When an unpolarized light falls at a particular angle on a glass plate (placed in air), it is observed that the reflected beam is linearly polarized. The angle of refracted beam with respect to the normal i $s _______.$
(tan⁻¹ (1.52) = 57.7°, refractive indices of air and glass are 1.00 and 1.52, respectively)

Question

When an unpolarized light falls at a particular angle on a glass plate (placed in air), it is observed that the reflected beam is linearly polarized. The angle of refracted beam with respect to the normal i $s _______.$

(tan⁻¹ (1.52) = 57.7°, refractive indices of air and glass are 1.00 and 1.52, respectively)

G1 Physics · Accepted Answer

A linearly polarized reflected beam at the interface indicates incidence at Brewster's angle. Brewster's law gives tan i(B) = n(glass)/n(air) = 1.52/1.00 = 1.52. Therefore, i(B) = tan⁻¹(1.52) = 57.7°. At Brewster incidence, the reflected and refracted rays are perpendicular. Hence, i(B)+r = 90°. Therefore, r = 90°-57.7° = 32.3°. Correct option: B.