Question

A vertical ray of light strikes the horizontal surface of some water:

1. What is the angle of incidence?
2. What is the angle of refraction?

Answer 1

1. Angle of incidence is 0° because the light ray is travelling along the normal, and the angle of incidence is the angle between the light ray and the normal.
2. If the incident ray falls normally on the surface, no bending of the light ray takes place. So, the angle of refraction is also 0°.