Question

A ray of light makes an angle of 10^o with the horizontal above it and strikes a plane mirror which is inclined at an angle θ to the horizontal. The angle θ for which the reflected ray becomes vertical is

• A. 40⁰
• B. 50⁰
• C. 80⁰
• D. 100⁰

Answer 1

Answer: (A)

40⁰

Answer 2

From figure

$\theta + \theta + 10 = 90$

$\Rightarrow \theta = 40 ^ { \circ }$