Q. 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
Explanation
(b) During minimum deviation the ray inside the prism is parallel to the base of the prism in case of an equilateral prism.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.