A point source S of light is placed at a depth d below the surface of water in a large and deep lake. Fraction of light that escapes in space above directly from water (refractive index $$= \mu$$) surface is given by

A

$$\sqrt{1 - \frac{1}{\mu^2}}$$

B

$$\frac{1}{2}\sqrt{1 - \frac{1}{\mu^2}}$$

C

$$\frac{1}{2}\left\{1 - \sqrt{1 - \frac{1}{\mu^2}}\right\}$$

D

depends on d and increases with increasing d