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Question
What is the cause of dispersion of light
Solution
Cause of dispersion: Different colours of white light have different wavelengths. The wavelength of violet light is smaller than that of red light. The refractive index of a material in terms of the wavelength of the light is given by Cauchy’s expression.
`mu=a+b/lambda^2+c/lambda^4`
Here, a, b and c are constants for the material.
Thus, a material offers different refractive indices to lights of different wavelengths. This is the cause of dispersion of light
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