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 $k_{r}=k_{0}$
$\therefore \mu=\sqrt{\mu_{0} k_{0}}$