Trying to find the right answer to this..

Wave Optics

Question

If the angle between the axis of polariser and the analyser is 45°, write the ratio of the intensities of original light and transmitted light after passing through the analyser.

Answer

Given ,
Angle between the pass axis of polariser and analyser = 45^o

Let, I_o be the intensity of original light. Then,

Intensity of original light passing through the polariser = Io2

Intensity of light passing through the analyser is,
I = Io2cos245o

⇒ IoI = 2cos2 45 = 2(12)2=41
Thus, ratio of intensities of original light to transmitted light is 4:1.