Question

Which of the following is a necessary condition for total internal reflection?

(a) The angle of incidence in the denser medium must be greater than the critical angle for the two media

(b) The angle of incidence in the rarer medium must be greater than the critical angle for the two media

(c) The angle of incidence in the denser medium must be lesser than the critical angle for the two media

(d) The angle of reflection in the denser medium must be greater than the critical angle for the two media

This question was posed to me in unit test.

Query is from Ray Optics topic in section Ray Optics and Optical Instruments of Physics – Class 12

Answer 1

Correct answer is (a) The angle of incidence in the denser medium must be greater than the critical angle for the two media

The best I can explain: The necessary conditions for total internal reflection are ➔ the light must travel from an optically denser to an optically rarer medium and the angle of incidence in the denser medium must be greater than the critical angle for the two media.