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 $T$.

Oersted is a unit of

When a piece of a ferromagnetic substance is placed in a uniform magnetic field,the flux density inside it is four times the flux density away from the piece. The magnetic permeability of the material is

The dipole moment of each molecule of a paramagnetic gas is $1.5 \times 10^{-23} \, A \cdot m^2$. The temperature of the gas is $27 \, ^\circ C$ and the number of molecules per unit volume is $2 \times 10^{26} \, m^{-3}$. The maximum possible intensity of magnetization in the gas will be:

Which of the following relations is incorrect?
$(a) \ B = \mu_0(H + I)$
$(b) \ B = \mu_0(H + \chi_m)$
$(c) \ \mu_r = 1 + \chi_m$
$(d) \ \chi_m = I / H$
(Here,$I =$ intensity of magnetization and $H =$ magnetising field)

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: