A beam of unpolarized light is incident on the surface of a transparent medium. It is observed that the reflected light is completely plane-polarized when the angle of incidence is 60^ . The angle of refraction in the medium is:

Step-by-step solution

When unpolarized light is incident at the polarizing angle (Brewster's angle), the reflected light is completely plane-polarized. According to Brewster's law, at the polarizing angle i_p , the reflected and refracted rays are mutually perpendicular. Therefore, i_p + r = 90^ , where r is the angle of refraction. Given i_p = 60^ , we have: 60^ + r = 90^ r = 30^ Answer: 30^