A beam of unpolarized light is incident on a transparent glass surface from air. It is observed that the reflected beam is completely linearly polarized. If the angle of refraction in the glass is 30^ , what is the speed of light in the glass medium? (Given the speed of light in vacuum c = 3 10^8 m/s )

Step-by-step solution

When the reflected beam is completely linearly polarized, the light is incident at Brewster's angle ( i_p ). At Brewster's angle, the reflected and refracted rays are mutually perpendicular. Therefore, the angle of incidence i_p and the angle of refraction r are related by: i_p + r = 90^ Given r = 30^ , we have: i_p = 90^ - 30^ = 60^ According to Brewster's law, the refractive index of the medium ( ) is: = (i_p) = (60^ ) = 3 The speed of light in the glass medium ( v ) is given by: v = c = 3 10^8 3 = 3 10^8 m/s Ans