Define the following terms:

(a) Incident ray

(b) Refracted ray

(c) Angle of incidence

(d) Angle of refraction

(a) Incident ray — The ray of light falling on the surface separating the two media is called the incident ray.

(b) Refracted ray — The ray of light traveling in the other medium in the changed direction is called the refracted ray.

(c) Angle of incidence — The angle between the incident ray and the normal is called the angle of incidence (i).

(d) Angle of refraction — The angle between the refracted ray and the normal is called the angle of refraction (r).