question_answer

Consider a ray of light travelling from a denser to a rarer medium. If it is incident at the critical angle then

A)  it will emerge out into the rarer medium

B)  it will undergo total internal reflection

C)  it will travel along the interface separating the two media

D)  it will retrace its path

Correct Answer: C

Solution :

 If a ray of light travelling from a denser to a rarer medium with angle of incidence same as critical angle, the ray will travel along the interface separating the two media.