Question

A light ray makes an angle of incidence ${60}^o$, when it falls on a plane reflecting sheet. The glancing angle of reflection will be :

• A. ${60}^o$
• B. ${30}^o$
• C. ${45}^o$
• D. ${90}^o$

Answer 1

The correct option is B ${30}^o$

Glancing angle is the angle between the ray and the surface instead of angle between the ray and normal to the surface.

Glancing angle of incidence

$={90}^o-$Angle of incidence (which is same as the angle of reflection)

$={90}^o-{60}^o={30}^o$