Glass Prism as a refracting medium | angle of prism

Last updated on May 16th, 2022 at 08:13 pm

In this post, we will just talk about some special features of prism that make it a suitable medium to test the refraction of light.

Subtopics discussed: Glass Prism as a refracting medium – features, and angle of prism

Glass Prism – features of prism that contribute refraction through it

To discuss the features we will refer to the above diagram.

In the prism, ∆ABC and ∆DEF are 2 opposite and parallel surfaces which are triangular.

ABED and ACFD surfaces are polished and act as the refracting surfaces.

∆ABC triangle is called the Principal Section of the prism (used in ray diagram)

AD line is called the refracting edge.

BCFE is the rectangular base of the prism

BAC angle is called the angle of the prism which is denoted by letter A

What is the angle of prism?

Two refracting surfaces of prism are not parallel to each other. But they are inclined on each other making an angle A called the angle of prism.

How the inclined refracting surfaces influence the overall refraction of light through a prism?

The inclined refracting surfaces influence the refraction in such a way that after each refraction at the separating surfaces (air to glass prism and then glass prism to air) the ray bends towards the base of the prism.

How can you find out the total deviation caused by the refraction through a glass prism using a formula?

We need to use this formula to find out the total deviation:
total deviation = angle of incidence + angle of emergence – the angle of prism
d = i + e – A