There is a small source of light at some depth below the surface of water (refractive index \(=\frac{4}{3}\)) in a tank of large cross sectional surface area. Neglecting any reflection from the bottom and absorption by water, percentage of light that emerges out of surface is (nearly):
[Use the fact that surface area of a spherical cap of height h and radius of curvature r is 2πrh]
1
50%
2
34%
3
21%
4
17%