Electrical Engineering MCQ’s

1. What is the unit of electrical current?

A) Volt
B) Ampere
C) Ohm
D) Watt

2. Which of the following is a passive component?

A) Resistor
B) Transistor
C) Diode
D) Operational Amplifier

3. What does Ohm’s Law state?

A) V = I/R
B) V = IR
C) P = IV
D) R = VI

4. In a series circuit, the total resistance is:

A) The sum of the individual resistances
B) The product of the individual resistances
C) The average of the individual resistances
D) Zero

5. What is the purpose of a capacitor in a circuit?

A) To store energy
B) To amplify signals
C) To convert AC to DC
D) To limit current

6. Which instrument is used to measure voltage?

A) Ammeter
B) Voltmeter
C) Ohmmeter
D) Wattmeter

7. What type of wave does an AC supply produce?

A) Square wave
B) Triangular wave
C) Sine wave
D) Sawtooth wave

8. What is the function of a transformer?

A) To store electrical energy
B) To convert AC voltage levels
C) To convert DC to AC
D) To measure current

9. The frequency of a 60 Hz AC supply is:

A) 10 seconds
B) 60 seconds
C) 1/60 seconds
D) 60 cycles per second

10. What does the term “ground” refer to in electrical systems?

A) A type of wire
B) A connection to the earth
C) A type of capacitor
D) A resistor’s neutral point

11. Which of the following is a characteristic of a diode?

A) It allows current to flow in both directions
B) It allows current to flow in only one direction
C) It stores electrical charge
D) It generates electricity

12. In a parallel circuit, the voltage across each component is:

A) Different
B) The same
C) Zero
D) Half of the source voltage

13. What does a fuse do in an electrical circuit?

A) Stores electrical energy
B) Breaks the circuit when current exceeds a safe level
C) Amplifies the current
D) Measures voltage

14. What is the typical range of household voltage in most countries?

A) 5V
B) 12V
C) 120V – 240V
D) 1000V

15. Which device is used to convert AC to DC?

A) Inductor
B) Capacitor
C) Rectifier
D) Transformer

16. What is the primary purpose of an inductor?

A) To resist current
B) To store energy in a magnetic field
C) To convert voltage
D) To filter signals

17. The power factor of a purely resistive circuit is:

A) 0
B) 0.5
C) 1
D) Infinity

18. What does PWM stand for in electrical engineering?

A) Pulse Width Modulation
B) Power Wave Modulation
C) Phase Width Measurement
D) Pulse Wave Measurement

19. Which law states that the total current entering a junction equals the total current leaving?

A) Kirchhoff’s Voltage Law
B) Ohm’s Law
C) Kirchhoff’s Current Law
D) Faraday’s Law

20. What is the purpose of an electrical circuit breaker?

A) To store electrical energy
B) To interrupt the circuit in case of overload
C) To convert AC to DC
D) To amplify signals

21. What is the main function of a relay?

A) To amplify voltage
B) To switch a circuit on or off
C) To measure current
D) To store energy

22. Which type of motor is commonly used in home appliances?

A) Synchronous Motor
B) Induction Motor
C) DC Motor
D) Stepper Motor

23. What is the purpose of a voltage regulator?

A) To increase voltage
B) To stabilize voltage
C) To decrease voltage
D) To measure voltage

24. What is a common cause of electrical shock?

A) Short circuit
B) Ground fault
C) Overvoltage
D) All of the above

25. What is the typical efficiency range of electric motors?

A) 50% – 60%
B) 70% – 80%
C) 80% – 90%
D) 90% – 95%