Question

Two linear polarizing filters are placed one behind the other, so that their transmission directions are parallel to one another. A beam of unpolarized light of intensity Io is directed at the two filters. What fraction of the light will pass through both filters?a.0.5 Iob.0c.2 Iod.0.25 Ioe. Io

Answer 1

a.0.5 Io

Step-by-step explanation:

The fraction of light passing through the first polarizer will be

`I_1=(I_0)/(2)=0.5I_0`

The fraction of light passing through the second polarizer will be

`I_2=0.5I_0cos^2\theta`

where

`\theta` = Angle between the filters

here, as the transmission directions are parallel to one another

`\theta=0`

`I_2=0.5I_0cos^20\\\Rightarrow I_2=0.5I_0\\\Rightarrow I_2=I_1`

Hence,
`0.5I_0` will pass through both filters