question_answer

An un polarized beam of light is incident on a glass surface at an angle of incidence equal to the polarizing angle of the glass. Read the following statements: (i) The  reflected  beam is  completely polarized. (ii) The refracted beam is partially polarized. (iii) The angle between the reflected and the refracted beams is\[90{}^\circ \]. Which of the above statements is/are true?

A)  (i) only

B)  (ii)only

C)  (i) and (iii)

D)  All statements are correct

Correct Answer: C

Solution :

                 According to the Brewster?s theory the quantity of polarized light in reflected light depends upon angle of incidence. If angle of incidence is equal to a particular angle called polarizing angle\[({{i}_{p}}),\]then reflected beam is completely polarized. Also when light is incident at polarizing angle then reflected and refracted rays are mutually perpendicular, i.e.                 \[{{i}_{p}}+r={{90}^{o}}.\] Here,     \[{{i}_{p}}=\]angle of reflection \[r=\]angle of refraction Note: The polarising angle for air-glass is\[{{57}^{o}}\].