The materials suitable for making electromagnets should have

The magnetic susceptibility of the material of a rod is 349 and permeability of vacuum $$\mu_0$$ is $$4 \pi \times 10^{-7}$$ SI units. Absolute permeability of the material of the rod in SI units is

Two bar magnets '$$\mathrm{P}$$' and '$$\mathrm{Q}$$' are kept in uniform magnetic field '$$\mathrm{B}$$' with magnetic moments '$$\mathrm{M_P}$$' and '$$\mathrm{M_Q}$$' respectively. Magnet 'P' is oscillating with frequency twice that of magnet 'Q'. If the moment of inertia of the magnet 'P' is twice that of magnet 'Q' then

A magnetic dipole of magnetic moment $$\mathrm{M}$$, is freely suspended in a magnetic field of induction B. The minimum and maximum values of potential energy of the dipole, respectively are