The critical angle of a transparent crystal is `30^(@)` . What is the polarising angle of the crystal?

Explanation

If `mu` be the refractive index and `theta_( c)` be the critical angle of the crystal, then
`mu = (1)/(sin theta_( c)) = (1)/(sing 30^(@)) = 2 `
From Brewster's law we have,
` tani_(p) = mu ` [here `i_(p)` = polarising angle]
or, tan`i_(p) = 2 " " or, i_(p) = tan^(-1)(2) = 63.43^(@)`