Question

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

• A. The entire spectrum of visible light will come out of the water at an angle of $90^\circ$ to the normal
• B. The spectrum of visible light whose frequency is less than that of green light will come out of the air medium
• C. The spectrum of visible light whose frequency is more than that of green light will come out to the air medium
• D. The entire spectrum of visible light will come out of the water at various angles to the normal

Answer 1

Answer: (B)

$\sin \,\theta_{c}=\frac{1}{\mu}$

For greater wavelength (i.e. lesser frequency) $\mu$ is less
So, $\theta_{c}$ would be more. So, they will not suffer reflection and come out at angles less then $90^{\circ}$.