The domain in a ferromagnetic material is in the form of a cube of side $2 \mu m$. The number of atoms in that domain is $9 \times 10^{10}$ and each atom has a dipole moment of $9 \times 10^{-24} A m^2$. The magnetization of the domain is (approximately):

If the magnetizing field on a ferromagnetic material is increased,its permeability

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.

$A$ substance has a mass of $1 \, g$ and a density of $5 \, g/cm^3$. Its magnetic dipole moment is $6 \times 10^{-7} \, A \cdot m^2$. What is the magnetization in $A/m$?

An iron rod of volume $10^{-4} \, m^3$ and relative permeability $1000$ is placed inside a long solenoid wound with $5 \, \text{turns/cm}$. If a current of $0.5 \, A$ is passed through the solenoid, then the magnetic moment of the rod is .... $A m^2$.

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......$K$.