Question

The magnetic susceptibility of a material of a rod is $499$. Permeability of vacuum $\left({\mu }_0\right)$ is $4\pi \times {10}^{-7}H{m}^{-1}$. Absolute permeability of the material (in $H{m}^{-1}$) of the rod 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

Answer: (B)

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

Given : ${\mu }_o=4\pi \times {10}^{-7}H{m}^{-1}$

Magnetic susceptibility of a material of rod: ${\chi }_m=499$

$\therefore$ Absolute permeability of material of rod:

$\mu ={\mu }_o(1+{\chi }_m)$

or, $\mu =4\pi \times {10}^{-7}(1+499)=2\pi \times {10}^{-4}H{m}^{-1}$