Question

Unpolarised light of intensity i is incident on system of 2 polarisers.A followed by

b.The intensity of emergent light is i/2 . Third polariser c

Answer 1

As we have learned

malus law-

I=I'cos²Ф

Ф=angle made by E vector with transmission axis

I=intensity of transmitted light after polarisation

I'=intensity of incident light

both A and B should have same orientation of transmission axis only then we will have intentisity of I/2

let c makes angle α with A then cos α = (2/3)^1/4