Polarizing angle: The angle of incidence at the interference of two media (rarer and denser) at which the reflected ray is completely plane polarized is called polarizing angle. The polarizing angle for a medium of refractive index μ is given by
\(\mu=\tan\left(\theta_p\right)\) ; θp = polarizing angle.
Since, the refractive index of a medium depends upon the wavelength of the light by the Cauchy's relation \(\mu=A+\frac B{\lambda^2}\), where, A and B are constant and λ be the wavelength of the light. Thus, the polarizing angle also depends upon the wavelength of light.