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

Data : n = \(\frac43\), 

i = 90\(^\circ\) - 40\(^\circ\) = 50\(^\circ\)

n = \(\cfrac{sin\,i}{sin\,r}\)

\(\therefore\) sin r = \(\cfrac{sin\,i}{n}\) = \(\cfrac{sin\,50^\circ}{4/3}\)

= \(\cfrac{0.7660}{4/3}\)

∴ The angle of refraction, r = sin^-1 (0.5745) = 35°4′