Question

A square coil ABCD with its plane vertical is released from rest in a horizontal uniform magnetic field `vec"B"` of length 2L. The acceleration of the coil is ______.

Options

• less than g for all the time till the loop crosses the magnetic field completely.

• less than g when it enters the field and greater than g when it comes out of the field.

• g all the time

• less than g when it enters and comes out of the field but equal to g when it is within the field.

Answer 1

A square coil ABCD with its plane vertical is released from rest in a horizontal uniform magnetic field `vec"B"` of length 2L. The acceleration of the coil is less than g when it enters and comes out of the field but equal to g when it is within the field.

Explanation:

There is no change in magnetic flux passing through the coil when it is within the field. As a result, no current is induced, and the acceleration is g. However, Lenz's law states that the induced current will oppose its motion when it enters or exits the field. As a result, the acceleration will be less than g when it enters and exits the magnetic field.