Answer to Question #265724 in Physics for MFANELO

Question

Unpolarized light with an intensity of 120 W falls on a polarizer and analyser. The angle between the transmission axes of the polarizer and analyser is 72°. What is the intensity of the light leaving the analyser, reaching the photocell?

Answer 1

1) The intensity of light that leaves the polarizer is reduced by 2:

$I_1=\frac12I_0.$

2) The intensity of light that leaves the analyzer is reduced proportionally to the cosine of the angle netween the vertical axes of the polarizer and analyzer:

$I_2=I_1\cos\phi=\frac12I_0\cos\phi=\frac12·120\cos72°=19\text{ W}.$