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 Solved Paper-2015 ]
A)bends downwards
B)bends upwards
C)becomes narrower
D)goes horizontally without any deflection
Correct Answer:
B
Solution :
As we move up \[''\theta ''\]decreases bends upwards