By putting a magnetic substance of volume $30\, cm^3$ in a magnetising field of strength $\frac{1250}{\pi} \, A/m$,the value of the produced magnetic moment is $6\, A\cdot m^2$. Calculate the value of magnetic induction produced in the substance in $T$.

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.

$A$ solenoid has a core of a material with relative permeability $400$. The windings of the solenoid are insulated from the core and carry a current of $2 \; A$. If the number of turns is $1000$ per metre,calculate $(a) \; H$,$(b) \; M$,$(c) \; B$ and $(d)$ the magnetising current $I_m$.

$A$ solenoid having $400$ turns per metre has a core of a material with relative permeability $400$. When a current of $0.5 \ A$ is passed through it,the magnetization of the core material in $Am^{-1}$ is nearly

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: (in $\text{ A/m}$)