 # State laws of refraction

(a) State laws of refraction.
(b) A ray of light enters from a medium A into a slab made-up of a transparent substance B (as shown in the figure). Refractive indices of medium A and B are 2.42 and 1.65 respectively. Complete the path of ray of light till it emerges out of the slab. (a) The two laws are :
(i) The incident ray, the refracted ray and the normal to the interface of two transparent media at the point of incidence, all lie in the same plane.
(ii) The ratio of sine of angle of incidence to the sine of angle of refraction is a constant, for the light of a given colour and for the given pair of media. This law is also known as Snell’s law of refraction.
(b) The path of rays is as shown in figure : Laws of Refraction

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

2. The ratio of sine of angle of incidence to the sine of angle of refraction is a constant, for the light of a given color and for the given pair of media. This law is also known as Snell’s law of refraction.

N = sin i/ sin r

This constant is also called the refractive index of the second medium with respect to the first. 