A beam of initially polarized light of intensity Iunpol movi

A beam of initially polarized light of intensity I_unpol moving in the x direction is sent into a polarizing sheet that lies on the y - z plane with pass axis along the y axis. After that the light passes through another filter that also lies on the y - z plane but with pass axis at an angle 30degree from the y axis. The final intensity of the light is 1/2I_unpol 3/8I_unpol 1/8I_unpol 1/4I_unpol squareroot 3/4I_unpol.

Solution

In the first pass the light averages out so intensity = I/2

After second pass through the 30 degree polariser intensity =I/2*cos²x = I/2*(sqrt(3)/2)²=3I/8