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

• A. Loop assumes a circular shape with its plane parallel to field
• B. Shape of the loop remains unchanged
• C. Wire gets stretched to become straight
• D. Loop assumes circular shape with its plane normal to the field

Answer 1

The correct option is D

Loop assumes circular shape with its plane normal to the field

Correct option is D: Loop assumes circular shape with its plane normal to the field

Explanation for the correct option and drawing the diagram

1. When A loop of flexible wire of irregular shape carrying current is placed in an external magnetic field, it will definitely experience the force.
2. The magnetic force is always perpendicular to the direction of magnetic field.
3. Suppose external magnetic field is in inward direction, perpendicular to the loop then force on the loop will try to reform it into the circular shape with its plane normal to the magnetic field.

Hence, option (D) is correct.