A green light is incident from the water to the air - water interface at the critical angle `(theta)`. Select the correct statement.

Options

A. The spectrum of visible light frequency is more than that of green light will come out of the air medium.
B. The entire spectrum of visible light will come out of water at various angles to the normal.
C. The entire spectrum od visible light will come out of water at an angle of `90^(@)` to the normal.
D. The spectrum of visible light whose frequency is less than that of green light will come out of the air medium.

Answer

D

Explanation

As shwon in Fig. green light incident at critical angle `theta` gets totally internally reflected.

For frequencies less than green light. Wave-length is higher, refractive index is lower , critical angle is higher. Therefore, these frequencies will emerge out into the air, without suffering total internal reflection. Choice (d) is correct.