Question

Which of the following is correct for the reflected ray if a light ray strikes a plane mirror at an angle of 50° from the normal?

a. 40° from the surface of the mirror

b. 40° from the normal

c. 50° from the surface of the mirror

d. 90° from the normal

I have been stuck on this question for a while and I think it is because I am not sure I truly understand the question so I am not entirely convinced that I know the correct answer. I think the answer is either 40 degrees from the normal or 90 degrees from the normal but I do not know for sure. If you could help me answer this question and explain it to me it would be greatly appreciated.

Answer 1

The angle of reflection is the same as the angle of incidence.

Since incidence is 50° from the normal, so is the reflection.

Since the normal is 90° from the surface,

50° from normal = 40° from surface

So, the answer is (a)