question_answer

On a hot summer night, the refractive index of air is smallest near the ground and increases with height from the ground. When a light beam is directed horizontally, the Huygens’ principle leads us to conclude that as it travels, the light beam:          [JEE MAIN 2015]

A) bends downwards       

B) bends upwards

C) becomes narrower

D) goes horizontally without any deflection

Correct Answer: B

Solution :

[b]

As we move up decreases bends upwards