$A$ ferromagnetic material is heated above its $Curie$ temperature. Which one is a correct statement?

Given below are two statements; one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ Electromagnets are made of soft iron.
Reason $R:$ Soft iron has high permeability and low retentivity.
In the light of the above statements,choose the most appropriate answer from the options given below.

$A$ sphere of gold when brought towards a powerful magnet experiences:

Which of the following statements are true about the magnetic susceptibility ${\chi _m}$ of a paramagnetic substance?

The most exotic diamagnetic materials are

An example of a perfect diamagnet is a superconductor. This implies that when a superconductor is placed in an external magnetic field of intensity $B$,the magnetic field $B_s$ inside the superconductor will be such that