$A$ paramagnetic salt contains $2 \times 10^{26} \, m^{-3}$ atomic dipoles. Each dipole has a magnetic moment of $1.5 \times 10^{-23} \, A \cdot m^2$. What is the saturation magnetization?

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.

$A$ paramagnetic sample shows a net magnetization of $0.8 \text{ A m}^{-1}$ when placed in an external magnetic field of strength $0.8 \text{ T}$ at a temperature of $5 \text{ K}$. If the temperature is raised to $20 \text{ K}$, then the magnetization becomes: (in $\text{ A m}^{-1}$)

What is a diamagnetic substance?

At a temperature of $30\,^{\circ}\text{C}$,the susceptibility of a ferromagnetic material is found to be $\chi$. Its susceptibility at $333\,^{\circ}\text{C}$ is......$\chi$.

$A$ small bar of diamagnetic substance is placed in a non-uniform magnetic field. In which direction does it move? Explain.