A laser beam is incident on a stationary plane mirror at an angle of incidence of
PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A laser beam is incident on a stationary plane mirror at an angle of incidence of 40∘. The mirror is then rotated, about an axis lying in its plane and perpendicular to the plane of incidence, through an angle of 5∘ while the incident beam remains fixed.
(i) Calculate the new angle of reflection after the mirror rotation.
(ii) Determine through what total angle the reflected beam has turned from its original direction.
(iii) If a laboratory experiment requires the reflected beam to sweep through 60∘, what minimum angle of rotation of the mirror would achieve this, keeping the incident beam fixed?