A bar magnet of magnetic moment is suspended by a wire in a magnetic field. The upper end of the wire is rotated through , then the magnet rotated through .under similar conditions another magnet of magnetic moment is rotated through . Then find the ratio of and
A magnet of moment is suspended in the magnetic meridian with an un twisted wire.
The upper end of the wire is rotated through an angle to deflect the magnet by an angle from magnetic meridian. Then deflecting couple acting on the magnet =
Restoring couple developed in suspension wire =
C is the couple per unit twist of suspension wire.
In equilibrium position,
Given
for first magnet
for second magnet