Give an explanation of superconductor a diamagnetism.

Explanation

Superconductors are different types of diamagnetic substances. The metals of superconductor are cooled at very low temperature which exhibits both perfect conductivity and perfect diamagnetism.
A superconductor, when it is cooled below the critical temperature, expelled the magnetic field and doesn.t allow the magnetic field to penetrate inside it. This phenomenon is called Meissner effect.
For these conductors (metals) `chi = 1 and mu_r = 0. " "[because mu_r = 1 + chi]`
Magnet repel the superconductor and it is repel by magnet.
Superconductor magnets are useful in high speed superfast trains that run high by a magnet.