JEE Main 2020 Physics question
There is a small source of light at some depth below the surface of water (refractive index = ) 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 ]
Answer: (D)