Explore topic-wise MCQs in Electrical Engineering.

This section includes 109 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.

1.

Calculate the emf induced in an inductor if the inductance is 10H and the current is 2A in 4s.

A. 2.5V
B. 1.5V
C. 3.5V
D. 5V
Answer» E.
2.

Find the coupling coefficient if the Mutual inductance is 20H, the inductance of coil 1 is 2H and the inductance of coil 2 is 8H.

A. 5
B. 20
C. 2
D. 8
Answer» B. 20
3.

In an RL series circuit, when the switch is closed and the circuit is complete, what is the response?

A. Response does not vary with time
B. Decays with time
C. Increases with time
D. First increases, then decrease
Answer» C. Increases with time
4.

A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the initial value of the voltage across the inductor.

A. 5V
B. 10V
C. 0 V
D. 20V
Answer» E.
5.

Which, among the following, is the correct formula to find the coupling coefficient?

A. k=M/sqrt(L1L2)
B. k=M/sqrt(L1²)
C. k=M/sqrt(L2²)
D. k=M/(L1L2)
Answer» B. k=M/sqrt(L1²)
6.

A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the value of current 1s after the switch is closed.

A. 5.44A
B. 4.32A
C. 6.56A
D. 2.34A
Answer» C. 6.56A
7.

The charging time constant of a circuit consisting of an inductor is the time taken for the current in the inductor to become __________% of the initial current.

A. 33
B. 63
C. 37
D. 36
Answer» C. 37
8.

If the flux linkage in coil 1 is 3Wb and it has 500 turns and the current in coil 2 is 2A, calculate the mutual inductance.

A. 750H
B. 500H
C. 450H
D. 900H
Answer» B. 500H
9.

Mutual inductance between two coupled coils depend on?

A. Amount of flux linkage
B. Rate of change of flux linkage
C. Rate of change of current
D. Flux density
Answer» C. Rate of change of current
10.

Find the time taken for the current in an inductor to change to 2A from 0A if the power in the inductor is 5W. The value of inductance is 10H.

A. 1s
B. 2s
C. 3s
D. 4s
Answer» E.
11.

Find the value of x if the Mutual inductance is x H, the inductance of coil 1 is 2H and the inductance of coil 2 is 8H. The coupling coefficient is 5.

A. 10H
B. 20H
C. 16H
D. 15H
Answer» C. 16H
12.

What is the SI unit of coupling coefficient?

A. H
B. H¯¹
C. No unit
D.
Answer» D. H²
13.

Calculate the resistance in an inductive circuit whose time constant is 2s and the inductance is 10H.

A. 7ohm
B. 10ohm
C. 2ohm
D. 5ohm
Answer» E.
14.

Which, among the following, is the correct expression for mutual inductance?

A. M=N2φ2/I2
B. M=N2φ2/I1
C. M=N1φ2/I2
D. M=N1φ1/I1
Answer» C. M=N1φ2/I2
15.

Calculate the power in an inductive circuit if the inductance is 10H, the current flowing in the inductor is 2A in 4s.

A. 50W
B. 4W
C. 5W
D. 10W
Answer» D. 10W
16.

A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the final value of the voltage across the inductor.

A. 5V
B. 10V
C. 0 V
D. 20V
Answer» D. 20V
17.

The types of inductors are ____________

A. Fixed and variable
B. Only fixed
C. Only variable
D. Neither fixed nor variable
Answer» B. Only fixed
18.

What is the total applied voltage in an inductive circuit?

A. V=Ri+Ldi/dt
B. V=Ri+di/dt
C. V=i+Ldi/dt
D. V=R+Ldi/dt
Answer» B. V=Ri+di/dt
19.

Find the value of x if the Mutual inductance is 20H, the inductance of coil 1 is xH and the inductance of coil 2 is 8H. The coupling coefficient is 5.

A. 2H
B. 4H
C. 6H
D. 8H
Answer» B. 4H
20.

Calculate the inductance in an inductive circuit whose time constant is 2s and the resistance is 5 ohm.

A. 10H
B. 20H
C. 5H
D. 15H
Answer» B. 20H
21.

Calculate the value of stored energy in an inductor if the value of inductance is 20H and 4A of current flows through it.

A. 220J
B. 150J
C. 190J
D. 160J
Answer» E.
22.

For a coil having a magnetic circuit of constant reluctance, the flux is ___________ to the current.

A. Directly proportional
B. Inversely proportional
C. Not related
D. Very large compared to
Answer» B. Inversely proportional
23.

An induced emf is said to be ________

A. Inductive
B. Capacitive
C. Resistive
D. Cannot be determined
Answer» B. Capacitive
24.

If the resistance in a circuit is 2 ohm and the impedance is 20 ohm, calculate the power factor.

A. 1/10
B. 1/20
C. 1/30
D. 1/40
Answer» B. 1/20
25.

What is the time constant of an inductive circuit?

A. LR
B. R/L
C. 1/LR
D. L/R
Answer» E.
26.

If the current changes from 5A to 3A in x sec and inductance is 10H. The emf is 10V, calculate the value of x.

A. 2s
B. 3s
C. 4s
D. 5s
Answer» B. 3s
27.

Find the average current in an inductor if the total current in the inductor is 26A.

A. 10A
B. 26A
C. 13A
D. 5A
Answer» D. 5A
28.

If the current in one coil is steady, what happens to the mutual inductance?

A. Zero
B. Infinity
C. Doubles
D. Halves
Answer» B. Infinity
29.

What is the SI unit of mutual inductance?

A. Ohm
B. Henry
C. Volt
D. Siemens
Answer» C. Volt
30.

If the current in one coil becomes steady, the current in neighbouring coil is?

A. Zero
B. Infinity
C. Doubles
D. Halves
Answer» B. Infinity
31.

For a coil having a magnetic circuit of constant reluctance, if the flux increases, what happens to the current?

A. Increases
B. Decreases
C. Remains constant
D. Becomes zero
Answer» B. Decreases
32.

If the current in a coil having a constant inductance of L henrys grows at a uniform rate, what is the value of the average current?

A. I
B. I/2
C. I/4
D. 0
Answer» C. I/4
33.

The flux linkage in coil 1 is x and it has 500 turns and the current in coil 2 is 2A, calculate the value of x if the mutual inductance is 750H.

A. 1Wb
B. 2Wb
C. 3Wb
D. 4Wb
Answer» D. 4Wb
34.

Calculate the current in an inductor if the energy stored is 160J and the inductance is 20H.

A. 1A
B. 2A
C. 3A
D. 4A
Answer» E.
35.

What happens to the inductance when the current in the coil becomes double its original value?

A. Becomes half
B. Becomes four times
C. Becomes double
D. Remains same
Answer» E.
36.

If the current changes from 3A to 5A in 2s and the emf is 10V. Calculate the inductance.

A. 10H
B. 20H
C. 30H
D. 40H
Answer» B. 20H
37.

Find voltage across 20H inductor.

A. 2V
B. 10V
C. 12V
D. 20V
Answer» E.
38.

Find voltage across 12H inductor.

A. 2V
B. 10V
C. 12V
D. 20V
Answer» D. 20V
39.

What is the expression for voltage in the given circuit?

A. a
B. b
C. c
D. d
Answer» D. d
40.

Calculate the equivalent inductance between A and B.

A. 30H
B. 54H
C. 44H
D. 60H
Answer» D. 60H
41.

Find voltage across 10H inductor.

A. 2V
B. 10V
C. 12V
D. 20V
Answer» C. 12V
42.

What is the relation between the flux and the magnetizing current when a ferromagnetic core is introduced within the inductor?

A. Directly proportional
B. Inversely proportional
C. Not proportional
D. Current is double of flux
Answer» D. Current is double of flux
43.

Calculate the change in current in an inductor having inductance 4000H, number of turns is 200 and the flux changes from 760 to 800 Wb.

A. 2A
B. 4A
C. 6A
D. 8A
Answer» B. 4A
44.

Calculate the time constant of an inductive circuit having resistance 5 ohm and inductance 10H.

A. 2s
B. 4s
C. 5s
D. 0s
Answer» B. 4s
45.

What happens to the effective inductance when a ferromagnetic core is introduced?

A. Increases
B. Decreases
C. Remains the same
D. Becomes zero
Answer» B. Decreases
46.

Calculate the value of emf in an inductor if the value of inductance is 15H and an average current of 5A flows through it in 10s.

A. 15V
B. 7.5V
C. 10V
D. 5.5V
Answer» C. 10V
47.

What is the energy stored in the magnetic field if the current in a coil has a constant inductance of L henrys grows at a uniform rate?

A. LI/2
B. LI²/2
C. L/2I
D. L/2I²
Answer» C. L/2I
48.

A coil has a resistance of 4 ohms and an inductance of 2H. It is connected to a 20V dc supply. Calculate the value of voltage 1s after the switch is closed.

A. 5.4V
B. 10.8V
C. 0 V
D. 2.7V
Answer» E.
49.

If either the inductance or the rate of change of current is doubled, the induced e.m.f?

A. Remains constant
B. Becomes zero
C. Doubles
D. Becomes half
Answer» D. Becomes half
50.

Initially, when the switch in a series RL circuit is closed, the inductor acts as?

A. Open circuit
B. Short circuit
C. Resistor
D. Capacitor
Answer» B. Short circuit