Question

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

Options

• The entire spectrum of visible light will come out of the water at an angle of 90° to the normal.

• The spectrum of visible light whose frequency is less than that of green light will come out to the air medium.

• The spectrum of visible light whose frequency is more than that of green light will come out to the air medium.

• The entire spectrum of visible light will come out of the water at various angles to the normal.

Answer 1

The spectrum of visible light whose frequency is less than that of green light will come out to the air medium.

Explanation:

`"sin i"_"C" = 1/"n" and "n" prop 1/lambda`

For greater wavelength (i.e., lesser frequency) n is less. Hence, i_C would be more. Thus, these wavelengths will not suffer internal reflection and come out at angles less than 90°.