Q.

The intensity of transmitted light when a polaroid sheet, placed between two crossed polaroids at 22.5° from the polarization axis of one of the polaroid, is (I0 is the intensity of polarised light after passing through the first polaroid)             [2025]
 

1 I08  
2 I016  
3 I02  
4 I04  

Ans.

(1)

According to the Malus law,

      I=I0cos2(θ1)

      I1=I0                                                      (given)

      I2=I1cos2(θ2)

      I2=I0cos2(22.5)

      I2=I0(0.85)

      I3=I2cos2(θ3)=I0×0.85×cos2(67.5°)

      I3=I0×0.125

or   I3=I08