A cyclist mounts a small plane mirror exactly perpendicular to the road at the rear…
PHYSICS · Single correct · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A cyclist mounts a small plane mirror exactly perpendicular to the road at the rear of his bicycle. When the headlights of a car behind him shine on the mirror, most of the light returns toward the car. Which feature of mirror reflection chiefly causes this effect?
(a) The mirror reverses left and right (lateral inversion), so light retraces its path.
(b) At normal incidence the law of reflection breaks down, forcing the light to return toward the source.
(c) The incident light strikes the mirror at an angle of incidence of 0∘, so by the law of reflection it is sent back along the same path.
(d) Because the mirror surface is highly polished, almost all light is reflected straight back regardless of angle.