Question

A negative charge is given to a nonconducting loop and the loop is rotated in the plane of paper about its centre as shown in figure. The magnetic field produced by the ring affects a small magnet placed above the ring in the same plane, then which of the options is correct?

• A. The magnet does not rotate
• B. The magnet rotates clockwise as seen from below
• C. The magnet rotates anticlockwise as seen from below
• D. No effect on magnet is there

Answer 1

The correct option is B The magnet rotates clockwise as seen from below


The loop is rotated in clockwise direction, so current flows in anticlockwise direction. So the forces on the poles are as shown, and hence magnet rotates clockwise as seen from below.