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

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

ab is the area of the loop;

also which is the magnetic moment which can be easily calculated for a bar magnet.
hence,


Thanks and Regards
Apoorva Arora
IIT Roorkee
askIITians Faculty