Electromagnets are made of soft iron because soft iron has

$A$ substance is placed in a non-uniform magnetic field. It experiences a weak force towards the strong field. The substance is . . . . . . type.

$A$ paramagnetic material has $10^{28} \text{ atoms/m}^3$. Its magnetic susceptibility at temperature $350 \text{ K}$ is $2.8 \times 10^{-4}$. Its susceptibility at $300 \text{ K}$ is

The materials suitable for making electromagnets should have

The relative permeability $(\mu_r)$ of a ferromagnetic substance varies with temperature $(T)$ according to the curve shown in the figure.

$A$ paramagnetic sample shows a net magnetisation of $8 \text{ Am}^{-1}$ when placed in an external magnetic field of $0.6 \text{ T}$ at a temperature of $4 \text{ K}$. When the same sample is placed in an external magnetic field of $0.2 \text{ T}$ at a temperature of $16 \text{ K}$,the magnetisation will be