Electromagnetic Induction MCQ Quiz - Multiple Choice Questions & Answers Page 2

11. Lenz's law is a consequence of the law of conservation of

1. charge
2. mass
3. energy
4. momentum

12. A magnet is moved towards a coil (i) quickly (ii) slowly, then the induced e.m.f. is

1. larger in case (i)
2. smaller in case (i)
3. equal to both the cases
4. larger or smaller depending upon the radius of the coil

13. The laws of electromagnetic induction have been used in the construction of a

1. galvanometer
2. voltmeter
3. electric motor
4. generator

14. Two coils are placed closed to each other. The mutual inductance of the pair of coils depends upon

1. the rate at which currents are changing in the two coils.
2. relative position and orientation of two coils.
3. the material of the wires of the coils.
4. the currents in the two coils.

15. Two identical coaxial circular loops carry a current i each circulating in the same direction. If the loops approach each other, you will observe that the current in

1. each increases
2. each decreases
3. each remains the same
4. one increases whereas that in the other decreases

16. When current in a coil changes from 5 A to 2 A in 0.1 s, average voltage of 50 V is produced. The self-inductance of the coil is

1. 1.67 H
2. 6 H
3. 3 H
4. 0.67 H

17. The self inductance associated with a coil is independent of

1. current
2. induced voltage
3. time
4. resistance of a coil

18. A coil having 500 sq. loops of side 10 cm is placed normal to magnetic flux which increases at a rate of 1 T/s. The induced emf is

1. 0.1 V
2. 0.5 V
3. 1 V
4. 5 V

19. A coil of 100 turns carries a current of 5 mA and creates a magnetic flux of 10-5 weber. The inductance is

1. 0.2 mH
2. 2.0 mH
3. 0.02 mH
4. 0.002 H

20. The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a short galvanometer. The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was

1. moving towards the solenoid
2. moving into the solenoid
3. at rest inside the solenoid
4. moving out of the solenoid