Question

If the work done in turning a magnet of magnetic moment \( M \) by an angle of \( 90^\circ \) from the magnetic meridian is in times the corresponding work done to turn it through an angle of \( 60^\circ \), then the value of \( n \) is

• A. \( 1 \)
• B. \( 1/2 \)
• C. \( 2 \)
• D. \( 1/4 \)

Hint:

The work done to rotate a magnet in a magnetic field is proportional to the angle of rotation and the magnetic moment.

Answer 1

The Correct Option is B

Step 1: Work done in rotating a magnet.
The work done in rotating a magnet is given by \( W = M \cdot B \cdot \theta \). The ratio of work done in rotating by \( 90^\circ \) and \( 60^\circ \) gives the value of \( n \).

Step 2: Conclusion.
The value of \( n \) is \( 1/2 \), corresponding to option (2).