question_answer

A beam of light consisting of red, green and blue colours is incident on a right-angled prism on face AB. The refractive indices of the material for the above red, green and blue colours are 1.39, 1.44 and 1.47 respectively. A person looking on surface A C of the prism will see [JEE ONLINE 26-05-2012]

A) no light

B) green and blue colours

C) red and green colours

D) red colour only

Correct Answer: D

Solution :

[d] For light to come out through face 'AC', total internal reflection must not take place.

i.e.,

or