# If μo be the permeability and ko , the dielectric constant of a medium , its refractive index is given by

Q: If μo be the permeability and ko , 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) $\sqrt{\mu_0 k_0}$

Sol: $\large \mu = \frac{c}{v}$ ;

Where ,  $\large c = \frac{1}{\sqrt{\mu_0 k_0}}$  and $\large v = \frac{1}{\sqrt{\mu_0 k_0 \mu_r k_r}}$

$\large \mu = \frac{\frac{1}{\sqrt{\mu_0 k_0}}}{\frac{1}{\sqrt{\mu_0 k_0 \mu_r k_r}}}$

$\large \mu = \sqrt{\mu_r k_r}$

Given , $\large \mu_r = \mu_0 \; and , k_r = k_0$

Then , $\large \mu = \sqrt{\mu_0 k_0}$