(a) State Snell’s law of refraction.
(b) When a ray of light travelling in air enters obliquely into a glass slab, it is observed that the light ray emerges parallel to the incident ray but it is shifted sideways slightly. Draw a ray diagram to illustrate it.
(a) The ratio of sine of angle of incidence to the sine of angle of refraction is constant for the light of given colour and given pair of medium.
(b)The diagram is as shown :
