A light ray strikes a plane mirror such that the reflected ray makes a RIGHT ANGLE with the incident ray. The angle of incidence is:
A30°
B45°
C90°
D60°
Answer & Solution
Correct answer: B. 45°
If ∠i + ∠r = 90° and ∠i = ∠r (law of reflection), then 2∠i = 90°, so ∠i = 45°. (And the ray strikes the mirror at 45° from the surface as well.)
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