In some ferromagnetic materials,magnetization disappears on the removal of the external magnetic field. Such materials are called:

Give some examples:
$(i)$ Ferromagnetic substances.
$(ii)$ Paramagnetic substances.

Any magnetic material loses its magnetic property when it is

Assertion: $A$ disc-shaped magnet is levitated above a superconducting material that has been cooled by liquid nitrogen.
Reason: Superconductors repel a magnet.

In a permanent magnet at room temperature,

$A$ sample of paramagnetic salt contains $20 \times 10^{24}$ atomic dipoles each of dipole moment $1.5 \times 10^{-23} \ J \ T^{-1}$. The sample is placed under a homogeneous magnetic field of $0.84 \ T$,and cooled to a temperature of $4.2 \ K$. The degree of magnetic saturation achieved is equal to $15 \%$. What is the total dipole moment (approximate) of the sample for a magnetic field of $0.98 \ T$ and a temperature of $2.8 \ K$? (Assume Curie's law).