When a piece of a magnetic substance is put in a uniform magnetic field, the flux density inside it is four…
When a piece of a magnetic substance is put 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
$1$
$2$
$3$
$4$
Solution
Let magnetic flux density outside $=B_0$
Magnetic flux density inside a magnetic material,
$B=4 B_0$
We know that, $B=\mu_r B_o$
where, $\mu_r=$ Magnetic permeability of material
$\Rightarrow \quad \mu_r=\frac{B}{B_0}=4$