Physics - Magnetism Question with Solution | TestHub

The net magnetic field $B$ inside a magnetic material is the sum of the magnetic field in vacuum produced by the external free current and the magnetic field produced by the magnetisation of the material.

Let $B_0$ be the magnetic field due to the external current and $B_M$ be the magnetic field due to the magnetisation of the material.

We know that $B_0={\mu }_{0}H$ and $B_M={\mu }_{0}M$.

Therefore, the net magnetic field is given by:

$B=B_0+B_M$

$B={\mu }_{0}H+{\mu }_{0}M$

$B={\mu }_0(H+M)$

Answer: $\mathrm{B}={\mu }_0(\mathrm{H}+\mathrm{M})$