A beam of monochromatic light travelling in water is incident on a flat glass surface
PHYSICS · Subjective · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A beam of monochromatic light travelling in water is incident on a flat glass surface. The incident ray makes an angle of 48∘ with the normal at the water–glass interface.
(i) Define the absolute refractive index of a medium.
(ii) Obtain an expression for the refractive index of glass with respect to water in terms of the angles of incidence and refraction at a single, plane interface.
(iii) In the experiment, the refracted ray inside the glass is found to make an angle of 30∘ with the normal. Calculate the refractive index of glass relative to water.
(iv) When the same set-up is used with violet light, the refracted angle becomes 28∘. Determine the refractive index of glass for violet light and hence find the difference between the refractive indices for red and violet light.
(v) Comment on what the result obtained in part (iv) indicates about the dispersive behaviour of glass.