Question

The relation connecting magnetic susceptibility ${\chi }_m$ and relative permeability ${\mu }_r$ is

• A. ${\chi }_m={\mu }_r+1$
• B. ${\chi }_m={\mu }_r-1$
• C. ${\chi }_m=\frac{1}{{\mu }_r}$
• D. ${\chi }_m=3(1+{\mu }_r)$

Answer 1

Answer: (B)

Total magnetic flux density $B$ in a material is the sum of magnetic flux density in vacuum $B_0$
produced by magnetising force and magnetic flux density due to magnetisation of material
$B_m$ ie, $B=B_0+B_m$
$\Rightarrow$ $B={\mu }_{0}H+{\mu }_{0}I={\mu }_0(H+I)$
$={\mu }_{0}H(1+{\chi }_m)$
Also ${\mu }_r=(1+{\chi }_m)$