It is found that a laser bounced off a glass surface incident at 57 degrees produces a transmitted beam angle of 38 degrees with respect to the vertical.At what incident angle will the reflected laser beam be fully polarized?
A) 46$^{\circ}$
B) 36$^{\circ}$
C) 54$^{\circ}$
D) 43$^{\circ}$

Question

Quizplus · Accepted Answer

The angle of incidence and angle of reflection are equal, so the incident angle that produces a transmitted beam angle of 38 degrees is also 57 degrees. To find the angle at which the reflected beam is fully polarized, we need to use Brewster's law: the tangent of the angle of incidence equals the refractive index of the glass. For most glasses, the refractive index is around 1.5. Therefore, the angle of incidence that would result in full polarization of the reflected beam is arctan(1.5) or approximately 56.3 degrees. Choice C is closest to this value, so it is the best choice.

It Is Found That a Laser Bounced Off a Glass ∘^{\circ}∘

It Is Found That a Laser Bounced Off a Glass $^{\circ}$