Solution

These are the laws of refraction of light given below: (a) The incident ray, the refracted ray and the normal to the surface of separation of two media at the point of incidence all lie in the same plane. (b) The ratio of sine of angle of incidence to the sine of angle of refraction is constant. Thus, angle of incidence ‘i’ and the angle of refraction ‘r’ are related as sin i / sin r = n₂₁ (a constant) n₂₁ is the refractive index of the second medium with respect to the first medium.