Question

Due to which phenomenon, does oil floating on water look coloured. What should be the thickness of the film for such effect to be visible?

Answer 1

A combination of refraction and reflection within the oil film gives rise to all the colors of the rainbow. Separation of the colors occurs as the sunlight passes through the air/oil surface, and is reflected at the oil/water surface.

here is your answer

MARK IT BRAINLIST PLEASE