Unpolarized light of intensity 32 `Wm^(-3)` passes through three polarizers such that the transmission axis of the last polarizer is crossed with the first. If the intensity of the emerging light is `3 Wm^(-2)`, what is the angle between the transmission axces of the first two polarizers ? At what angle will the transmitted intensity be maximum ?

Explanation

`I_(2)=I_(1) cos^(2)(90-theta)=I^(')/2 cos^(2) theta sin^(2)theta=I^(')/8(sin 2theta)^(2)`
`3=32/8(sin 2theta)^(2)`
`sin2theta=sqrt(3)/2=sin60^(@) or sin 120^(@)`
`theta=30^(@) or 60^(@)`
`I_(2)/I^(')/8(sin 2theta)^(2)`
`I_(2)` i.e. intensity of emergent light will be maximum if `sin 2 theta=1 implies sin 2 theta=sin 90^(@)`
`theta=45^(@)`