Question

If ${\mu }_0$ be the permeability and $k_0$ the dielectric constant of a medium, its refractive index is given by

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

Answer 1

Answer: (C)

$\mu =\frac{c}{v}$
Now $c=\frac{1}{\sqrt{{\mu }_0{k}_0}}$
and $v=\frac{1}{\sqrt{{\mu }_0{k}_0{\mu }_r{k}_r}}$
$\therefore \mu =\sqrt{{\mu }_r{k}_r}$
But ${\mu }_r={\mu }_0$ and $k_r=k_0$
$\therefore \mu =\sqrt{{\mu }_0{k}_0}$