Electrical PE Exam Practice Questions –
2026 Edition | Ace Your Exam with
Instant PDF
1. A 3-phase, 60 Hz, 480 V (line-to-line) wye-connected system has a
balanced load of 10 kVA per phase with a power factor of 0.8 lagging.
What is the line current?
A) 12.5 A
B) 15.1 A
C) 12.0 A
D) 14.5 A
Rationale: Line current in a wye system is I_L = S_phase / (√3 × V_L-L)
= 10,000 / (√3 × 480 × 0.8) ≈ 12.0 A
2. Which device is used to protect transformers from overcurrent
conditions?
A) Surge arrester
B) Circuit breaker
C) Voltage regulator
D) Tap changer
Rationale: Circuit breakers are designed to interrupt overcurrent
conditions, protecting transformers and other equipment from
damage.
,3. For a purely inductive AC circuit, which statement is true?
A) Voltage and current are in phase
B) Current lags voltage by 90°
C) Current leads voltage by 90°
D) Voltage lags current by 45°
Rationale: In a purely inductive circuit, the inductor opposes changes
in current, causing the current to lag the voltage by 90°.
4. A single-phase, 120 V, 60 Hz resistive heater draws 10 A. What is
the power consumed?
A) 1200 W
B) 1200 W
C) 1000 W
D) 600 W
Rationale: Power for a resistive load is P = V × I = 120 × 10 = 1200 W.
5. In a transmission line, the primary purpose of a capacitor bank is to:
A) Step down voltage
B) Limit fault current
C) Improve power factor
D) Protect against surges
Rationale: Capacitor banks supply reactive power, which improves the
power factor of the system.
,6. The main function of a step-up transformer in a power system is to:
A) Increase current for distribution
B) Increase voltage for transmission
C) Reduce voltage for utilization
D) Provide overcurrent protection
Rationale: Step-up transformers increase voltage to reduce I²R losses
in long-distance transmission.
7. Which of the following is a characteristic of a synchronous motor?
A) Operates only at lagging power factor
B) Speed varies with load
C) Operates at constant speed
D) Cannot be used for power factor correction
Rationale: Synchronous motors run at constant speed determined by
supply frequency and number of poles.
8. A 240 V AC motor has a starting current of 30 A and a running
current of 10 A. Which device is appropriate for starting?
A) Direct-on-line starter
B) Star-delta starter
C) Fused disconnect
D) Voltage regulator
, Rationale: Star-delta starters reduce starting current to prevent
excessive mechanical and electrical stress on the motor.
9. Which of the following is the unit of magnetic flux?
A) Tesla
B) Ampere
C) Henry
D) Weber
Rationale: Magnetic flux is measured in Webers (Wb), representing
the total magnetic field passing through a surface.
10. In a three-phase system, if the load is balanced and wye-
connected, the line voltage is:
A) Equal to phase voltage
B) √3 times the phase voltage
C) Half the phase voltage
D) Twice the phase voltage
Rationale: For a balanced wye system, V_L = √3 × V_phase.
11. A 480 V, 3-phase induction motor has an efficiency of 90% and
draws 50 A at full load. What is the output power?
A) 37.4 kW
B) 37.4 kW
2026 Edition | Ace Your Exam with
Instant PDF
1. A 3-phase, 60 Hz, 480 V (line-to-line) wye-connected system has a
balanced load of 10 kVA per phase with a power factor of 0.8 lagging.
What is the line current?
A) 12.5 A
B) 15.1 A
C) 12.0 A
D) 14.5 A
Rationale: Line current in a wye system is I_L = S_phase / (√3 × V_L-L)
= 10,000 / (√3 × 480 × 0.8) ≈ 12.0 A
2. Which device is used to protect transformers from overcurrent
conditions?
A) Surge arrester
B) Circuit breaker
C) Voltage regulator
D) Tap changer
Rationale: Circuit breakers are designed to interrupt overcurrent
conditions, protecting transformers and other equipment from
damage.
,3. For a purely inductive AC circuit, which statement is true?
A) Voltage and current are in phase
B) Current lags voltage by 90°
C) Current leads voltage by 90°
D) Voltage lags current by 45°
Rationale: In a purely inductive circuit, the inductor opposes changes
in current, causing the current to lag the voltage by 90°.
4. A single-phase, 120 V, 60 Hz resistive heater draws 10 A. What is
the power consumed?
A) 1200 W
B) 1200 W
C) 1000 W
D) 600 W
Rationale: Power for a resistive load is P = V × I = 120 × 10 = 1200 W.
5. In a transmission line, the primary purpose of a capacitor bank is to:
A) Step down voltage
B) Limit fault current
C) Improve power factor
D) Protect against surges
Rationale: Capacitor banks supply reactive power, which improves the
power factor of the system.
,6. The main function of a step-up transformer in a power system is to:
A) Increase current for distribution
B) Increase voltage for transmission
C) Reduce voltage for utilization
D) Provide overcurrent protection
Rationale: Step-up transformers increase voltage to reduce I²R losses
in long-distance transmission.
7. Which of the following is a characteristic of a synchronous motor?
A) Operates only at lagging power factor
B) Speed varies with load
C) Operates at constant speed
D) Cannot be used for power factor correction
Rationale: Synchronous motors run at constant speed determined by
supply frequency and number of poles.
8. A 240 V AC motor has a starting current of 30 A and a running
current of 10 A. Which device is appropriate for starting?
A) Direct-on-line starter
B) Star-delta starter
C) Fused disconnect
D) Voltage regulator
, Rationale: Star-delta starters reduce starting current to prevent
excessive mechanical and electrical stress on the motor.
9. Which of the following is the unit of magnetic flux?
A) Tesla
B) Ampere
C) Henry
D) Weber
Rationale: Magnetic flux is measured in Webers (Wb), representing
the total magnetic field passing through a surface.
10. In a three-phase system, if the load is balanced and wye-
connected, the line voltage is:
A) Equal to phase voltage
B) √3 times the phase voltage
C) Half the phase voltage
D) Twice the phase voltage
Rationale: For a balanced wye system, V_L = √3 × V_phase.
11. A 480 V, 3-phase induction motor has an efficiency of 90% and
draws 50 A at full load. What is the output power?
A) 37.4 kW
B) 37.4 kW
