Question

The speed of light in a medium is 2 by 3rd of the speed of light in vacuum. Find the refractive index of the medium

Answer 1

Hello,

The refractive index of medium the medium will be 2/3.
How??

Lets see ......

Refractive index =
$\frac{speed \: of \: light \: in \: medium1}{speed \: of \: light \: in \: medium2}$
Now
Medium one has speed of 2/3 rd of x
Where x is the speed of light in vacuum

Now,
Medium two is vacuum so,
Speed of light will be x m/sec.

Now,
Refractive index =
$\frac{ \frac{2}{3}x }{x} = \frac{2}{3}$
This refractive index can be also called as the absolute refractive index of the medium.

As the refractive index is in ratio to vacuum.

Hope this will be helping you ✌️