$A$ Rowland ring of mean radius $15\; cm$ has $3500$ turns of wire wound on a ferromagnetic core of relative permeability $800$. What is the magnetic field $B$ (in $T$) in the core for a magnetizing current of $1.2\; A$?

Curie's law states that

The magnetic moment produced in a substance of mass $5 \ g$ is $6 \times 10^{-7} \ A \cdot m^{2}$. If its density is $5 \ g/cm^{3}$,then the intensity of magnetization in $A/m$ will be:

Magnetization of the sample is defined as:

The magnetic moment produced in a sample of $2 \text{ g}$ is $8 \times 10^{-7} \text{ A} \cdot \text{m}^2$. If its density is $4 \text{ g/cm}^3$, then the magnetization of the sample is:

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.