what is law of refraction?

Laws of refraction

There are two laws of refraction.

First law of refraction

The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant. This is known as Snell’s law . Mathematically, it can be given as follows:

Here, is the relative refractive index of medium b with respect to medium a.

Second law of refraction

The incident ray, the refracted ray, and the normal to the interface of two media at the point of incidence – all lie in the same plane.