Question

An unpolarized light beam with intensity I0 is first passed through an ideal polarizer. At this instant, the light is polarized. We then pass that light through 3 more identical polarizers having parallel axes of transmission to each other. If the transmission axis of the final polarizer makes an angle of 45 ∘∘ with the electric field direction of the polarized light, what is the intensity of the emerging light?

Answer 1

Answer:

The intensity of the emerging light reduced to 25%

Explanation:

Given :

Unpolarized light intensity = $I_{o}$

Initial polarizer angle = 0°

Final polarizer angle between optic axis and transmission axis = 45°

Unpolarized light passes through first polarizer the intensity reduces to half.

after second polarizer the intensity is half till the last polarizer,

   $I_{3} = \frac{I_{o} }{2} \cos^{2} 45$

   $I_{3} = \frac{I_{o} }{4}$

Therefore, the intensity of the emerging light reduced to 25%