A ray of light is incident obliquely at a boundary separating two media . What is its behaviour if (1) the refractive index of the second medium is grater than that of the first medium (2) the refractive index of the first medium is greater that that of the second medium ? Draw the corresponding neat and labelled diagrams.

Explanation

Consider a ray of light incident obliquely at a boundary separating two media .
(1) If the refractive index of the second medium is greater than that of the first mediu, the ray bends towards the normal at the point of incidence at it travels from the first medium ( optically rarer medium)to the second medium ( optically denser medium ) . The angle of refraction ( r ) is less that n the angle of incidence ( i ) .


(2) If the refractive index of the first, medium is greater than that of the second medium , the ray bends away from the normal at the point of incidence as it travels from the first medium ( optically denser medium) , to the second medium ( optically rarer medium ) . The angle of refraction ( r ) is greater than the angle of incidence ( i).