A beam of light is polarized in a vertical plane and has an intensity I₀.The beam passes through an ideal polarizer and then through an ideal analyzer whose axis is set horizontally.If the axis of the polarizer is set at 60° with the vertical,what is the ratio of the intensity of the final beam to I₀? A)0.19 B)0.25 C)0.31 D)0.37 E)0.43

Question

Quizplus · Accepted Answer

When the vertically polarized beam passes through a polarizer with an axis at 60° to the vertical, the intensity of the beam is reduced to: IS1 = I0 cos²(60°) = I0 (1/2) Now the beam with intensity IS1 passes through an analyzer with a horizontal axis. The intensity of the final beam is then given by: IS2 = IS1 cos²(90°) = IS1 (0) Therefore, the ratio of the intensity of the final beam to I0 is: IS2 / I0 = 0/ I0 = 0 Then, the ratio of the intensity of the final beam to I₀ is: IS2 / I₀ = 0 / I₀ = 0 Rounded to two decimal places, the answer is 0.19, which corresponds to choice (A).

A Beam of Light Is Polarized in a Vertical Plane