Whether you’re preparing for exams, interviews, or just want to brush up your knowledge, these 20 carefully selected multiple-choice questions (MCQs) cover a wide range of foundational electrical engineering topics including circuits, machines, power systems, and electronics.
1-Ohm’s Law states that:
A) Voltage = Current × Resistance
B) Voltage = Resistance / Current
C) Resistance = Power × Voltage
D) Current = Power × Resistance
✅ Answer: A
2-The unit of electrical capacitance is:
A) Ohm
B) Farad
C) Watt
D) Coulomb
✅ Answer: B
3-Which one is a passive component?
A) Transistor
B) Diode
C) Resistor
D) MOSFET
✅ Answer: C
4-A transformer operates on the principle of:
A) Static Induction
B) Mutual Induction
C) Electrostatic Induction
D) Self Induction
✅ Answer: B
5-Power factor is defined as:
A) True Power / Apparent Power
B) Apparent Power / True Power
C) Real Power × Reactive Power
D) Resistance / Reactance
✅ Answer: A
6-The frequency of the standard AC supply in most countries is:
A) 50 Hz or 60 Hz
B) 100 Hz
C) 25 Hz
D) 75 Hz
✅ Answer: A
7-Kirchhoff’s Voltage Law (KVL) is based on:
A) Conservation of charge
B) Conservation of energy
C) Faraday’s law
D) Coulomb’s law
✅ Answer: B
8-The most commonly used material for electrical wire conductors is:
A) Iron
B) Silver
C) Copper
D) Zinc
✅ Answer: C
9-In a DC motor, the commutator:
A) Increases speed
B) Converts DC to AC
C) Reverses current direction
D) Decreases torque
✅ Answer: C
10-A diode allows current to flow in:
A) No direction
B) Both directions
C) Only forward direction
D) Only reverse direction
✅ Answer: C
11-The ideal voltage source has:
A) Zero voltage
B) Infinite resistance
C) Zero internal resistance
D) Very high current
✅ Answer: C
12-The main function of a circuit breaker is to:
A) Increase voltage
B) Regulate frequency
C) Protect circuit from overload
D) Act as a switch
✅ Answer: C
13-Which instrument is used to measure current?
A) Voltmeter
B) Ammeter
C) Wattmeter
D) Ohmmeter
✅ Answer: B
14-An inductor stores energy in the form of:
A) Heat
B) Magnetic field
C) Electric field
D) Light
✅ Answer: B
15-Which law is used to determine the direction of induced current?
A) Faraday’s Law
B) Ohm’s Law
C) Lenz’s Law
D) Gauss’s Law
✅ Answer: C
16-RMS value of AC current is:
A) Maximum value × 0.5
B) Average value × 1.11
C) Peak value / √2
D) Peak value × √2
✅ Answer: C
17-Which device converts AC to DC?
A) Inverter
B) Rectifier
C) Transformer
D) Chopper
✅ Answer: B
18-A synchronous motor runs at:
A) Below synchronous speed
B) Varying speed
C) Synchronous speed
D) Above synchronous speed
✅ Answer: C
19-A fuse works on the principle of:
A) Magnetic effect
B) Electrostatic effect
C) Heating effect
D) Inductive effect
✅ Answer: C
20-The color code for a 1 kΩ resistor with 5% tolerance is:
A) Brown-Black-Red-Gold
B) Red-Black-Red-Silver
C) Orange-Orange-Brown-Gold
D) Brown-Black-Orange-Gold
✅ Answer: A
Final Words
These questions are excellent for interviews, competitive exams, and foundational understanding. Make sure to regularly practice MCQs to strengthen your concepts and spot knowledge gaps.
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