Magnetism and Matter

A bar magnet has magnetic moment of $0.05 \mathrm{Am}^2$ which is suspended in uniform magnetic field of 0.2 T . Calculate the work done in rotating the magnet from its most stable to most unstable position in the magnetic field.

Magnetic moment of bar magnet is \(2 M\). The work done to turn the magnet by \(90^{\circ}\) of magnet in direction of magnetic field \(B / 2\) will be

If the B - H curves of two samples of X and Y of iron are as shown below, then which one of the following statement is correct?

A long cylindrical iron core of cross-sectional area 5 cm2 is inserted into a long solenoid having 4000 turns/meter and carrying a current 5 A. The magnetic field inside the core is \(\pi\) T. Find the pole strength developed.