Electrical Engineering MCQs
Electrical Engineering MCQs are essential for aspirants preparing for engineering exams and job tests conducted by PPSC, FPSC, NTS, and other testing services. This section includes questions from power systems, basic electronics, circuit analysis, machines, measurements, and electromagnetism. Whether you're revising for an academic test or preparing for professional assessments, these multiple-choice questions are tailored to cover the entire Electrical Engineering syllabus. The content is designed to reflect current trends in competitive exams and industry requirements. Practicing these MCQs will help you strengthen your concepts, improve time management, and increase your chances of scoring high in electrical engineering exams in Pakistan.
Q: Power factor in an ideal purely resistive circuit is
A) Negative
B) Zero
C) One
D) Infinity
✅ Correct Answer: C
Explanation: In purely resistive circuits, voltage and current are in phase, so power factor is 1.
Q: Inductive reactance increases with
A) Increasing resistance
B) Decreasing frequency
C) Increasing frequency
D) Constant voltage
✅ Correct Answer: C
Explanation: Inductive reactance XL = 2πfL increases as frequency increases.
Q: A three-phase system is preferred over single-phase because it
A) Has less current
B) Provides constant power
C) Requires fewer wires
D) Is simpler
✅ Correct Answer: B
Explanation: Three-phase power is more efficient and provides constant power delivery.
Q: Current in a conductor is due to
A) Electron flow
B) Hole movement
C) Neutron movement
D) Proton flow
✅ Correct Answer: A
Explanation: Free electrons are responsible for current in conductors.
Q: Power in a resistive circuit is calculated as
A) V/I
B) VI
C) V^2/I
D) I^2/R
✅ Correct Answer: B
Explanation: Power is voltage multiplied by current: P = VI.
Q: The RMS value of AC current is
A) Double peak
B) 0.5 of peak
C) 0.707 of peak
D) Equal to peak
✅ Correct Answer: C
Explanation: RMS (Root Mean Square) value is 0.707 × peak value for sine wave AC.
Q: A fuse protects against
A) Reverse polarity
B) Under voltage
C) Overcurrent
D) High power factor
✅ Correct Answer: C
Explanation: Fuses break the circuit when excessive current flows.
Q: A zener diode is mainly used for
A) Switching
B) Rectification
C) Current amplification
D) Voltage regulation
✅ Correct Answer: D
Explanation: Zener diodes regulate voltage in circuits.
Q: Inductors oppose changes in
A) Current
B) Resistance
C) Frequency
D) Voltage
✅ Correct Answer: A
Explanation: Inductors resist changes in current due to their magnetic field.
Q: Alternating current changes direction
A) Constantly
B) Never
C) Once per second
D) Randomly
✅ Correct Answer: A
Explanation: AC alternates direction periodically based on its frequency.