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 · 4 Apr · Shift 1
PhysicsSingle correct+4 / -1Question 25 of 90
JEE Main 2015 · 4 Apr · Shift 1, Physics question 25
Answer and worked solution
Official answer: D
The wave is slower where the index is higher. The upper part of the wavefront (higher μ) travels slower than the lower part, so the wavefront tilts and the beam bends upwards, towards the higher index.
Topics:Huygens' principle