Question

The rainbow and the rainbow-like colours seen on a thin film of oil on a water surface are two phenomenon. They are:​

Answer 1

Answer:

The rainbow is formed due to refraction, reflection and dispersion of light in the water droplets results in spectrum of light appearing in the sky.

The rainbow colors that appears on the thin film of oil on a surface is because of thin film interference.

when light falls on the oil layer, some light gets reflected and some gets transmitted, so, the light get splits into different colors(wavelengths),the wavelengths which are reflected interferes with each other and constructive and destructive interference is produced by the interference of reflected light.

so, those colours (wavelength) corresponding to constructive interference will appear.

Answer 2

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dispersion and total internal reflection happen because of refraction. The rainbow-like colours appearing on the thin film of oil floating on water, is due to the phenomenon of thin film interference.