(i) What is the relation between critical angle and refractive index of a material ?
(ii) Does critical angle depend on the color of light ? Explain.

Explanation

(i) `mu= sin i_(c) or n_(21)= sin i_(c)`
Where `n_(21)` is the refractive index of rare medium 1 with respect to denser medium 2.
(ii) As `mu` depends on wavelength, therefore critical angle for the same pair of media in contact wil be different for different colours.