Question

A cylindrical bar magnet is kept along the axis of a circular coil. If the magnet is rotated about its axis, then

• A. A current will be induced in a coil
• B. no current will be induced in a coil
• C. Only an e.m.f. will be induced in the coil
• D. An e.m.f. and a current both will be induced in the coil

Answer 1

The correct option is B

no current will be induced in a coil

Explanation for correct answer:

In case of option B:

1. In a coil emf induced when magnetic flux through it changes.
2. When bar magnet is rotated about its axis then magnetic flux through coil is constant.
3. This, no current will induced.

Explanation for the incorrect answers:

In case of option A :

1. Since, there is no emf induced.
2. Thus no current will induced.

In case of option C:

1. Flux through coil is constant.
2. Thus, no emf will induced.

In case of option D:

1. Magnetic flux through coil is constant.
2. Therefore, no current and emf will induced.

Hence, option B is the correct answer.