Question

The speed of light in air is $3\times {10}^8$ m/s Calculate the speed of light in glass. The refractive index of glass is $1.5$.

Answer 1

Given,

Speed of light in air, $c=3\times {10}^{8}m/s$

Refractive index of glass, $\mu =1.5$

Speed of light in glass, $v$ =?

We know that,

$\frac{c}{v}=\mu$

$\therefore v=\frac{3\times {10}^{8}m/s}{1.5}$

$v=2\times {10}^{8}m/s$.