^Superconductors: Perfect diamagnetics

Superconductors: Perfect diamagnetics

For super conductors cooled to very low temperatures χ = –1 & μ_r = 0.

Thus the super conductors are perfect diamagnetic materials. The phenomenon of perfect diamagnetism in superconductors is calledthe Meissner effect. In superconductors the field lines are completely expelled. Also a superconductor repels a magnet and (by Newton’s third law) is repelled by the magnet.

Superconducting magnets can be used in variety of situations, for example, for running magnetically levitated super fast trains.

Magnetic lines prefer to pass through air than through a diamagnetic material & through a ferromagnetic material than through air.