Question

Which if the following is/are necessary conditions for total internal reflection

• A. The light must travel from a denser medium to a rarer medium
• B. The angle of incidence must be greater than the critical angle for the pair of media
• C. Both
• D. None

Answer 1

The correct option is C Both

correct answer (c)

There are two necessary conditions for total internal reflection
a) The light must travel from a denser medium to a rarer medium
b) The angle of incidence must be greater than the critical angle for the pair of media

Total internal reflection is a phenomenon which occurs when a propagating wave strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface. If the refractive index is lower on the other side of the boundary. Under ordinary conditions, the evanescent wave transmits zero net energy