Question

The magnetic susceptibility of a material of a rod is $499$. Permeability of vacuum is $4\pi \times {10}^{-7}H/m$. The absolute permeability of the material of the rod meter is

• A. $\pi \times {10}^4$
• B. $2\pi \times {10}^{-4}$
• C. $3\pi \times {10}^{-4}$
• D. $4\pi \times {10}^{-4}$

Answer 1

The correct option is B $2\pi \times {10}^{-4}$

As ${\mu }_r=\frac{\mu }{{\mu }_0}$

And ${\chi }_m={\mu }_r-1$

${\mu }_r$ is relative permeability

${\mu }_0$ is permeability of free space (vaccum)

$\mu$ is permeability of the medium

${\chi }_m$ is magnetic susceptibility

$\therefore {\mu }_r=1+{\chi }_m=500$

$\therefore \mu ={\mu }_r{\mu }_0=500\times 4\pi \times {10}^{-7}$

$=2\pi \times {10}^{-4}$