Question

Question # 4: Keeping the laser-light source at the same angle, move it up and down vertically so it strikes different points on the raindrop. From your observation of the refracted light emerging from the raindrop at the bottom, why can no one observe a rainbow when the sun is high in the sky (your answer should discuss the refracted light relative to an observer on the ground

Answer 1

When we move light source up and down and go nearly on the top or bottom .. light rays will pass without bending . So there will be no deviation in the path .

As there is no deviation in the path so light spectrum will not be observed .

Same is the case of rainbow , when light passes at some angle then there will be path deviation in different colours ( as they have different wavelengths)

But when sun is at the top then deviation will not be there so we will see only white light . As a result rainbow will not form