A ray of light goes from medium 1 to medium 2. Velocity of light in the two media are c1 and c2 respectively. For an angle of incidence 0 in medium 1, the corresponding angle of refraction in medium 2 is ө/2.
(i) Which of the two media is optically denser and why?
(ii) Establish the relationship between ө, c1 and c2.
Given,
i) Angle of incidence in medium 1 =
Angle of refraction in medium 2 =
Angle of refraction in medium 2 is less than angle of incidence in medium 1. That is, the ray is bending towards the normal. Therefore, medium 2 is optically denser than medium 1.
ii) Using Snell's law,
=
= 2 cos
Also, refractive index
This implies,
i.e.,
which is the required relationship between ө, c1 and c2 .