1000 Hz
Answer: c) 400 Hz
6. An aircraft generator produces 115V AC at 400 Hz. What is the period of this waveform?
a) 0.0025 seconds
b) 0.025 seconds
c) 0.25 seconds
d) 2.5 seconds
Answer: a) 0.0025 seconds
7. In a three-phase AC system with 115V line-to-neutral voltage, what is the line-to-line voltage?
a) 115V
b) 199V
c) 230V
d) 400V
Answer: b) 199V
8. A 28V DC aircraft system has a 50Ah battery. How much energy can it store?
a) 700 Wh
b) 1400 Wh
c) 2800 Wh
d) 5000 Wh
Answer: b) 1400 Wh
9. What is the power factor of an ideal resistive load in an AC circuit?
a) 0
b) 0.5
c) 0.707
d) 1
Answer: d) 1
10. An aircraft electrical bus is rated at 115V AC and can handle 100A. What is its power capacity?
a) 5.75 kVA
b) 11.5 kVA
c) 23 kVA
d) 46 kVA
Answer: b) 11.5 kVA
11. If an aircraft generator produces 30 kVA at 0.8 power factor, what is the real power output?
a) 18 kW
b) 24 kW
c) 30 kW
d) 37.5 kW
Answer: b) 24 kW
12. What is the impedance of a 400 Hz AC circuit with 10 Ω resistance and 5 Ω inductive reactance?
a) 5 Ω
b) 10 Ω
c) 11.18 Ω
d) 15 Ω
Answer: c) 11.18 Ω
13. A 115V AC, 400 Hz aircraft system has a 20 μF capacitor. What is its reactance?
a) 19.9 Ω
b) 39.8 Ω
c) 79.6 Ω
d) 159.2 Ω
Answer: a) 19.9 Ω
14. What is the current drawn by a 1 kW resistive load on a 28V DC aircraft system?
a) 17.86 A
b) 28 A
c) 35.71 A
d) 57.14 A
Answer: c) 35.71 A
15. In a 400 Hz AC system, what is the inductive reactance of a 100 mH inductor?
a) 25.13 Ω
b) 251.3 Ω
c) 2513 Ω
d) 25130 Ω
Answer: b) 251.3 Ω
16. A transformer in an aircraft electrical system has a turns ratio of 2:1. If the primary voltage is
230V, what is the secondary voltage?
a) 57.5V
b) 115V
c) 230V
d) 460V
Answer: b) 115V
17. What is the time constant of an RC circuit with R = 100 kΩ and C = 10 μF?
a) 0.1 ms
b) 1 ms
c) 10 ms
d) 100 ms
Answer: b) 1 ms
18. An aircraft electrical system has a total load of 50 kVA at 0.9 power factor. What is the reactive
power?
a) 21.8 kVAR
b) 24.2 kVAR
c) 45 kVAR
d) 50 kVAR
Answer: a) 21.8 kVAR
19. What is the efficiency of a generator that produces 30 kW of electrical power while consuming 35
kW of mechanical power?
a) 75%
b) 80%
c) 85.7%
d) 90%
Answer: c) 85.7%
20. A 115V AC, 400 Hz aircraft system has a load with 10 Ω resistance and 5 Ω inductive reactance.
What is the power factor?
a) 0.5
b) 0.707
c) 0.894
d) 1
Answer: c) 0.894
21. What is the phase angle between voltage and current in a circuit with 8 Ω resistance and 6 Ω
capacitive reactance?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
22. An aircraft battery has an internal resistance of 0.05 Ω and an open-circuit voltage of 24V. What is
the terminal voltage when supplying 100A?
a) 19V
b) 21V
c) 23V
d) 24V
Answer: b) 21V
23. What is the skin depth of copper at 400 Hz, given that ρ = 1.68 × 10^-8 Ω·m and μr = 1?
a) 0.33 mm
b) 3.3 mm
c) 33 mm
d) 330 mm
Answer: a) 0.33 mm
24. A 115V AC, 400 Hz aircraft generator has a synchronous reactance of 0.5 Ω. What is its short-
circuit current?
a) 115 A
b) 230 A
c) 460 A
d) 920 A
Answer: b) 230 A
25. What is the power dissipated in a 50 Ω resistor when 2A RMS flows through it?
a) 100 W
b) 141.4 W
c) 200 W
d) 282.8 W
Answer: c) 200 W
26. An aircraft electrical system uses a 3-phase, 115/200V, 400 Hz supply. What is the line current if
the total load is 30 kVA at unity power factor?
a) 50 A
b) 86.6 A
c) 100 A
d) 173.2 A
Answer: b) 86.6 A
27. What is the resonant frequency of an LC circuit with L = 1 mH and C = 10 μF?
a) 1.59 kHz
b) 15.9 kHz
c) 159 kHz
d) 1.59 MHz
Answer: b) 15.9 kHz
28. A 28V DC aircraft system has a cable with 0.01 Ω/m resistance. What is the voltage drop over
10m when carrying 50A?
a) 2.8V
b) 5V
c) 14V
d) 28V
Answer: b) 5V
29. What is the Q factor of an inductor with L = 10 mH and R = 2 Ω at 400 Hz?
a) 12.57
b) 25.13
c) 50.27
d) 100.53
Answer: b) 25.13
30. An aircraft generator produces 115V AC. What is the peak voltage?
a) 81.32V
b) 115V
c) 162.63V
d) 230V
Answer: c) 162.63V
31. What is the total capacitance of two 10 μF capacitors connected in series?
a) 2.5 μF
b) 5 μF
c) 10 μF
d) 20 μF
Answer: b) 5 μF
32. An aircraft electrical system has a power factor of 0.8 lagging. What is the phase angle between
voltage and current?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
33. What is the RMS value of a 28V DC signal?
a) 19.8V
b) 28V
c) 39.6V
d) 56V
Answer: b) 28V
34. A 400 Hz transformer has 500 turns on the primary and 100 turns on the secondary. If the
primary voltage is 230V, what is the secondary voltage?
a) 23V
b) 46V
c) 115V
d) 1150V
Answer: b) 46V
35. What is the time constant of an RL circuit with R = 50 Ω and L = 100 mH?
a) 0.5 ms
b) 1 ms
c) 2 ms
d) 5 ms
Answer: c) 2 ms
36. An aircraft electrical system has a total impedance of 10 Ω at 30°. What is the resistance
component?
a) 5 Ω
b) 7.07 Ω
c) 8.66 Ω
d) 10 Ω
Answer: c) 8.66 Ω
37. What is the power dissipated in a 10 Ω resistor when 5V RMS is applied across it?
a) 1.25 W
b) 2.5 W
c) 5 W
d) 10 W
Answer: b) 2.5 W
38. A 115V AC, 400 Hz aircraft system has a load drawing 10A at 0.8 power factor. What is the
apparent power?
a) 920 VA
b) 1150 VA
c) 1437.5 VA
d) 1800 VA
Answer: b) 1150 VA
39. What is the inductance of a coil that has a reactance of 100 Ω at 400 Hz?
a) 39.8 mH
b) 79.6 mH
c) 159.2 mH
d) 318.3 mH
Answer: a) 39.8 mH
40. An aircraft generator rated at 30 kVA, 0.8 power factor is operating at full load. What is the
reactive power output?
a) 12 kVAR
b) 18 kVAR
c) 24 kVAR
d) 30 kVAR
Answer: b) 18 kVAR
41. What is the impedance of a parallel RLC circuit at resonance, if R = 100 Ω, L = 10 mH, and C = 1
μF?
a) 0 Ω
b) 50 Ω
c) 100 Ω
d) 200 Ω
Answer: c) 100 Ω
42. A 28V DC aircraft system has a 100 Ah battery. How long can it supply a constant 10A load?
a) 5 hours
b) 7 hours
c) 10 hours
d) 14 hours
Answer: c) 10 hours
43. What is the power factor of a circuit with 12 Ω resistance and 5 Ω inductive reactance?
a) 0.707
b) 0.8
c) 0.923
d) 0.96
Answer: c) 0.923
44. An aircraft electrical system has a total load of 40 kW at 0.9 power factor. What is the apparent
power?
a) 36 kVA
b) 40 kVA
c) 44.4 kVA
d) 50 kVA
Answer: c) 44.4 kVA
45. What is the capacitance needed to correct the power factor of a 10 kVA, 0.8 lagging load to unity
power factor in a 115V, 400 Hz system?
a) 129 μF
b) 258 μF
c) 387 μF
d) 516 μF
Answer: b) 258 μF
46. A 115V AC, 400 Hz aircraft system has a load with 5 Ω resistance and 12 Ω capacitive reactance.
What is the power factor?
a) 0.384
b) 0.5
c) 0.707
d) 0.866
Answer: a) 0.384
47. What is the efficiency of a transformer with 100W input power and 95W output power?
a) 90%
b) 93%
c) 95%
d) 97%
Answer: c) 95%
48. An aircraft electrical bus carries 50A at 115V AC. What is the minimum wire gauge (AWG)
required if the maximum allowed current density is 5 A/mm²?
a) 8 AWG
b) 10 AWG
c) 12 AWG
d) 14 AWG
Answer: b) 10 AWG
49. What is the total resistance of three 30 Ω resistors connected in parallel?
a) 5 Ω
b) 10 Ω
c) 15 Ω
d) 90 Ω
Answer: b) 10 Ω
50. A 400 Hz aircraft generator has 4 poles. What is its rotational speed in RPM?
a) 3000 RPM
b) 6000 RPM
c) 12000 RPM
d) 24000 RPM
Answer: b) 6000 RPM
51. What is the phase difference between line-to-line voltages in a balanced three-phase system?
a) 60°
b) 90°
c) 120°
d) 180°
Answer: c) 120°
A 115V AC, 400 Hz aircraft system has a 20 μF capacitor. What is its reactance?
a) 19.9 Ω
b) 39.8 Ω
c) 79.6 Ω
d) 159.2 Ω
Answer: a) 19.9 Ω
14. What is the current drawn by a 1 kW resistive load on a 28V DC aircraft system?
a) 17.86 A
b) 28 A
c) 35.71 A
d) 57.14 A
Answer: c) 35.71 A
15. In a 400 Hz AC system, what is the inductive reactance of a 100 mH inductor?
a) 25.13 Ω
b) 251.3 Ω
c) 2513 Ω
d) 25130 Ω
Answer: b) 251.3 Ω
16. A transformer in an aircraft electrical system has a turns ratio of 2:1. If the primary voltage is
230V, what is the secondary voltage?
a) 57.5V
b) 115V
c) 230V
d) 460V
Answer: b) 115V
17. What is the time constant of an RC circuit with R = 100 kΩ and C = 10 μF?
a) 0.1 ms
b) 1 ms
c) 10 ms
d) 100 ms
Answer: b) 1 ms
18. An aircraft electrical system has a total load of 50 kVA at 0.9 power factor. What is the reactive
power?
a) 21.8 kVAR
b) 24.2 kVAR
c) 45 kVAR
d) 50 kVAR
Answer: a) 21.8 kVAR
19. What is the efficiency of a generator that produces 30 kW of electrical power while consuming 35
kW of mechanical power?
a) 75%
b) 80%
c) 85.7%
d) 90%
Answer: c) 85.7%
20. A 115V AC, 400 Hz aircraft system has a load with 10 Ω resistance and 5 Ω inductive reactance.
What is the power factor?
a) 0.5
b) 0.707
c) 0.894
d) 1
Answer: c) 0.894
21. What is the phase angle between voltage and current in a circuit with 8 Ω resistance and 6 Ω
capacitive reactance?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
22. An aircraft battery has an internal resistance of 0.05 Ω and an open-circuit voltage of 24V. What is
the terminal voltage when supplying 100A?
a) 19V
b) 21V
c) 23V
d) 24V
Answer: b) 21V
23. What is the skin depth of copper at 400 Hz, given that ρ = 1.68 × 10^-8 Ω·m and μr = 1?
a) 0.33 mm
b) 3.3 mm
c) 33 mm
d) 330 mm
Answer: a) 0.33 mm
24. A 115V AC, 400 Hz aircraft generator has a synchronous reactance of 0.5 Ω. What is its short-
circuit current?
a) 115 A
b) 230 A
c) 460 A
d) 920 A
Answer: b) 230 A
25. What is the power dissipated in a 50 Ω resistor when 2A RMS flows through it?
a) 100 W
b) 141.4 W
c) 200 W
d) 282.8 W
Answer: c) 200 W
26. An aircraft electrical system uses a 3-phase, 115/200V, 400 Hz supply. What is the line current if
the total load is 30 kVA at unity power factor?
a) 50 A
b) 86.6 A
c) 100 A
d) 173.2 A
Answer: b) 86.6 A
27. What is the resonant frequency of an LC circuit with L = 1 mH and C = 10 μF?
a) 1.59 kHz
b) 15.9 kHz
c) 159 kHz
d) 1.59 MHz
Answer: b) 15.9 kHz
28. A 28V DC aircraft system has a cable with 0.01 Ω/m resistance. What is the voltage drop over
10m when carrying 50A?
a) 2.8V
b) 5V
c) 14V
d) 28V
Answer: b) 5V
29. What is the Q factor of an inductor with L = 10 mH and R = 2 Ω at 400 Hz?
a) 12.57
b) 25.13
c) 50.27
d) 100.53
Answer: b) 25.13
30. An aircraft generator produces 115V AC. What is the peak voltage?
a) 81.32V
b) 115V
c) 162.63V
d) 230V
Answer: c) 162.63V
31. What is the total capacitance of two 10 μF capacitors connected in series?
a) 2.5 μF
b) 5 μF
c) 10 μF
d) 20 μF
Answer: b) 5 μF
32. An aircraft electrical system has a power factor of 0.8 lagging. What is the phase angle between
voltage and current?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
33. What is the RMS value of a 28V DC signal?
a) 19.8V
b) 28V
c) 39.6V
d) 56V
Answer: b) 28V
34. A 400 Hz transformer has 500 turns on the primary and 100 turns on the secondary. If the
primary voltage is 230V, what is the secondary voltage?
a) 23V
b) 46V
c) 115V
d) 1150V
Answer: b) 46V
35. What is the time constant of an RL circuit with R = 50 Ω and L = 100 mH?
a) 0.5 ms
b) 1 ms
c) 2 ms
d) 5 ms
Answer: c) 2 ms
36. An aircraft electrical system has a total impedance of 10 Ω at 30°. What is the resistance
component?
a) 5 Ω
b) 7.07 Ω
c) 8.66 Ω
d) 10 Ω
Answer: c) 8.66 Ω
37. What is the power dissipated in a 10 Ω resistor when 5V RMS is applied across it?
a) 1.25 W
b) 2.5 W
c) 5 W
d) 10 W
Answer: b) 2.5 W
38. A 115V AC, 400 Hz aircraft system has a load drawing 10A at 0.8 power factor. What is the
apparent power?
a) 920 VA
b) 1150 VA
c) 1437.5 VA
d) 1800 VA
Answer: b) 1150 VA
39. What is the inductance of a coil that has a reactance of 100 Ω at 400 Hz?
a) 39.8 mH
b) 79.6 mH
c) 159.2 mH
d) 318.3 mH
Answer: a) 39.8 mH
40. An aircraft generator rated at 30 kVA, 0.8 power factor is operating at full load. What is the
reactive power output?
a) 12 kVAR
b) 18 kVAR
c) 24 kVAR
d) 30 kVAR
Answer: b) 18 kVAR
41. What is the impedance of a parallel RLC circuit at resonance, if R = 100 Ω, L = 10 mH, and C = 1
μF?
a) 0 Ω
b) 50 Ω
c) 100 Ω
d) 200 Ω
Answer: c) 100 Ω
42. A 28V DC aircraft system has a 100 Ah battery. How long can it supply a constant 10A load?
a) 5 hours
b) 7 hours
c) 10 hours
d) 14 hours
Answer: c) 10 hours
43. What is the power factor of a circuit with 12 Ω resistance and 5 Ω inductive reactance?
a) 0.707
b) 0.8
c) 0.923
d) 0.96
Answer: c) 0.923
44. An aircraft electrical system has a total load of 40 kW at 0.9 power factor. What is the apparent
power?
a) 36 kVA
b) 40 kVA
c) 44.4 kVA
d) 50 kVA
Answer: c) 44.4 kVA
45. What is the capacitance needed to correct the power factor of a 10 kVA, 0.8 lagging load to unity
power factor in a 115V, 400 Hz system?
a) 129 μF
b) 258 μF
c) 387 μF
d) 516 μF
Answer: b) 258 μF
46. A 115V AC, 400 Hz aircraft system has a load with 5 Ω resistance and 12 Ω capacitive reactance.
What is the power factor?
a) 0.384
b) 0.5
c) 0.707
d) 0.866
Answer: a) 0.384
47. What is the efficiency of a transformer with 100W input power and 95W output power?
a) 90%
b) 93%
c) 95%
d) 97%
Answer: c) 95%
48. An aircraft electrical bus carries 50A at 115V AC. What is the minimum wire gauge (AWG)
required if the maximum allowed current density is 5 A/mm²?
a) 8 AWG
b) 10 AWG
c) 12 AWG
d) 14 AWG
Answer: b) 10 AWG
49. What is the total resistance of three 30 Ω resistors connected in parallel?
a) 5 Ω
b) 10 Ω
c) 15 Ω
d) 90 Ω
Answer: b) 10 Ω
50. A 400 Hz aircraft generator has 4 poles. What is its rotational speed in RPM?
a) 3000 RPM
b) 6000 RPM
c) 12000 RPM
d) 24000 RPM
Answer: b) 6000 RPM
51. What is the phase difference between line-to-line voltages in a balanced three-phase system?
a) 60°
b) 90°
c) 120°
d) 180°
Answer: c) 120°
A 115V AC, 400 Hz aircraft system has a 20 μF capacitor. What is its reactance?
a) 19.9 Ω
b) 39.8 Ω
c) 79.6 Ω
d) 159.2 Ω
Answer: a) 19.9 Ω
14. What is the current drawn by a 1 kW resistive load on a 28V DC aircraft system?
a) 17.86 A
b) 28 A
c) 35.71 A
d) 57.14 A
Answer: c) 35.71 A
15. In a 400 Hz AC system, what is the inductive reactance of a 100 mH inductor?
a) 25.13 Ω
b) 251.3 Ω
c) 2513 Ω
d) 25130 Ω
Answer: b) 251.3 Ω
16. A transformer in an aircraft electrical system has a turns ratio of 2:1. If the primary voltage is
230V, what is the secondary voltage?
a) 57.5V
b) 115V
c) 230V
d) 460V
Answer: b) 115V
17. What is the time constant of an RC circuit with R = 100 kΩ and C = 10 μF?
a) 0.1 ms
b) 1 ms
c) 10 ms
d) 100 ms
Answer: b) 1 ms
18. An aircraft electrical system has a total load of 50 kVA at 0.9 power factor. What is the reactive
power?
a) 21.8 kVAR
b) 24.2 kVAR
c) 45 kVAR
d) 50 kVAR
Answer: a) 21.8 kVAR
19. What is the efficiency of a generator that produces 30 kW of electrical power while consuming 35
kW of mechanical power?
a) 75%
b) 80%
c) 85.7%
d) 90%
Answer: c) 85.7%
20. A 115V AC, 400 Hz aircraft system has a load with 10 Ω resistance and 5 Ω inductive reactance.
What is the power factor?
a) 0.5
b) 0.707
c) 0.894
d) 1
Answer: c) 0.894
21. What is the phase angle between voltage and current in a circuit with 8 Ω resistance and 6 Ω
capacitive reactance?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
22. An aircraft battery has an internal resistance of 0.05 Ω and an open-circuit voltage of 24V. What is
the terminal voltage when supplying 100A?
a) 19V
b) 21V
c) 23V
d) 24V
Answer: b) 21V
23. What is the skin depth of copper at 400 Hz, given that ρ = 1.68 × 10^-8 Ω·m and μr = 1?
a) 0.33 mm
b) 3.3 mm
c) 33 mm
d) 330 mm
Answer: a) 0.33 mm
24. A 115V AC, 400 Hz aircraft generator has a synchronous reactance of 0.5 Ω. What is its short-
circuit current?
a) 115 A
b) 230 A
c) 460 A
d) 920 A
Answer: b) 230 A
25. What is the power dissipated in a 50 Ω resistor when 2A RMS flows through it?
a) 100 W
b) 141.4 W
c) 200 W
d) 282.8 W
Answer: c) 200 W
26. An aircraft electrical system uses a 3-phase, 115/200V, 400 Hz supply. What is the line current if
the total load is 30 kVA at unity power factor?
a) 50 A
b) 86.6 A
c) 100 A
d) 173.2 A
Answer: b) 86.6 A
27. What is the resonant frequency of an LC circuit with L = 1 mH and C = 10 μF?
a) 1.59 kHz
b) 15.9 kHz
c) 159 kHz
d) 1.59 MHz
Answer: b) 15.9 kHz
28. A 28V DC aircraft system has a cable with 0.01 Ω/m resistance. What is the voltage drop over
10m when carrying 50A?
a) 2.8V
b) 5V
c) 14V
d) 28V
Answer: b) 5V
29. What is the Q factor of an inductor with L = 10 mH and R = 2 Ω at 400 Hz?
a) 12.57
b) 25.13
c) 50.27
d) 100.53
Answer: b) 25.13
30. An aircraft generator produces 115V AC. What is the peak voltage?
a) 81.32V
b) 115V
c) 162.63V
d) 230V
Answer: c) 162.63V
31. What is the total capacitance of two 10 μF capacitors connected in series?
a) 2.5 μF
b) 5 μF
c) 10 μF
d) 20 μF
Answer: b) 5 μF
32. An aircraft electrical system has a power factor of 0.8 lagging. What is the phase angle between
voltage and current?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
33. What is the RMS value of a 28V DC signal?
a) 19.8V
b) 28V
c) 39.6V
d) 56V
Answer: b) 28V
34. A 400 Hz transformer has 500 turns on the primary and 100 turns on the secondary. If the
primary voltage is 230V, what is the secondary voltage?
a) 23V
b) 46V
c) 115V
d) 1150V
Answer: b) 46V
35. What is the time constant of an RL circuit with R = 50 Ω and L = 100 mH?
a) 0.5 ms
b) 1 ms
c) 2 ms
d) 5 ms
Answer: c) 2 ms
36. An aircraft electrical system has a total impedance of 10 Ω at 30°. What is the resistance
component?
a) 5 Ω
b) 7.07 Ω
c) 8.66 Ω
d) 10 Ω
Answer: c) 8.66 Ω
37. What is the power dissipated in a 10 Ω resistor when 5V RMS is applied across it?
a) 1.25 W
b) 2.5 W
c) 5 W
d) 10 W
Answer: b) 2.5 W
38. A 115V AC, 400 Hz aircraft system has a load drawing 10A at 0.8 power factor. What is the
apparent power?
a) 920 VA
b) 1150 VA
c) 1437.5 VA
d) 1800 VA
Answer: b) 1150 VA
39. What is the inductance of a coil that has a reactance of 100 Ω at 400 Hz?
a) 39.8 mH
b) 79.6 mH
c) 159.2 mH
d) 318.3 mH
Answer: a) 39.8 mH
40. An aircraft generator rated at 30 kVA, 0.8 power factor is operating at full load. What is the
reactive power output?
a) 12 kVAR
b) 18 kVAR
c) 24 kVAR
d) 30 kVAR
Answer: b) 18 kVAR
41. What is the impedance of a parallel RLC circuit at resonance, if R = 100 Ω, L = 10 mH, and C = 1
μF?
a) 0 Ω
b) 50 Ω
c) 100 Ω
d) 200 Ω
Answer: c) 100 Ω
42. A 28V DC aircraft system has a 100 Ah battery. How long can it supply a constant 10A load?
a) 5 hours
b) 7 hours
c) 10 hours
d) 14 hours
Answer: c) 10 hours
43. What is the power factor of a circuit with 12 Ω resistance and 5 Ω inductive reactance?
a) 0.707
b) 0.8
c) 0.923
d) 0.96
Answer: c) 0.923
44. An aircraft electrical system has a total load of 40 kW at 0.9 power factor. What is the apparent
power?
a) 36 kVA
b) 40 kVA
c) 44.4 kVA
d) 50 kVA
Answer: c) 44.4 kVA
45. What is the capacitance needed to correct the power factor of a 10 kVA, 0.8 lagging load to unity
power factor in a 115V, 400 Hz system?
a) 129 μF
b) 258 μF
c) 387 μF
d) 516 μF
Answer: b) 258 μF
46. A 115V AC, 400 Hz aircraft system has a load with 5 Ω resistance and 12 Ω capacitive reactance.
What is the power factor?
a) 0.384
b) 0.5
c) 0.707
d) 0.866
Answer: a) 0.384
47. What is the efficiency of a transformer with 100W input power and 95W output power?
a) 90%
b) 93%
c) 95%
d) 97%
Answer: c) 95%
48. An aircraft electrical bus carries 50A at 115V AC. What is the minimum wire gauge (AWG)
required if the maximum allowed current density is 5 A/mm²?
a) 8 AWG
b) 10 AWG
c) 12 AWG
d) 14 AWG
Answer: b) 10 AWG
49. What is the total resistance of three 30 Ω resistors connected in parallel?
a) 5 Ω
b) 10 Ω
c) 15 Ω
d) 90 Ω
Answer: b) 10 Ω
50. A 400 Hz aircraft generator has 4 poles. What is its rotational speed in RPM?
a) 3000 RPM
b) 6000 RPM
c) 12000 RPM
d) 24000 RPM
Answer: b) 6000 RPM
51. What is the phase difference between line-to-line voltages in a balanced three-phase system?
a) 60°
b) 90°
c) 120°
d) 180°
Answer: c) 120°
A 115V AC, 400 Hz aircraft system has a 20 μF capacitor. What is its reactance?
a) 19.9 Ω
b) 39.8 Ω
c) 79.6 Ω
d) 159.2 Ω
Answer: a) 19.9 Ω
14. What is the current drawn by a 1 kW resistive load on a 28V DC aircraft system?
a) 17.86 A
b) 28 A
c) 35.71 A
d) 57.14 A
Answer: c) 35.71 A
15. In a 400 Hz AC system, what is the inductive reactance of a 100 mH inductor?
a) 25.13 Ω
b) 251.3 Ω
c) 2513 Ω
d) 25130 Ω
Answer: b) 251.3 Ω
16. A transformer in an aircraft electrical system has a turns ratio of 2:1. If the primary voltage is
230V, what is the secondary voltage?
a) 57.5V
b) 115V
c) 230V
d) 460V
Answer: b) 115V
17. What is the time constant of an RC circuit with R = 100 kΩ and C = 10 μF?
a) 0.1 ms
b) 1 ms
c) 10 ms
d) 100 ms
Answer: b) 1 ms
18. An aircraft electrical system has a total load of 50 kVA at 0.9 power factor. What is the reactive
power?
a) 21.8 kVAR
b) 24.2 kVAR
c) 45 kVAR
d) 50 kVAR
Answer: a) 21.8 kVAR
19. What is the efficiency of a generator that produces 30 kW of electrical power while consuming 35
kW of mechanical power?
a) 75%
b) 80%
c) 85.7%
d) 90%
Answer: c) 85.7%
20. A 115V AC, 400 Hz aircraft system has a load with 10 Ω resistance and 5 Ω inductive reactance.
What is the power factor?
a) 0.5
b) 0.707
c) 0.894
d) 1
Answer: c) 0.894
21. What is the phase angle between voltage and current in a circuit with 8 Ω resistance and 6 Ω
capacitive reactance?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
22. An aircraft battery has an internal resistance of 0.05 Ω and an open-circuit voltage of 24V. What is
the terminal voltage when supplying 100A?
a) 19V
b) 21V
c) 23V
d) 24V
Answer: b) 21V
23. What is the skin depth of copper at 400 Hz, given that ρ = 1.68 × 10^-8 Ω·m and μr = 1?
a) 0.33 mm
b) 3.3 mm
c) 33 mm
d) 330 mm
Answer: a) 0.33 mm
24. A 115V AC, 400 Hz aircraft generator has a synchronous reactance of 0.5 Ω. What is its short-
circuit current?
a) 115 A
b) 230 A
c) 460 A
d) 920 A
Answer: b) 230 A
25. What is the power dissipated in a 50 Ω resistor when 2A RMS flows through it?
a) 100 W
b) 141.4 W
c) 200 W
d) 282.8 W
Answer: c) 200 W
26. An aircraft electrical system uses a 3-phase, 115/200V, 400 Hz supply. What is the line current if
the total load is 30 kVA at unity power factor?
a) 50 A
b) 86.6 A
c) 100 A
d) 173.2 A
Answer: b) 86.6 A
27. What is the resonant frequency of an LC circuit with L = 1 mH and C = 10 μF?
a) 1.59 kHz
b) 15.9 kHz
c) 159 kHz
d) 1.59 MHz
Answer: b) 15.9 kHz
28. A 28V DC aircraft system has a cable with 0.01 Ω/m resistance. What is the voltage drop over
10m when carrying 50A?
a) 2.8V
b) 5V
c) 14V
d) 28V
Answer: b) 5V
29. What is the Q factor of an inductor with L = 10 mH and R = 2 Ω at 400 Hz?
a) 12.57
b) 25.13
c) 50.27
d) 100.53
Answer: b) 25.13
30. An aircraft generator produces 115V AC. What is the peak voltage?
a) 81.32V
b) 115V
c) 162.63V
d) 230V
Answer: c) 162.63V
31. What is the total capacitance of two 10 μF capacitors connected in series?
a) 2.5 μF
b) 5 μF
c) 10 μF
d) 20 μF
Answer: b) 5 μF
32. An aircraft electrical system has a power factor of 0.8 lagging. What is the phase angle between
voltage and current?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
33. What is the RMS value of a 28V DC signal?
a) 19.8V
b) 28V
c) 39.6V
d) 56V
Answer: b) 28V
34. A 400 Hz transformer has 500 turns on the primary and 100 turns on the secondary. If the
primary voltage is 230V, what is the secondary voltage?
a) 23V
b) 46V
c) 115V
d) 1150V
Answer: b) 46V
35. What is the time constant of an RL circuit with R = 50 Ω and L = 100 mH?
a) 0.5 ms
b) 1 ms
c) 2 ms
d) 5 ms
Answer: c) 2 ms
36. An aircraft electrical system has a total impedance of 10 Ω at 30°. What is the resistance
component?
a) 5 Ω
b) 7.07 Ω
c) 8.66 Ω
d) 10 Ω
Answer: c) 8.66 Ω
37. What is the power dissipated in a 10 Ω resistor when 5V RMS is applied across it?
a) 1.25 W
b) 2.5 W
c) 5 W
d) 10 W
Answer: b) 2.5 W
38. A 115V AC, 400 Hz aircraft system has a load drawing 10A at 0.8 power factor. What is the
apparent power?
a) 920 VA
b) 1150 VA
c) 1437.5 VA
d) 1800 VA
Answer: b) 1150 VA
39. What is the inductance of a coil that has a reactance of 100 Ω at 400 Hz?
a) 39.8 mH
b) 79.6 mH
c) 159.2 mH
d) 318.3 mH
Answer: a) 39.8 mH
40. An aircraft generator rated at 30 kVA, 0.8 power factor is operating at full load. What is the
reactive power output?
a) 12 kVAR
b) 18 kVAR
c) 24 kVAR
d) 30 kVAR
Answer: b) 18 kVAR
41. What is the impedance of a parallel RLC circuit at resonance, if R = 100 Ω, L = 10 mH, and C = 1
μF?
a) 0 Ω
b) 50 Ω
c) 100 Ω
d) 200 Ω
Answer: c) 100 Ω
42. A 28V DC aircraft system has a 100 Ah battery. How long can it supply a constant 10A load?
a) 5 hours
b) 7 hours
c) 10 hours
d) 14 hours
Answer: c) 10 hours
43. What is the power factor of a circuit with 12 Ω resistance and 5 Ω inductive reactance?
a) 0.707
b) 0.8
c) 0.923
d) 0.96
Answer: c) 0.923
44. An aircraft electrical system has a total load of 40 kW at 0.9 power factor. What is the apparent
power?
a) 36 kVA
b) 40 kVA
c) 44.4 kVA
d) 50 kVA
Answer: c) 44.4 kVA
45. What is the capacitance needed to correct the power factor of a 10 kVA, 0.8 lagging load to unity
power factor in a 115V, 400 Hz system?
a) 129 μF
b) 258 μF
c) 387 μF
d) 516 μF
Answer: b) 258 μF
46. A 115V AC, 400 Hz aircraft system has a load with 5 Ω resistance and 12 Ω capacitive reactance.
What is the power factor?
a) 0.384
b) 0.5
c) 0.707
d) 0.866
Answer: a) 0.384
47. What is the efficiency of a transformer with 100W input power and 95W output power?
a) 90%
b) 93%
c) 95%
d) 97%
Answer: c) 95%
48. An aircraft electrical bus carries 50A at 115V AC. What is the minimum wire gauge (AWG)
required if the maximum allowed current density is 5 A/mm²?
a) 8 AWG
b) 10 AWG
c) 12 AWG
d) 14 AWG
Answer: b) 10 AWG
49. What is the total resistance of three 30 Ω resistors connected in parallel?
a) 5 Ω
b) 10 Ω
c) 15 Ω
d) 90 Ω
Answer: b) 10 Ω
50. A 400 Hz aircraft generator has 4 poles. What is its rotational speed in RPM?
a) 3000 RPM
b) 6000 RPM
c) 12000 RPM
d) 24000 RPM
Answer: b) 6000 RPM
51. What is the phase difference between line-to-line voltages in a balanced three-phase system?
a) 60°
b) 90°
c) 120°
d) 180°
Answer: c) 120°
A 115V AC, 400 Hz aircraft system has a 20 μF capacitor. What is its reactance?
a) 19.9 Ω
b) 39.8 Ω
c) 79.6 Ω
d) 159.2 Ω
Answer: a) 19.9 Ω
14. What is the current drawn by a 1 kW resistive load on a 28V DC aircraft system?
a) 17.86 A
b) 28 A
c) 35.71 A
d) 57.14 A
Answer: c) 35.71 A
15. In a 400 Hz AC system, what is the inductive reactance of a 100 mH inductor?
a) 25.13 Ω
b) 251.3 Ω
c) 2513 Ω
d) 25130 Ω
Answer: b) 251.3 Ω
16. A transformer in an aircraft electrical system has a turns ratio of 2:1. If the primary voltage is
230V, what is the secondary voltage?
a) 57.5V
b) 115V
c) 230V
d) 460V
Answer: b) 115V
17. What is the time constant of an RC circuit with R = 100 kΩ and C = 10 μF?
a) 0.1 ms
b) 1 ms
c) 10 ms
d) 100 ms
Answer: b) 1 ms
18. An aircraft electrical system has a total load of 50 kVA at 0.9 power factor. What is the reactive
power?
a) 21.8 kVAR
b) 24.2 kVAR
c) 45 kVAR
d) 50 kVAR
Answer: a) 21.8 kVAR
19. What is the efficiency of a generator that produces 30 kW of electrical power while consuming 35
kW of mechanical power?
a) 75%
b) 80%
c) 85.7%
d) 90%
Answer: c) 85.7%
20. A 115V AC, 400 Hz aircraft system has a load with 10 Ω resistance and 5 Ω inductive reactance.
What is the power factor?
a) 0.5
b) 0.707
c) 0.894
d) 1
Answer: c) 0.894
21. What is the phase angle between voltage and current in a circuit with 8 Ω resistance and 6 Ω
capacitive reactance?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
22. An aircraft battery has an internal resistance of 0.05 Ω and an open-circuit voltage of 24V. What is
the terminal voltage when supplying 100A?
a) 19V
b) 21V
c) 23V
d) 24V
Answer: b) 21V
23. What is the skin depth of copper at 400 Hz, given that ρ = 1.68 × 10^-8 Ω·m and μr = 1?
a) 0.33 mm
b) 3.3 mm
c) 33 mm
d) 330 mm
Answer: a) 0.33 mm
24. A 115V AC, 400 Hz aircraft generator has a synchronous reactance of 0.5 Ω. What is its short-
circuit current?
a) 115 A
b) 230 A
c) 460 A
d) 920 A
Answer: b) 230 A
25. What is the power dissipated in a 50 Ω resistor when 2A RMS flows through it?
a) 100 W
b) 141.4 W
c) 200 W
d) 282.8 W
Answer: c) 200 W
26. An aircraft electrical system uses a 3-phase, 115/200V, 400 Hz supply. What is the line current if
the total load is 30 kVA at unity power factor?
a) 50 A
b) 86.6 A
c) 100 A
d) 173.2 A
Answer: b) 86.6 A
27. What is the resonant frequency of an LC circuit with L = 1 mH and C = 10 μF?
a) 1.59 kHz
b) 15.9 kHz
c) 159 kHz
d) 1.59 MHz
Answer: b) 15.9 kHz
28. A 28V DC aircraft system has a cable with 0.01 Ω/m resistance. What is the voltage drop over
10m when carrying 50A?
a) 2.8V
b) 5V
c) 14V
d) 28V
Answer: b) 5V
29. What is the Q factor of an inductor with L = 10 mH and R = 2 Ω at 400 Hz?
a) 12.57
b) 25.13
c) 50.27
d) 100.53
Answer: b) 25.13
30. An aircraft generator produces 115V AC. What is the peak voltage?
a) 81.32V
b) 115V
c) 162.63V
d) 230V
Answer: c) 162.63V
31. What is the total capacitance of two 10 μF capacitors connected in series?
a) 2.5 μF
b) 5 μF
c) 10 μF
d) 20 μF
Answer: b) 5 μF
32. An aircraft electrical system has a power factor of 0.8 lagging. What is the phase angle between
voltage and current?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
33. What is the RMS value of a 28V DC signal?
a) 19.8V
b) 28V
c) 39.6V
d) 56V
Answer: b) 28V
34. A 400 Hz transformer has 500 turns on the primary and 100 turns on the secondary. If the
primary voltage is 230V, what is the secondary voltage?
a) 23V
b) 46V
c) 115V
d) 1150V
Answer: b) 46V
35. What is the time constant of an RL circuit with R = 50 Ω and L = 100 mH?
a) 0.5 ms
b) 1 ms
c) 2 ms
d) 5 ms
Answer: c) 2 ms
36. An aircraft electrical system has a total impedance of 10 Ω at 30°. What is the resistance
component?
a) 5 Ω
b) 7.07 Ω
c) 8.66 Ω
d) 10 Ω
Answer: c) 8.66 Ω
37. What is the power dissipated in a 10 Ω resistor when 5V RMS is applied across it?
a) 1.25 W
b) 2.5 W
c) 5 W
d) 10 W
Answer: b) 2.5 W
38. A 115V AC, 400 Hz aircraft system has a load drawing 10A at 0.8 power factor. What is the
apparent power?
a) 920 VA
b) 1150 VA
c) 1437.5 VA
d) 1800 VA
Answer: b) 1150 VA
39. What is the inductance of a coil that has a reactance of 100 Ω at 400 Hz?
a) 39.8 mH
b) 79.6 mH
c) 159.2 mH
d) 318.3 mH
Answer: a) 39.8 mH
40. An aircraft generator rated at 30 kVA, 0.8 power factor is operating at full load. What is the
reactive power output?
a) 12 kVAR
b) 18 kVAR
c) 24 kVAR
d) 30 kVAR
Answer: b) 18 kVAR
41. What is the impedance of a parallel RLC circuit at resonance, if R = 100 Ω, L = 10 mH, and C = 1
μF?
a) 0 Ω
b) 50 Ω
c) 100 Ω
d) 200 Ω
Answer: c) 100 Ω
42. A 28V DC aircraft system has a 100 Ah battery. How long can it supply a constant 10A load?
a) 5 hours
b) 7 hours
c) 10 hours
d) 14 hours
Answer: c) 10 hours
43. What is the power factor of a circuit with 12 Ω resistance and 5 Ω inductive reactance?
a) 0.707
b) 0.8
c) 0.923
d) 0.96
Answer: c) 0.923
44. An aircraft electrical system has a total load of 40 kW at 0.9 power factor. What is the apparent
power?
a) 36 kVA
b) 40 kVA
c) 44.4 kVA
d) 50 kVA
Answer: c) 44.4 kVA
45. What is the capacitance needed to correct the power factor of a 10 kVA, 0.8 lagging load to unity
power factor in a 115V, 400 Hz system?
a) 129 μF
b) 258 μF
c) 387 μF
d) 516 μF
Answer: b) 258 μF
46. A 115V AC, 400 Hz aircraft system has a load with 5 Ω resistance and 12 Ω capacitive reactance.
What is the power factor?
a) 0.384
b) 0.5
c) 0.707
d) 0.866
Answer: a) 0.384
47. What is the efficiency of a transformer with 100W input power and 95W output power?
a) 90%
b) 93%
c) 95%
d) 97%
Answer: c) 95%
48. An aircraft electrical bus carries 50A at 115V AC. What is the minimum wire gauge (AWG)
required if the maximum allowed current density is 5 A/mm²?
a) 8 AWG
b) 10 AWG
c) 12 AWG
d) 14 AWG
Answer: b) 10 AWG
49. What is the total resistance of three 30 Ω resistors connected in parallel?
a) 5 Ω
b) 10 Ω
c) 15 Ω
d) 90 Ω
Answer: b) 10 Ω
50. A 400 Hz aircraft generator has 4 poles. What is its rotational speed in RPM?
a) 3000 RPM
b) 6000 RPM
c) 12000 RPM
d) 24000 RPM
Answer: b) 6000 RPM
51. What is the phase difference between line-to-line voltages in a balanced three-phase system?
a) 60°
b) 90°
c) 120°
d) 180°
Answer: c) 120°
A 115V AC, 400 Hz aircraft system has a 20 μF capacitor. What is its reactance?
a) 19.9 Ω
b) 39.8 Ω
c) 79.6 Ω
d) 159.2 Ω
Answer: a) 19.9 Ω
14. What is the current drawn by a 1 kW resistive load on a 28V DC aircraft system?
a) 17.86 A
b) 28 A
c) 35.71 A
d) 57.14 A
Answer: c) 35.71 A
15. In a 400 Hz AC system, what is the inductive reactance of a 100 mH inductor?
a) 25.13 Ω
b) 251.3 Ω
c) 2513 Ω
d) 25130 Ω
Answer: b) 251.3 Ω
16. A transformer in an aircraft electrical system has a turns ratio of 2:1. If the primary voltage is
230V, what is the secondary voltage?
a) 57.5V
b) 115V
c) 230V
d) 460V
Answer: b) 115V
17. What is the time constant of an RC circuit with R = 100 kΩ and C = 10 μF?
a) 0.1 ms
b) 1 ms
c) 10 ms
d) 100 ms
Answer: b) 1 ms
18. An aircraft electrical system has a total load of 50 kVA at 0.9 power factor. What is the reactive
power?
a) 21.8 kVAR
b) 24.2 kVAR
c) 45 kVAR
d) 50 kVAR
Answer: a) 21.8 kVAR
19. What is the efficiency of a generator that produces 30 kW of electrical power while consuming 35
kW of mechanical power?
a) 75%
b) 80%
c) 85.7%
d) 90%
Answer: c) 85.7%
20. A 115V AC, 400 Hz aircraft system has a load with 10 Ω resistance and 5 Ω inductive reactance.
What is the power factor?
a) 0.5
b) 0.707
c) 0.894
d) 1
Answer: c) 0.894
21. What is the phase angle between voltage and current in a circuit with 8 Ω resistance and 6 Ω
capacitive reactance?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
22. An aircraft battery has an internal resistance of 0.05 Ω and an open-circuit voltage of 24V. What is
the terminal voltage when supplying 100A?
a) 19V
b) 21V
c) 23V
d) 24V
Answer: b) 21V
23. What is the skin depth of copper at 400 Hz, given that ρ = 1.68 × 10^-8 Ω·m and μr = 1?
a) 0.33 mm
b) 3.3 mm
c) 33 mm
d) 330 mm
Answer: a) 0.33 mm
24. A 115V AC, 400 Hz aircraft generator has a synchronous reactance of 0.5 Ω. What is its short-
circuit current?
a) 115 A
b) 230 A
c) 460 A
d) 920 A
Answer: b) 230 A
25. What is the power dissipated in a 50 Ω resistor when 2A RMS flows through it?
a) 100 W
b) 141.4 W
c) 200 W
d) 282.8 W
Answer: c) 200 W
26. An aircraft electrical system uses a 3-phase, 115/200V, 400 Hz supply. What is the line current if
the total load is 30 kVA at unity power factor?
a) 50 A
b) 86.6 A
c) 100 A
d) 173.2 A
Answer: b) 86.6 A
27. What is the resonant frequency of an LC circuit with L = 1 mH and C = 10 μF?
a) 1.59 kHz
b) 15.9 kHz
c) 159 kHz
d) 1.59 MHz
Answer: b) 15.9 kHz
28. A 28V DC aircraft system has a cable with 0.01 Ω/m resistance. What is the voltage drop over
10m when carrying 50A?
a) 2.8V
b) 5V
c) 14V
d) 28V
Answer: b) 5V
29. What is the Q factor of an inductor with L = 10 mH and R = 2 Ω at 400 Hz?
a) 12.57
b) 25.13
c) 50.27
d) 100.53
Answer: b) 25.13
30. An aircraft generator produces 115V AC. What is the peak voltage?
a) 81.32V
b) 115V
c) 162.63V
d) 230V
Answer: c) 162.63V
31. What is the total capacitance of two 10 μF capacitors connected in series?
a) 2.5 μF
b) 5 μF
c) 10 μF
d) 20 μF
Answer: b) 5 μF
32. An aircraft electrical system has a power factor of 0.8 lagging. What is the phase angle between
voltage and current?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
33. What is the RMS value of a 28V DC signal?
a) 19.8V
b) 28V
c) 39.6V
d) 56V
Answer: b) 28V
34. A 400 Hz transformer has 500 turns on the primary and 100 turns on the secondary. If the
primary voltage is 230V, what is the secondary voltage?
a) 23V
b) 46V
c) 115V
d) 1150V
Answer: b) 46V
35. What is the time constant of an RL circuit with R = 50 Ω and L = 100 mH?
a) 0.5 ms
b) 1 ms
c) 2 ms
d) 5 ms
Answer: c) 2 ms
36. An aircraft electrical system has a total impedance of 10 Ω at 30°. What is the resistance
component?
a) 5 Ω
b) 7.07 Ω
c) 8.66 Ω
d) 10 Ω
Answer: c) 8.66 Ω
37. What is the power dissipated in a 10 Ω resistor when 5V RMS is applied across it?
a) 1.25 W
b) 2.5 W
c) 5 W
d) 10 W
Answer: b) 2.5 W
38. A 115V AC, 400 Hz aircraft system has a load drawing 10A at 0.8 power factor. What is the
apparent power?
a) 920 VA
b) 1150 VA
c) 1437.5 VA
d) 1800 VA
Answer: b) 1150 VA
39. What is the inductance of a coil that has a reactance of 100 Ω at 400 Hz?
a) 39.8 mH
b) 79.6 mH
c) 159.2 mH
d) 318.3 mH
Answer: a) 39.8 mH
40. An aircraft generator rated at 30 kVA, 0.8 power factor is operating at full load. What is the
reactive power output?
a) 12 kVAR
b) 18 kVAR
c) 24 kVAR
d) 30 kVAR
Answer: b) 18 kVAR
41. What is the impedance of a parallel RLC circuit at resonance, if R = 100 Ω, L = 10 mH, and C = 1
μF?
a) 0 Ω
b) 50 Ω
c) 100 Ω
d) 200 Ω
Answer: c) 100 Ω
42. A 28V DC aircraft system has a 100 Ah battery. How long can it supply a constant 10A load?
a) 5 hours
b) 7 hours
c) 10 hours
d) 14 hours
Answer: c) 10 hours
43. What is the power factor of a circuit with 12 Ω resistance and 5 Ω inductive reactance?
a) 0.707
b) 0.8
c) 0.923
d) 0.96
Answer: c) 0.923
44. An aircraft electrical system has a total load of 40 kW at 0.9 power factor. What is the apparent
power?
a) 36 kVA
b) 40 kVA
c) 44.4 kVA
d) 50 kVA
Answer: c) 44.4 kVA
45. What is the capacitance needed to correct the power factor of a 10 kVA, 0.8 lagging load to unity
power factor in a 115V, 400 Hz system?
a) 129 μF
b) 258 μF
c) 387 μF
d) 516 μF
Answer: b) 258 μF
46. A 115V AC, 400 Hz aircraft system has a load with 5 Ω resistance and 12 Ω capacitive reactance.
What is the power factor?
a) 0.384
b) 0.5
c) 0.707
d) 0.866
Answer: a) 0.384
47. What is the efficiency of a transformer with 100W input power and 95W output power?
a) 90%
b) 93%
c) 95%
d) 97%
Answer: c) 95%
48. An aircraft electrical bus carries 50A at 115V AC. What is the minimum wire gauge (AWG)
required if the maximum allowed current density is 5 A/mm²?
a) 8 AWG
b) 10 AWG
c) 12 AWG
d) 14 AWG
Answer: b) 10 AWG
49. What is the total resistance of three 30 Ω resistors connected in parallel?
a) 5 Ω
b) 10 Ω
c) 15 Ω
d) 90 Ω
Answer: b) 10 Ω
50. A 400 Hz aircraft generator has 4 poles. What is its rotational speed in RPM?
a) 3000 RPM
b) 6000 RPM
c) 12000 RPM
d) 24000 RPM
Answer: b) 6000 RPM
51. What is the phase difference between line-to-line voltages in a balanced three-phase system?
a) 60°
b) 90°
c) 120°
d) 180°
Answer: c) 120°
A 115V AC, 400 Hz aircraft system has a 20 μF capacitor. What is its reactance?
a) 19.9 Ω
b) 39.8 Ω
c) 79.6 Ω
d) 159.2 Ω
Answer: a) 19.9 Ω
14. What is the current drawn by a 1 kW resistive load on a 28V DC aircraft system?
a) 17.86 A
b) 28 A
c) 35.71 A
d) 57.14 A
Answer: c) 35.71 A
15. In a 400 Hz AC system, what is the inductive reactance of a 100 mH inductor?
a) 25.13 Ω
b) 251.3 Ω
c) 2513 Ω
d) 25130 Ω
Answer: b) 251.3 Ω
16. A transformer in an aircraft electrical system has a turns ratio of 2:1. If the primary voltage is
230V, what is the secondary voltage?
a) 57.5V
b) 115V
c) 230V
d) 460V
Answer: b) 115V
17. What is the time constant of an RC circuit with R = 100 kΩ and C = 10 μF?
a) 0.1 ms
b) 1 ms
c) 10 ms
d) 100 ms
Answer: b) 1 ms
18. An aircraft electrical system has a total load of 50 kVA at 0.9 power factor. What is the reactive
power?
a) 21.8 kVAR
b) 24.2 kVAR
c) 45 kVAR
d) 50 kVAR
Answer: a) 21.8 kVAR
19. What is the efficiency of a generator that produces 30 kW of electrical power while consuming 35
kW of mechanical power?
a) 75%
b) 80%
c) 85.7%
d) 90%
Answer: c) 85.7%
20. A 115V AC, 400 Hz aircraft system has a load with 10 Ω resistance and 5 Ω inductive reactance.
What is the power factor?
a) 0.5
b) 0.707
c) 0.894
d) 1
Answer: c) 0.894
21. What is the phase angle between voltage and current in a circuit with 8 Ω resistance and 6 Ω
capacitive reactance?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
22. An aircraft battery has an internal resistance of 0.05 Ω and an open-circuit voltage of 24V. What is
the terminal voltage when supplying 100A?
a) 19V
b) 21V
c) 23V
d) 24V
Answer: b) 21V
23. What is the skin depth of copper at 400 Hz, given that ρ = 1.68 × 10^-8 Ω·m and μr = 1?
a) 0.33 mm
b) 3.3 mm
c) 33 mm
d) 330 mm
Answer: a) 0.33 mm
24. A 115V AC, 400 Hz aircraft generator has a synchronous reactance of 0.5 Ω. What is its short-
circuit current?
a) 115 A
b) 230 A
c) 460 A
d) 920 A
Answer: b) 230 A
25. What is the power dissipated in a 50 Ω resistor when 2A RMS flows through it?
a) 100 W
b) 141.4 W
c) 200 W
d) 282.8 W
Answer: c) 200 W
26. An aircraft electrical system uses a 3-phase, 115/200V, 400 Hz supply. What is the line current if
the total load is 30 kVA at unity power factor?
a) 50 A
b) 86.6 A
c) 100 A
d) 173.2 A
Answer: b) 86.6 A
27. What is the resonant frequency of an LC circuit with L = 1 mH and C = 10 μF?
a) 1.59 kHz
b) 15.9 kHz
c) 159 kHz
d) 1.59 MHz
Answer: b) 15.9 kHz
28. A 28V DC aircraft system has a cable with 0.01 Ω/m resistance. What is the voltage drop over
10m when carrying 50A?
a) 2.8V
b) 5V
c) 14V
d) 28V
Answer: b) 5V
29. What is the Q factor of an inductor with L = 10 mH and R = 2 Ω at 400 Hz?
a) 12.57
b) 25.13
c) 50.27
d) 100.53
Answer: b) 25.13
30. An aircraft generator produces 115V AC. What is the peak voltage?
a) 81.32V
b) 115V
c) 162.63V
d) 230V
Answer: c) 162.63V
31. What is the total capacitance of two 10 μF capacitors connected in series?
a) 2.5 μF
b) 5 μF
c) 10 μF
d) 20 μF
Answer: b) 5 μF
32. An aircraft electrical system has a power factor of 0.8 lagging. What is the phase angle between
voltage and current?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
33. What is the RMS value of a 28V DC signal?
a) 19.8V
b) 28V
c) 39.6V
d) 56V
Answer: b) 28V
34. A 400 Hz transformer has 500 turns on the primary and 100 turns on the secondary. If the
primary voltage is 230V, what is the secondary voltage?
a) 23V
b) 46V
c) 115V
d) 1150V
Answer: b) 46V
35. What is the time constant of an RL circuit with R = 50 Ω and L = 100 mH?
a) 0.5 ms
b) 1 ms
c) 2 ms
d) 5 ms
Answer: c) 2 ms
36. An aircraft electrical system has a total impedance of 10 Ω at 30°. What is the resistance
component?
a) 5 Ω
b) 7.07 Ω
c) 8.66 Ω
d) 10 Ω
Answer: c) 8.66 Ω
37. What is the power dissipated in a 10 Ω resistor when 5V RMS is applied across it?
a) 1.25 W
b) 2.5 W
c) 5 W
d) 10 W
Answer: b) 2.5 W
38. A 115V AC, 400 Hz aircraft system has a load drawing 10A at 0.8 power factor. What is the
apparent power?
a) 920 VA
b) 1150 VA
c) 1437.5 VA
d) 1800 VA
Answer: b) 1150 VA
39. What is the inductance of a coil that has a reactance of 100 Ω at 400 Hz?
a) 39.8 mH
b) 79.6 mH
c) 159.2 mH
d) 318.3 mH
Answer: a) 39.8 mH
40. An aircraft generator rated at 30 kVA, 0.8 power factor is operating at full load. What is the
reactive power output?
a) 12 kVAR
b) 18 kVAR
c) 24 kVAR
d) 30 kVAR
Answer: b) 18 kVAR
41. What is the impedance of a parallel RLC circuit at resonance, if R = 100 Ω, L = 10 mH, and C = 1
μF?
a) 0 Ω
b) 50 Ω
c) 100 Ω
d) 200 Ω
Answer: c) 100 Ω
42. A 28V DC aircraft system has a 100 Ah battery. How long can it supply a constant 10A load?
a) 5 hours
b) 7 hours
c) 10 hours
d) 14 hours
Answer: c) 10 hours
43. What is the power factor of a circuit with 12 Ω resistance and 5 Ω inductive reactance?
a) 0.707
b) 0.8
c) 0.923
d) 0.96
Answer: c) 0.923
44. An aircraft electrical system has a total load of 40 kW at 0.9 power factor. What is the apparent
power?
a) 36 kVA
b) 40 kVA
c) 44.4 kVA
d) 50 kVA
Answer: c) 44.4 kVA
45. What is the capacitance needed to correct the power factor of a 10 kVA, 0.8 lagging load to unity
power factor in a 115V, 400 Hz system?
a) 129 μF
b) 258 μF
c) 387 μF
d) 516 μF
Answer: b) 258 μF
46. A 115V AC, 400 Hz aircraft system has a load with 5 Ω resistance and 12 Ω capacitive reactance.
What is the power factor?
a) 0.384
b) 0.5
c) 0.707
d) 0.866
Answer: a) 0.384
47. What is the efficiency of a transformer with 100W input power and 95W output power?
a) 90%
b) 93%
c) 95%
d) 97%
Answer: c) 95%
48. An aircraft electrical bus carries 50A at 115V AC. What is the minimum wire gauge (AWG)
required if the maximum allowed current density is 5 A/mm²?
a) 8 AWG
b) 10 AWG
c) 12 AWG
d) 14 AWG
Answer: b) 10 AWG
49. What is the total resistance of three 30 Ω resistors connected in parallel?
a) 5 Ω
b) 10 Ω
c) 15 Ω
d) 90 Ω
Answer: b) 10 Ω
50. A 400 Hz aircraft generator has 4 poles. What is its rotational speed in RPM?
a) 3000 RPM
b) 6000 RPM
c) 12000 RPM
d) 24000 RPM
Answer: b) 6000 RPM
51. What is the phase difference between line-to-line voltages in a balanced three-phase system?
a) 60°
b) 90°
c) 120°
d) 180°
Answer: c) 120°
A 115V AC, 400 Hz aircraft system has a 20 μF capacitor. What is its reactance?
a) 19.9 Ω
b) 39.8 Ω
c) 79.6 Ω
d) 159.2 Ω
Answer: a) 19.9 Ω
14. What is the current drawn by a 1 kW resistive load on a 28V DC aircraft system?
a) 17.86 A
b) 28 A
c) 35.71 A
d) 57.14 A
Answer: c) 35.71 A
15. In a 400 Hz AC system, what is the inductive reactance of a 100 mH inductor?
a) 25.13 Ω
b) 251.3 Ω
c) 2513 Ω
d) 25130 Ω
Answer: b) 251.3 Ω
16. A transformer in an aircraft electrical system has a turns ratio of 2:1. If the primary voltage is
230V, what is the secondary voltage?
a) 57.5V
b) 115V
c) 230V
d) 460V
Answer: b) 115V
17. What is the time constant of an RC circuit with R = 100 kΩ and C = 10 μF?
a) 0.1 ms
b) 1 ms
c) 10 ms
d) 100 ms
Answer: b) 1 ms
18. An aircraft electrical system has a total load of 50 kVA at 0.9 power factor. What is the reactive
power?
a) 21.8 kVAR
b) 24.2 kVAR
c) 45 kVAR
d) 50 kVAR
Answer: a) 21.8 kVAR
19. What is the efficiency of a generator that produces 30 kW of electrical power while consuming 35
kW of mechanical power?
a) 75%
b) 80%
c) 85.7%
d) 90%
Answer: c) 85.7%
20. A 115V AC, 400 Hz aircraft system has a load with 10 Ω resistance and 5 Ω inductive reactance.
What is the power factor?
a) 0.5
b) 0.707
c) 0.894
d) 1
Answer: c) 0.894
21. What is the phase angle between voltage and current in a circuit with 8 Ω resistance and 6 Ω
capacitive reactance?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
22. An aircraft battery has an internal resistance of 0.05 Ω and an open-circuit voltage of 24V. What is
the terminal voltage when supplying 100A?
a) 19V
b) 21V
c) 23V
d) 24V
Answer: b) 21V
23. What is the skin depth of copper at 400 Hz, given that ρ = 1.68 × 10^-8 Ω·m and μr = 1?
a) 0.33 mm
b) 3.3 mm
c) 33 mm
d) 330 mm
Answer: a) 0.33 mm
24. A 115V AC, 400 Hz aircraft generator has a synchronous reactance of 0.5 Ω. What is its short-
circuit current?
a) 115 A
b) 230 A
c) 460 A
d) 920 A
Answer: b) 230 A
25. What is the power dissipated in a 50 Ω resistor when 2A RMS flows through it?
a) 100 W
b) 141.4 W
c) 200 W
d) 282.8 W
Answer: c) 200 W
26. An aircraft electrical system uses a 3-phase, 115/200V, 400 Hz supply. What is the line current if
the total load is 30 kVA at unity power factor?
a) 50 A
b) 86.6 A
c) 100 A
d) 173.2 A
Answer: b) 86.6 A
27. What is the resonant frequency of an LC circuit with L = 1 mH and C = 10 μF?
a) 1.59 kHz
b) 15.9 kHz
c) 159 kHz
d) 1.59 MHz
Answer: b) 15.9 kHz
28. A 28V DC aircraft system has a cable with 0.01 Ω/m resistance. What is the voltage drop over
10m when carrying 50A?
a) 2.8V
b) 5V
c) 14V
d) 28V
Answer: b) 5V
29. What is the Q factor of an inductor with L = 10 mH and R = 2 Ω at 400 Hz?
a) 12.57
b) 25.13
c) 50.27
d) 100.53
Answer: b) 25.13
30. An aircraft generator produces 115V AC. What is the peak voltage?
a) 81.32V
b) 115V
c) 162.63V
d) 230V
Answer: c) 162.63V
31. What is the total capacitance of two 10 μF capacitors connected in series?
a) 2.5 μF
b) 5 μF
c) 10 μF
d) 20 μF
Answer: b) 5 μF
32. An aircraft electrical system has a power factor of 0.8 lagging. What is the phase angle between
voltage and current?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
33. What is the RMS value of a 28V DC signal?
a) 19.8V
b) 28V
c) 39.6V
d) 56V
Answer: b) 28V
34. A 400 Hz transformer has 500 turns on the primary and 100 turns on the secondary. If the
primary voltage is 230V, what is the secondary voltage?
a) 23V
b) 46V
c) 115V
d) 1150V
Answer: b) 46V
35. What is the time constant of an RL circuit with R = 50 Ω and L = 100 mH?
a) 0.5 ms
b) 1 ms
c) 2 ms
d) 5 ms
Answer: c) 2 ms
36. An aircraft electrical system has a total impedance of 10 Ω at 30°. What is the resistance
component?
a) 5 Ω
b) 7.07 Ω
c) 8.66 Ω
d) 10 Ω
Answer: c) 8.66 Ω
37. What is the power dissipated in a 10 Ω resistor when 5V RMS is applied across it?
a) 1.25 W
b) 2.5 W
c) 5 W
d) 10 W
Answer: b) 2.5 W
38. A 115V AC, 400 Hz aircraft system has a load drawing 10A at 0.8 power factor. What is the
apparent power?
a) 920 VA
b) 1150 VA
c) 1437.5 VA
d) 1800 VA
Answer: b) 1150 VA
39. What is the inductance of a coil that has a reactance of 100 Ω at 400 Hz?
a) 39.8 mH
b) 79.6 mH
c) 159.2 mH
d) 318.3 mH
Answer: a) 39.8 mH
40. An aircraft generator rated at 30 kVA, 0.8 power factor is operating at full load. What is the
reactive power output?
a) 12 kVAR
b) 18 kVAR
c) 24 kVAR
d) 30 kVAR
Answer: b) 18 kVAR
41. What is the impedance of a parallel RLC circuit at resonance, if R = 100 Ω, L = 10 mH, and C = 1
μF?
a) 0 Ω
b) 50 Ω
c) 100 Ω
d) 200 Ω
Answer: c) 100 Ω
42. A 28V DC aircraft system has a 100 Ah battery. How long can it supply a constant 10A load?
a) 5 hours
b) 7 hours
c) 10 hours
d) 14 hours
Answer: c) 10 hours
43. What is the power factor of a circuit with 12 Ω resistance and 5 Ω inductive reactance?
a) 0.707
b) 0.8
c) 0.923
d) 0.96
Answer: c) 0.923
44. An aircraft electrical system has a total load of 40 kW at 0.9 power factor. What is the apparent
power?
a) 36 kVA
b) 40 kVA
c) 44.4 kVA
d) 50 kVA
Answer: c) 44.4 kVA
45. What is the capacitance needed to correct the power factor of a 10 kVA, 0.8 lagging load to unity
power factor in a 115V, 400 Hz system?
a) 129 μF
b) 258 μF
c) 387 μF
d) 516 μF
Answer: b) 258 μF
46. A 115V AC, 400 Hz aircraft system has a load with 5 Ω resistance and 12 Ω capacitive reactance.
What is the power factor?
a) 0.384
b) 0.5
c) 0.707
d) 0.866
Answer: a) 0.384
47. What is the efficiency of a transformer with 100W input power and 95W output power?
a) 90%
b) 93%
c) 95%
d) 97%
Answer: c) 95%
48. An aircraft electrical bus carries 50A at 115V AC. What is the minimum wire gauge (AWG)
required if the maximum allowed current density is 5 A/mm²?
a) 8 AWG
b) 10 AWG
c) 12 AWG
d) 14 AWG
Answer: b) 10 AWG
49. What is the total resistance of three 30 Ω resistors connected in parallel?
a) 5 Ω
b) 10 Ω
c) 15 Ω
d) 90 Ω
Answer: b) 10 Ω
50. A 400 Hz aircraft generator has 4 poles. What is its rotational speed in RPM?
a) 3000 RPM
b) 6000 RPM
c) 12000 RPM
d) 24000 RPM
Answer: b) 6000 RPM
51. What is the phase difference between line-to-line voltages in a balanced three-phase system?
a) 60°
b) 90°
c) 120°
d) 180°
Answer: c) 120°
A 115V AC, 400 Hz aircraft system has a 20 μF capacitor. What is its reactance?
a) 19.9 Ω
b) 39.8 Ω
c) 79.6 Ω
d) 159.2 Ω
Answer: a) 19.9 Ω
14. What is the current drawn by a 1 kW resistive load on a 28V DC aircraft system?
a) 17.86 A
b) 28 A
c) 35.71 A
d) 57.14 A
Answer: c) 35.71 A
15. In a 400 Hz AC system, what is the inductive reactance of a 100 mH inductor?
a) 25.13 Ω
b) 251.3 Ω
c) 2513 Ω
d) 25130 Ω
Answer: b) 251.3 Ω
16. A transformer in an aircraft electrical system has a turns ratio of 2:1. If the primary voltage is
230V, what is the secondary voltage?
a) 57.5V
b) 115V
c) 230V
d) 460V
Answer: b) 115V
17. What is the time constant of an RC circuit with R = 100 kΩ and C = 10 μF?
a) 0.1 ms
b) 1 ms
c) 10 ms
d) 100 ms
Answer: b) 1 ms
18. An aircraft electrical system has a total load of 50 kVA at 0.9 power factor. What is the reactive
power?
a) 21.8 kVAR
b) 24.2 kVAR
c) 45 kVAR
d) 50 kVAR
Answer: a) 21.8 kVAR
19. What is the efficiency of a generator that produces 30 kW of electrical power while consuming 35
kW of mechanical power?
a) 75%
b) 80%
c) 85.7%
d) 90%
Answer: c) 85.7%
20. A 115V AC, 400 Hz aircraft system has a load with 10 Ω resistance and 5 Ω inductive reactance.
What is the power factor?
a) 0.5
b) 0.707
c) 0.894
d) 1
Answer: c) 0.894
21. What is the phase angle between voltage and current in a circuit with 8 Ω resistance and 6 Ω
capacitive reactance?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
22. An aircraft battery has an internal resistance of 0.05 Ω and an open-circuit voltage of 24V. What is
the terminal voltage when supplying 100A?
a) 19V
b) 21V
c) 23V
d) 24V
Answer: b) 21V
23. What is the skin depth of copper at 400 Hz, given that ρ = 1.68 × 10^-8 Ω·m and μr = 1?
a) 0.33 mm
b) 3.3 mm
c) 33 mm
d) 330 mm
Answer: a) 0.33 mm
24. A 115V AC, 400 Hz aircraft generator has a synchronous reactance of 0.5 Ω. What is its short-
circuit current?
a) 115 A
b) 230 A
c) 460 A
d) 920 A
Answer: b) 230 A
25. What is the power dissipated in a 50 Ω resistor when 2A RMS flows through it?
a) 100 W
b) 141.4 W
c) 200 W
d) 282.8 W
Answer: c) 200 W
26. An aircraft electrical system uses a 3-phase, 115/200V, 400 Hz supply. What is the line current if
the total load is 30 kVA at unity power factor?
a) 50 A
b) 86.6 A
c) 100 A
d) 173.2 A
Answer: b) 86.6 A
27. What is the resonant frequency of an LC circuit with L = 1 mH and C = 10 μF?
a) 1.59 kHz
b) 15.9 kHz
c) 159 kHz
d) 1.59 MHz
Answer: b) 15.9 kHz
28. A 28V DC aircraft system has a cable with 0.01 Ω/m resistance. What is the voltage drop over
10m when carrying 50A?
a) 2.8V
b) 5V
c) 14V
d) 28V
Answer: b) 5V
29. What is the Q factor of an inductor with L = 10 mH and R = 2 Ω at 400 Hz?
a) 12.57
b) 25.13
c) 50.27
d) 100.53
Answer: b) 25.13
30. An aircraft generator produces 115V AC. What is the peak voltage?
a) 81.32V
b) 115V
c) 162.63V
d) 230V
Answer: c) 162.63V
31. What is the total capacitance of two 10 μF capacitors connected in series?
a) 2.5 μF
b) 5 μF
c) 10 μF
d) 20 μF
Answer: b) 5 μF
32. An aircraft electrical system has a power factor of 0.8 lagging. What is the phase angle between
voltage and current?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
33. What is the RMS value of a 28V DC signal?
a) 19.8V
b) 28V
c) 39.6V
d) 56V
Answer: b) 28V
34. A 400 Hz transformer has 500 turns on the primary and 100 turns on the secondary. If the
primary voltage is 230V, what is the secondary voltage?
a) 23V
b) 46V
c) 115V
d) 1150V
Answer: b) 46V
35. What is the time constant of an RL circuit with R = 50 Ω and L = 100 mH?
a) 0.5 ms
b) 1 ms
c) 2 ms
d) 5 ms
Answer: c) 2 ms
36. An aircraft electrical system has a total impedance of 10 Ω at 30°. What is the resistance
component?
a) 5 Ω
b) 7.07 Ω
c) 8.66 Ω
d) 10 Ω
Answer: c) 8.66 Ω
37. What is the power dissipated in a 10 Ω resistor when 5V RMS is applied across it?
a) 1.25 W
b) 2.5 W
c) 5 W
d) 10 W
Answer: b) 2.5 W
38. A 115V AC, 400 Hz aircraft system has a load drawing 10A at 0.8 power factor. What is the
apparent power?
a) 920 VA
b) 1150 VA
c) 1437.5 VA
d) 1800 VA
Answer: b) 1150 VA
39. What is the inductance of a coil that has a reactance of 100 Ω at 400 Hz?
a) 39.8 mH
b) 79.6 mH
c) 159.2 mH
d) 318.3 mH
Answer: a) 39.8 mH
40. An aircraft generator rated at 30 kVA, 0.8 power factor is operating at full load. What is the
reactive power output?
a) 12 kVAR
b) 18 kVAR
c) 24 kVAR
d) 30 kVAR
Answer: b) 18 kVAR
41. What is the impedance of a parallel RLC circuit at resonance, if R = 100 Ω, L = 10 mH, and C = 1
μF?
a) 0 Ω
b) 50 Ω
c) 100 Ω
d) 200 Ω
Answer: c) 100 Ω
42. A 28V DC aircraft system has a 100 Ah battery. How long can it supply a constant 10A load?
a) 5 hours
b) 7 hours
c) 10 hours
d) 14 hours
Answer: c) 10 hours
43. What is the power factor of a circuit with 12 Ω resistance and 5 Ω inductive reactance?
a) 0.707
b) 0.8
c) 0.923
d) 0.96
Answer: c) 0.923
44. An aircraft electrical system has a total load of 40 kW at 0.9 power factor. What is the apparent
power?
a) 36 kVA
b) 40 kVA
c) 44.4 kVA
d) 50 kVA
Answer: c) 44.4 kVA
45. What is the capacitance needed to correct the power factor of a 10 kVA, 0.8 lagging load to unity
power factor in a 115V, 400 Hz system?
a) 129 μF
b) 258 μF
c) 387 μF
d) 516 μF
Answer: b) 258 μF
46. A 115V AC, 400 Hz aircraft system has a load with 5 Ω resistance and 12 Ω capacitive reactance.
What is the power factor?
a) 0.384
b) 0.5
c) 0.707
d) 0.866
Answer: a) 0.384
47. What is the efficiency of a transformer with 100W input power and 95W output power?
a) 90%
b) 93%
c) 95%
d) 97%
Answer: c) 95%
48. An aircraft electrical bus carries 50A at 115V AC. What is the minimum wire gauge (AWG)
required if the maximum allowed current density is 5 A/mm²?
a) 8 AWG
b) 10 AWG
c) 12 AWG
d) 14 AWG
Answer: b) 10 AWG
49. What is the total resistance of three 30 Ω resistors connected in parallel?
a) 5 Ω
b) 10 Ω
c) 15 Ω
d) 90 Ω
Answer: b) 10 Ω
50. A 400 Hz aircraft generator has 4 poles. What is its rotational speed in RPM?
a) 3000 RPM
b) 6000 RPM
c) 12000 RPM
d) 24000 RPM
Answer: b) 6000 RPM
51. What is the phase difference between line-to-line voltages in a balanced three-phase system?
a) 60°
b) 90°
c) 120°
d) 180°
Answer: c) 120°
A 115V AC, 400 Hz aircraft system has a 20 μF capacitor. What is its reactance?
a) 19.9 Ω
b) 39.8 Ω
c) 79.6 Ω
d) 159.2 Ω
Answer: a) 19.9 Ω
14. What is the current drawn by a 1 kW resistive load on a 28V DC aircraft system?
a) 17.86 A
b) 28 A
c) 35.71 A
d) 57.14 A
Answer: c) 35.71 A
15. In a 400 Hz AC system, what is the inductive reactance of a 100 mH inductor?
a) 25.13 Ω
b) 251.3 Ω
c) 2513 Ω
d) 25130 Ω
Answer: b) 251.3 Ω
16. A transformer in an aircraft electrical system has a turns ratio of 2:1. If the primary voltage is
230V, what is the secondary voltage?
a) 57.5V
b) 115V
c) 230V
d) 460V
Answer: b) 115V
17. What is the time constant of an RC circuit with R = 100 kΩ and C = 10 μF?
a) 0.1 ms
b) 1 ms
c) 10 ms
d) 100 ms
Answer: b) 1 ms
18. An aircraft electrical system has a total load of 50 kVA at 0.9 power factor. What is the reactive
power?
a) 21.8 kVAR
b) 24.2 kVAR
c) 45 kVAR
d) 50 kVAR
Answer: a) 21.8 kVAR
19. What is the efficiency of a generator that produces 30 kW of electrical power while consuming 35
kW of mechanical power?
a) 75%
b) 80%
c) 85.7%
d) 90%
Answer: c) 85.7%
20. A 115V AC, 400 Hz aircraft system has a load with 10 Ω resistance and 5 Ω inductive reactance.
What is the power factor?
a) 0.5
b) 0.707
c) 0.894
d) 1
Answer: c) 0.894
21. What is the phase angle between voltage and current in a circuit with 8 Ω resistance and 6 Ω
capacitive reactance?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
22. An aircraft battery has an internal resistance of 0.05 Ω and an open-circuit voltage of 24V. What is
the terminal voltage when supplying 100A?
a) 19V
b) 21V
c) 23V
d) 24V
Answer: b) 21V
23. What is the skin depth of copper at 400 Hz, given that ρ = 1.68 × 10^-8 Ω·m and μr = 1?
a) 0.33 mm
b) 3.3 mm
c) 33 mm
d) 330 mm
Answer: a) 0.33 mm
24. A 115V AC, 400 Hz aircraft generator has a synchronous reactance of 0.5 Ω. What is its short-
circuit current?
a) 115 A
b) 230 A
c) 460 A
d) 920 A
Answer: b) 230 A
25. What is the power dissipated in a 50 Ω resistor when 2A RMS flows through it?
a) 100 W
b) 141.4 W
c) 200 W
d) 282.8 W
Answer: c) 200 W
26. An aircraft electrical system uses a 3-phase, 115/200V, 400 Hz supply. What is the line current if
the total load is 30 kVA at unity power factor?
a) 50 A
b) 86.6 A
c) 100 A
d) 173.2 A
Answer: b) 86.6 A
27. What is the resonant frequency of an LC circuit with L = 1 mH and C = 10 μF?
a) 1.59 kHz
b) 15.9 kHz
c) 159 kHz
d) 1.59 MHz
Answer: b) 15.9 kHz
28. A 28V DC aircraft system has a cable with 0.01 Ω/m resistance. What is the voltage drop over
10m when carrying 50A?
a) 2.8V
b) 5V
c) 14V
d) 28V
Answer: b) 5V
29. What is the Q factor of an inductor with L = 10 mH and R = 2 Ω at 400 Hz?
a) 12.57
b) 25.13
c) 50.27
d) 100.53
Answer: b) 25.13
30. An aircraft generator produces 115V AC. What is the peak voltage?
a) 81.32V
b) 115V
c) 162.63V
d) 230V
Answer: c) 162.63V
31. What is the total capacitance of two 10 μF capacitors connected in series?
a) 2.5 μF
b) 5 μF
c) 10 μF
d) 20 μF
Answer: b) 5 μF
32. An aircraft electrical system has a power factor of 0.8 lagging. What is the phase angle between
voltage and current?
a) 36.87°
b) 45°
c) 53.13°
d) 60°
Answer: a) 36.87°
33. What is the RMS value of a 28V DC signal?
a) 19.8V
b) 28V
c) 39.6V
d) 56V
Answer: b) 28V
34. A 400 Hz transformer has 500 turns on the primary and 100 turns on the secondary. If the
primary voltage is 230V, what is the secondary voltage?
a) 23V
b) 46V
c) 115V
d) 1150V
Answer: b) 46V
35. What is the time constant of an RL circuit with R = 50 Ω and L = 100 mH?
a) 0.5 ms
b) 1 ms
c) 2 ms
d) 5 ms
Answer: c) 2 ms
36. An aircraft electrical system has a total impedance of 10 Ω at 30°. What is the resistance
component?
a) 5 Ω
b) 7.07 Ω
c) 8.66 Ω
d) 10 Ω
Answer: c) 8.66 Ω
37. What is the power dissipated in a 10 Ω resistor when 5V RMS is applied across it?
a) 1.25 W
b) 2.5 W
c) 5 W
d) 10 W
Answer: b) 2.5 W
38. A 115V AC, 400 Hz aircraft system has a load drawing 10A at 0.8 power factor. What is the
apparent power?
a) 920 VA
b) 1150 VA
c) 1437.5 VA
d) 1800 VA
Answer: b) 1150 VA
39. What is the inductance of a coil that has a reactance of 100 Ω at 400 Hz?
a) 39.8 mH
b) 79.6 mH
c) 159.2 mH
d) 318.3 mH
Answer: a) 39.8 mH
40. An aircraft generator rated at 30 kVA, 0.8 power factor is operating at full load. What is the
reactive power output?
a) 12 kVAR
b) 18 kVAR
c) 24 kVAR
d) 30 kVAR
Answer: b) 18 kVAR
41. What is the impedance of a parallel RLC circuit at resonance, if R = 100 Ω, L = 10 mH, and C = 1
μF?
a) 0 Ω
b) 50 Ω
c) 100 Ω
d) 200 Ω
Answer: c) 100 Ω
42. A 28V DC aircraft system has a 100 Ah battery. How long can it supply a constant 10A load?
a) 5 hours
b) 7 hours
c) 10 hours
d) 14 hours
Answer: c) 10 hours
43. What is the power factor of a circuit with 12 Ω resistance and 5 Ω inductive reactance?
a) 0.707
b) 0.8
c) 0.923
d) 0.96
Answer: c) 0.923
44. An aircraft electrical system has a total load of 40 kW at 0.9 power factor. What is the apparent
power?
a) 36 kVA
b) 40 kVA
c) 44.4 kVA
d) 50 kVA
Answer: c) 44.4 kVA
45. What is the capacitance needed to correct the power factor of a 10 kVA, 0.8 lagging load to unity
power factor in a 115V, 400 Hz system?
a) 129 μF
b) 258 μF
c) 387 μF
d) 516 μF
Answer: b) 258 μF
46. A 115V AC, 400 Hz aircraft system has a load with 5 Ω resistance and 12 Ω capacitive reactance.
What is the power factor?
a) 0.384
b) 0.5
c) 0.707
d) 0.866
Answer: a) 0.384
47. What is the efficiency of a transformer with 100W input power and 95W output power?
a) 90%
b) 93%
c) 95%
d) 97%
Answer: c) 95%
48. An aircraft electrical bus carries 50A at 115V AC. What is the minimum wire gauge (AWG)
required if the maximum allowed current density is 5 A/mm²?
a) 8 AWG
b) 10 AWG
c) 12 AWG
d) 14 AWG
Answer: b) 10 AWG
49. What is the total resistance of three 30 Ω resistors connected in parallel?
a) 5 Ω
b) 10 Ω
c) 15 Ω
d) 90 Ω
Answer: b) 10 Ω
50. A 400 Hz aircraft generator has 4 poles. What is its rotational speed in RPM?
a) 3000 RPM
b) 6000 RPM
c) 12000 RPM
d) 24000 RPM
Answer: b) 6000 RPM
51. What is the phase difference between line-to-line voltages in a balanced three-phase system?
a) 60°
b) 90°
c) 120°
d) 180°
Answer: c) 120°
52. An aircraft electrical system uses a 50 kVA transformer with 98% efficiency. What are the losses at
full load?
a) 500 W
b) 1000 W
