Question

What should be the angle of incidence of a ray falling on a plane mirror if the incident and reflected rays are perpendicular to each other?

• A. 0
• B.
• C. 25 m
• D. 25 cm

Answer 1

The correct option is C

25 m

Since the incident and reflected rays are perpendicular to each other, the angle between them is ${90}^{\circ }$. We know that angle of incidence is always equal to the angle of reflection. So, $i+r={90}^o$

$\Rightarrow 2i={90}^o$

$\therefore i={45}^o$