Materials suitable for permanent magnets should have

When a magnetic substance is heated,then it

There are $2.0 \times 10^{24}$ molecular dipoles in a paramagnetic salt. Each has a dipole moment of $1.5 \times 10^{-23} \text{ A m}^2$. Find the maximum (saturation) magnetization in the specimen. (in $\text{ A m}^2$)

$A$ uniform magnetic field parallel to the plane of paper existed in space,initially directed from left to right. When a bar of soft iron is placed in the field parallel to it,the lines of force passing through it will be represented by which figure?

For two types of magnetic materials $A$ and $B$,the variation of $\frac{1}{\chi}$ ($\chi$: magnetic susceptibility) versus temperature $T$ is shown in the figure. Then:

Which of the following is the most suitable material for making a permanent magnet?