Two polarizing disks whose planes are parallel and centred o

Two polarizing disks whose planes are parallel and centred on common axis. The directions of their transmission axes relative to the vertical are respectively: 1 = 16.0°, and 2 = 42.0o. An unpolarized beam of light is incident onto the first polarizer with an intensity of I0 = 11.5 W/m². Calculate the transmitted intensity through both polarizers.

This is not how you do it: From law of Malus\'I1 = (Io)*cos^2(theta)from the first polarizerI1 = (11.5)cos^2(16) = 10.62 W/m^2from the second polarizerI2 = (I1)*cos^2(theta)=10.62 W/m^2 cos^2 ( 42-16)=8.57 W/m^2

Solution

The Intensity of unpolarized light through a polarizer becomes half i.e

I₁=I_o/2 =11.5/2

I₁=5.75 W/m²

From mauls law Intensity of Second polarizer is

I₂=I₁Cos(42-16)

I₂=5.75Cos(26)

I₂=5.17 W/m²