Q. When a ray of light is incident normally on a surface, then
A) Total internal reflection takes place
B) It passes undeviated
C) It undergoes dispersion
D) It gets absorbed by the surface
Explanation
(b) From Hugen’s principle, if the incident wavefront be parallel to the interface of the two media $(i = 0),$ then the refracted wavefront will also be parallel to the interface $(r = 0).$
In other words, if light rays fall normally on the interface, then on passing to the second medium they will not deviate from their original path.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.