# A loop of flexible wire of irregular shape carrying current is placed in an external magnetic field.

Question:

A loop of flexible wire of irregular shape carrying current is placed in an external magnetic field. Identify the effect of the field on the wire.

1. (1) Loop assumes circular shape with its plane normal to the field.

2. (2) Loop assumes circular shape with its plane parallel to the field.

3. (3) Wire gets stretched to become straight.

4. (4) Shape of the loop remains unchanged.

Correct Option: 1

Solution:

(1)

Every part ( $\mathrm{d} \ell$ ) of the wire is pulled by force $\mathrm{i}(\mathrm{d} \ell) \mathrm{B}$ acting perpendicular to current \& magnetic field giving it a shape of circle.