Question

What is refraction of light? How is it related to refractive index?

Answer 1

The phenomenon of change in the direction of propagation of light when it passes obliquely from one transparent medium to another is called refraction of light.

For a given angle of incidence ($i\ne 0$) the extent of refraction (bending) of light is different in different media. If the refractive index of the second medium with respect to the first medium is greater than 1, the greater the refractive index, the greater is the bending of the ray of light towards the normal. If the refractive index of the first medium is less than 1, then greater the refractive index, the lesser is the bending of the ray of light away from the normal.

Relation to the refractive index are :

$\frac{sini}{sinr}=n$

where; $sini$ =sine of angle of incidence.

$sinr$=sine of angle of refraction