Question

Expression for path difference between the reflected rays in case of thin films

Answer 1

These colours are due to interference between light waves reflected from the top and .... The path difference between the transmitted rays DG and HJ is, in a similar way, δ = 2µt cos r.

Answer 2

The film of transparent material like a drop of oil spread on the surface of water, show brilliant colours when exposed to an extended source of light. This phenomenon can be explained on interference basis. Here interference takes place between rays reflected from the upper and from the lower surface of the film.

 

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