Four polaroids are placed at an angle with the optic axis of the preceding one. If unpolarised light of intensity 'I' falls on the first polaroid, the intensity of light transmitted from the fourth polaroid is [ = X]

Step-by-step solution

Intensity of the incident unpolarised light is I . When unpolarised light passes through the first polaroid, the transmitted intensity becomes half of the initial intensity. Thus, the intensity after the first polaroid is: I₁ = I 2 According to Malus's law, when polarised light of intensity I₀ passes through a polaroid placed at an angle with the plane of polarisation, the transmitted intensity is I₀ ^2 . Intensity after passing through the second polaroid: I₂ = I₁ ^2 = I 2 ^2 Intensity after passing through the th