Question

The angle between the incident ray and the refracted ray of a prism is called angle of ______
(A) Reflection
(B) Deviation
(C) Prism
(D) Difference

Answer 1

Hint : To answer this question, we have to consider the basic definition of each of the types of angles that are given in the question. Then relating them with the angle asked in the question, we can get the correct answer after the elimination of all of the incorrect answers.

Complete step by step answer
A prism is a transparent medium in which refraction of light takes place which is incident on its surface. When a light ray is incident on its surface, it gets bent due to the higher refractive index of the prism material than that of the air. So the light ray is deviated from its original path. The prism used for analysing the path of the rays is usually taken to be of the triangular shape.
We know that the angle of reflection is the angle between the incident ray and the normal to the reflecting surface at the point of incidence. But we see that for a prism, no appreciable amount of reflection takes place.
So the option A is incorrect.
The angle of prism is the angle between the two lateral faces of a prism. It is fixed for a given prism and does not depend on the path of the incident or the refracted rays.
So the option C is also incorrect.
Now, the angle of deviation is the measure of the deflection of the incident ray of light from its original path after it has been refracted from the surface of a prism. So the angle of deviation is equal to the angle between the incident ray and the refracted ray of a prism.
Hence, the correct answer is option B.

Note
Usually, the angle of deviation is measured as the total deviation of the incident light ray at the two faces of the prism. So it is measured as the angle between the incident ray and the emergent ray. But we were asked about the angle between the incident ray and the refracted ray. So the best choice is angle of deviation.