Question

An incident ray strikes a plane mirror at an angle at 15° with the mirror. the angle between the reflected ray and the incident ray is
(a) 15°
(b) 30°
(c) 150°
(d) 140°

Answer 1

(c) 150°

Given:
Angle of incident ray with the mirror = 15°
Therefore,
Angle of incidence = Angle of incident ray with the normal
= 90° $-$ 15°
= 75°
We know that angle of reflection is always equal to angle of incidence. Therefore, we have:
Angle of reflection = Angle of reflected ray with the normal = 75°
Hence, angle between the reflected and incident rays = 75° + 75° = 150°