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. 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

3. Eddy currents do not cause

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

5. A choke is used as a resistance in :

6. 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:

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

8. 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:

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

10. 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:

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

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

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

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

15. A metal plate can be heated by

16. 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 :

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

19. 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?

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