A bar magnet of magnetic moment 6 is aligned at with a uniform external magnetic field of . Calculate (a) the work done in turning the magnet to align its magnetic moment (i) normal to the magnetic field,(ii) opposite to the magnetic field, and (b) the torque on the magnet in the final orientation in case (ii).
Given,
Magnetic moment
Magnetic field
The angle between the Bar magnet and magnet field
a)
Work done
i) normal to the magnetic field, then
Therefore,
ii) Opposite to the magnetic field the
Therefore,
b) torque is given as,
in this orientation the angle between moment and magnetic field
Therefore torque will be Zero