Question

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

• A. Similar in nature and both are due to interference of light
• B. Different in nature and rainbow is due to interference of light, while colour of this film is due to diffraction
• C. Similar in nature and both are due to refraction of light
• D. Different in nature and rainbow is due to refraction, while colour of thin film is dues to interference of light

Answer 1

The correct option is D Different in nature and rainbow is due to refraction, while colour of thin film is dues to interference of light

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.