Intensity Through Multiple Polarizers — the NEET Physics formula with its derivation, variables, validity constraints and worked solver.
Intensity Through Multiple Polarizers This law applies when monochromatic light passes sequentially through two or more polarizers (polaroid filters). The first polarizer ( P 1 ) reduces the initial intensity I 0 by 2(0) , resulting in I 1 = I 0 . The light exiting P 1 is polarized along P 1 's axis. When this polarized light strikes the second polarizer ( P 2 ), the intensity is reduced by the projection of the electric field onto P 2 's axis. The final intensity ( I ) is thus given by I = I 1 2 , where is the angle between P 1 and P 2 . is the angle between the transmission axes of the two polarizers. I 0 is the intensity of the incident light before the first polarizer. Assuming the intensity reduction is linear with instead of 2 . Confusing the angle with the angle of incidence, or forgetting that is the angle between the polarizers' axes. Applying the formula to unpolarized light passing through only one polarizer (in which case I = I 0/2 ).