Question

A ray of light is incident on an equilateral glass prism placed on a horizontal table. For minimum deviation which of the following is true?

• A. $PQ$ is horizontal
• B. $QR$ is horizontal
• C. $RS$ is horizontal
• D. Either $PQ$ or $RS$ is horizontal

Answer 1

The correct option is B $QR$ is horizontal

In the minimum deviation position, the refracted ray is parallel to the base of the prism.

so option (B) is the right choice.