Question

A magnetising field of $2\times {10}^{3}A{m}^{-1}$ produces a magnetic flux density of $8\pi$. Tesla in an iron rod. The relative permeability of the rod will be

• A. ${10}^2$
• B. ${10}^0$
• C. ${10}^1$
• D. ${10}^4$

Answer 1

The correct option is D ${10}^4$

$\begin{array}{c}{\mu }_r=\frac{\mu }{{\mu }_0}=\frac{B}{H{\mu }_0}\\ B=8\pi T\\ H=2\times {10}^{3}A/m\\ {\mu }_r=\frac{8\pi }{2\times {10}^3\times 4\pi \times {10}^{-7}}={10}^4\end{array}$

Hence,

option $\left(D\right)$ is correct answer.