A ray of unpolarized light is incident on a glass block at an angle of incidence in such a way that the reflected ray is completely plane polarized. The ray that represents the refracted ray is
A) 1
B) 2
C) 3
D) 4
E) 5

Question

A ray of unpolarized light is incident on a glass block at an angle of incidence in such a way that the reflected ray is completely plane polarized. The ray that represents the refracted ray is
A) 1 
B) 2 
C) 3 
D) 4 
E) 5

Quizplus · Accepted Answer

When unpolarized light is incident on a surface at a certain angle of incidence, the reflected light becomes completely polarized in the plane of incidence, and the refracted light is partially polarized perpendicular to the plane of incidence. In the given diagram, the incident ray is unpolarized and is incident at an angle such that the reflected ray is completely plane polarized. This means that the plane of incidence is horizontal. The only refracted ray that is partially polarized perpendicular to the plane of incidence is Ray 3, making it the correct choice. Rays 1, 2, 4, and 5 are all polarized in the plane of incidence or not polarized at all.

A Ray of Unpolarized Light Is Incident on a Glass