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

Answer:

a.0.5 Io

Explanation:

The fraction of light passing through the first polarizer will be

$I_1=\frac{I_0}{2}=0.5I_0$

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