At a temperature of $30\,^oC$,the susceptibility of a ferromagnetic material is found to be $\chi$. Its susceptibility at $333\,^oC$ is....$\chi$.

The magnetic susceptibility of the material of a rod is $499$. Permeability of vacuum is $4 \pi \times 10^{-7} \ H/m$. The absolute permeability of the material of the rod in $H/m$ is:

Susceptibility of $Mg$ at $300\, K$ is $1.2 \times 10^{-5}$. The temperature at which susceptibility will be $1.8 \times 10^{-5}$ is......$K$.

What are the dimensions of $\chi$,the magnetic susceptibility? Consider an $H$-atom. Guess an expression for $\chi$,up to a constant,by constructing a quantity of dimensions of $\chi$ out of parameters of the atom: $e, m, v, R$ and $\mu_0$. Here,$m$ is the electronic mass,$v$ is electronic velocity,$R$ is Bohr radius. Estimate the number so obtained and compare with the value of $|\chi| \approx 10^{-5}$ for many solid materials.

An iron rod of cross-sectional area $2 \times 10^{-5} \ m^2$ is subjected to a magnetizing field intensity of $2000 \ A/m$. If the magnetic flux produced in the rod is $6.28 \times 10^{-4} \ Wb$,what is the magnetic permeability of the rod?

Curie's law states that