Question

A ray of light is incident on a water surface of refractive index `4/3` making an angle of 40° with the surface. Find the angle of refraction.

Answer 1

`n=4/3`, i = 90° - 40° = 50° 

`n = sini/sinr`

`sinr=sini/n`

`=(sin50°)/(4/3)`

`=0.7660/(4/3)`

`=0.5745`

The angle of refraction,

r = sin^-1(0.5745) = 35°4'