A ray of light is incident at 60∘, on a glass-air interface. Then the light ray will be
Use : [μglass = √2 , μair = 1]
reflects back into glass
ic = sin−1 1μglass
ic = sin−1 1√2 μw = √2
We get ic=45∘
As angle of incidence > ic
Hence Total Internal Reflection occurs.