Electromagnetic Induction Class 12 MCQs Questions with Answers

1. A solenoid is connected to a battery so that a steady current flows through it. If an iron core is inserted into the solenoid, the current will

2. Induced e.m.f. produced in a coil rotating in a magnetic field will be maximum when the angle between the axis of coil and direction of magnetic field is:

3. Eddy currents do not cause

4. Faraday’s laws are consequence of the conservation of

5. A metal conductor of length 1 m rotates vertically about one of its ends at angular velocity 5 rad s-1 . If the horizontal component of earth’s magnetism is 2 × 10-5 T, then e.m.f. developed between the two ends of the conductor is:

6. Direction of current induced in a wire moving in a magnetic field is found using

7. Two inductors of inductance .L each are connected in series with opposite? magnetic fluxes. The resultant inductance is (Ignore mutual inductance)

8. A metal plate can be heated by

9. Which of the following is based on the law of conservation of energy?

10. Which of the following is/are equal to Henry?

11. There is a uniform magnetic field directed perpendicular and into the plane of the paper. An irregular shaped conducting loop is slowly changing into a circular loop in the plane of the paper. Then

12. When the magnetic field is parallel to a surface, then the magnetic flux through the surface is:

13. A transformer is used to light 100 W and 110 V lamp from a 220 V mains. If the main current is 0.5 A. Then the efficiency of the transformer is:

14. The north pole of a bar magnet is rapidly introduced into a solenoid at one end (say A). Which of the following statements correctly depicts the phenomenon taking place?

15. The coupling co-efficient of the perfectly coupled coils is:

16. When the rate of change in current is unity, the induced emf is equal to

17. An e.m.f is produced in a coil, which is not connected to an external voltage source. This is not due to

18. Faraday’s laws are consequence of the conservation of

19. Two coils of self inductance 2 mil and 8 mil are placed so close together that the effective flux in one coil is completely linked with other. The mutual inductance between these coils is :

20. A choke is used as a resistance in :