A narrow beam of monochromatic light is incident on a plane mirror in a laboratory set-up.
PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A narrow beam of monochromatic light is incident on a plane mirror in a laboratory set-up.
(i) Define the terms (a) incident ray, (b) reflected ray and (c) normal at the point of incidence.
(ii) State the two laws governing reflection of light at a plane surface.
(iii) Using a neat, labelled ray diagram and elementary geometry, prove that the angle between the incident ray and the reflected ray is twice the angle of incidence.