Question

A ray of light strikes the glass slab at an angle of ${50}^o$. What is the angle of incidence?

• A. ${50}^o$
• B. ${25}^o$
• C. ${40}^o$
• D. ${100}^o$

Answer 1

Answer: (C)

${40}^o$

The angle of incidence is defined as the angle between the normal drawn at the point of incidence and the incident light ray. Here the light ray is falling at the point of incidence at an angle of $50°$. Thus:

Glancing angle is given as ${50}^0$

Hence angle of incidence $={90}^0-{50}^0={40}^0$