Q.17. Explain how Meissener effect proves the
superconductor is a perfect dimagnetic material.
(AKTU. 2014 - 15)
Ans. A
superconductor is a perfect dimagnetic. The reason is that the magnetic induction
B in a superconductor is zero.
Therefore, for
superconductors,
B = m0(H + M) = 0 or M = - H ........(i)
where, H = magnetising
field intensity and M = intensity of magnetization
The magnetic
susceptibility is given by
........(ii)
From eq.(i) and (ii), we
get
........(iii)
This is the maximum value for
susceptibility of a diamagnetic material. In this sense, a superconductor is a
perfect diamagnet.
