QuestionDetails: three polarizers are placed along a common axis with thetranmission axis of the first polarizer placed vertically, thetransmission axis of the second placed 30o from thevertical and the transmission axis of the 90o from thevertical. if un polarized (incoherent) light of intensityIo is incident on the first polarizer what fraction ofthe intensity is thransmitted through the third polarizer? QuestionDetails:QuestionDetails: three polarizers are placed along a common axis with thetranmission axis of the first polarizer placed vertically, thetransmission axis of the second placed 30o from thevertical and the transmission axis of the 90o from thevertical. if un polarized (incoherent) light of intensityIo is incident on the first polarizer what fraction ofthe intensity is thransmitted through the third polarizer?
Explanation / Answer
Let the intensity unpolarised light be I Intensity of the polarised light after 1 st polariser I' = I / 2 Intensity of the polarised light after 2 nd polariser I " = I' cos ^ 2 ( 30 ) = 0.375 I Intensity after 3 rd polariser I "' = I " cos ^ 2 ( 90 -30 ) = 0.09375 I So, required fraction = 0.09375 I / I = 0.09375