# sir please show the derivation for toque acting on bar magnet in non unicorm magnetic filed.

Apoorva Arora IIT Roorkee
8 years ago
The torque acting on a bar magnet in a non-uniform magnetic field is the same as for that of a uniform magnetic field. This can be explained by taking an example of a current carrying loop.
the torque is given by
$\tau =iabB sin\theta$
ab is the area of the loop;
$\tau =iAsin\theta$
also $\mu = iA$ which is the magnetic moment which can be easily calculated for a bar magnet.
hence,
$\tau =\mu Bsin\theta$
$\tau =\mu\times B$
Thanks and Regards
Apoorva Arora
IIT Roorkee