Question

If ${\mu }_0$ and ${\epsilon }_0$ are respectively the permeability and permitivity of free space, $\mu$ and $\epsilon$ are the corresponding quantifies in a medium, then the refractive index of the medium with respect to free space is :

• A. $\sqrt{{\mu }_0{\epsilon }_0}$
• B. $\sqrt{\frac{\mu \epsilon }{{\mu }_0{\epsilon }_0}}$
• C. $\sqrt{\frac{{\mu }_0{\epsilon }_0}{\mu \epsilon }}$
• D. $\frac{1}{\sqrt{{\mu }_0{\epsilon }_0}}$

Answer 1

The correct option is B $\sqrt{\frac{\mu \epsilon }{{\mu }_0{\epsilon }_0}}$

Refractive index of the medium $n=\sqrt{{ϵ}_r{\mu }_r}$

Also, ${\mu }_r=\frac{\mu }{{\mu }_o}$ and ${ϵ}_r=\frac{ϵ}{{ϵ}_o}$

$⟹n=\sqrt{\frac{\mu ϵ}{{\mu }_o{ϵ}_o}}$