Dispersion

Sunday, 7 October 2018

9:11 PM

For a given material, the index of refraction varies with the wavelength of the light passing

 

The index of refraction generally decreases with increasing wavelength

 

This explains how a rainbow is formed…
When a ray of light strikes a drop of water, the different wavelengths of the light deviate in with different angles, spreading out into a spectrum (violet deviates the most, red the least