The magnetic susceptibility $\chi$ for superconductors is . . . . . . .

Explain quantitatively the order of magnitude difference between the diamagnetic susceptibility of ${N_2} \left( { \sim 5 \times {{10}^{ - 9}}} \right)$ (at $STP$) and ${Cu} \left( { \sim {{10}^{ - 5}}} \right)$.

If $M_z$ is the magnetization of a paramagnetic sample,$B$ is the external magnetic field,$T$ is the absolute temperature,and $C$ is the Curie constant,then according to Curie's law in magnetism,the correct relation is:

$A$ diamagnetic material in a magnetic field moves:

$A$ paramagnetic sample shows a net magnetisation of $6 \, A/m$ when it is placed in an external magnetic field of $0.4 \, T$ at a temperature of $4 \, K$. When the sample is placed in an external magnetic field of $0.3 \, T$ at a temperature of $24 \, K$,then the magnetisation will be $...... \, A/m$.

Provide information about electromagnets.