The magnetic susceptibility is negative for

A rectangular coil of length 0.12 m and width 0.1 m having 50 turns of wire is suspended vertically in a uniform magnetic field of strength 0.2 weber/m². The coil carries a current of 2 A. If the plane of the coil is inclined at an angle of 30^o with the direction of the field, the torque required to keep the coil in stable equilibrium will be

Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole moment $$\overrightarrow m .$$ Which configuration has highest net magnetic dipole moment ?

A bar magnet of magnetic moment M is placed at right angles to a magnetic induction B. If a force F is experienced by each pole of the magnet, the length of the magnet will be