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Electromagnetic Induction MCQ Test

Class 12 Physics - Section A

Instructions: This test contains 20 multiple-choice questions. Select the best answer for each question. After completing all questions, click "Submit Answers" to see your score and feedback.

Time: Approximately 30 minutes

1. Who discovered electromagnetic induction?

James Clerk Maxwell

Michael Faraday

Heinrich Lenz

André-Marie Ampère

2. According to Faraday's law, the induced emf in a circuit is directly proportional to:

The magnetic field strength

The area of the loop

The rate of change of magnetic flux

The resistance of the circuit

3. Lenz's law is a consequence of the law of conservation of:

Energy

Charge

Momentum

Angular momentum

4. The SI unit of magnetic flux is:

Tesla

Weber

Henry

Farad

5. The phenomenon of producing an induced emf in a circuit due to change in current in the same circuit is called:

Mutual induction

Self induction

Electromagnetic induction

Eddy current

6. The direction of induced current is such that it opposes the change which has produced it. This is the statement of:

Faraday's law

Lenz's law

Ampere's law

Ohm's law

7. The SI unit of self-inductance is:

Weber

Tesla

Henry

Farad

8. A metal plate is allowed to swing between the poles of a strong magnet. The plate will:

Come to rest quickly

Keep swinging without any change

Get strongly attracted to one pole

Start rotating

9. The magnetic flux through a coil is given by Φ = (2t² + 3t + 5) Wb. The magnitude of induced emf at t = 2s is:

4 V

7 V

11 V

15 V

10. A rectangular loop of area A is placed in a uniform magnetic field B. The flux through the loop is maximum when the angle between the field and normal to the loop is:

0°

45°

90°

180°

11. The induced emf in a coil of 200 turns is 5 V. The rate of change of flux through the coil is:

0.025 Wb/s

0.25 Wb/s

2.5 Wb/s

25 Wb/s

12. A conducting rod of length l moves with velocity v perpendicular to a uniform magnetic field B. The induced emf across the rod is:

B²lv

Blv

Bl/v

Bv/l

13. The time constant of an L-R circuit is given by:

L/R

R/L

LR

1/LR

14. The energy stored in an inductor of inductance L carrying current I is:

(1/2)LI²

LI²

(1/2)L²I

(1/2)LI

15. In a transformer, the core is laminated to reduce:

Hysteresis loss

Eddy current loss

Copper loss

Flux leakage

16. Two coils have mutual inductance of 1.5 H. If the current in the primary changes from 0 to 10 A in 0.2 s, the induced emf in the secondary is:

7.5 V

15 V

75 V

150 V

17. The self-inductance of a solenoid depends on:

Number of turns

Area of cross-section

Length of solenoid

All of the above

18. Which of the following does not involve electromagnetic induction?

Transformer

AC generator

DC motor

Moving coil galvanometer

19. A metal ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet is:

Equal to g

Less than g

More than g

Zero

20. The coefficient of mutual induction between two coils depends on:

Relative position and orientation of the coils

Number of turns in each coil

Geometry of the coils

All of the above

Your Score: 0/20

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