COMEDK2021PhysicsWave Optics
An unpolarised beam of intensity I₀ is incident on a pair of nicols making an angle of 60^ with each other. The intensity of light emerging from the pair is
Options
- AI₀
- BI₀ 4
- CI₀ 2
- DI₀ 8
Correct answer
D. I₀ 8
Step-by-step solution
When an unpolarised beam of intensity I₀ passes through the first nicol (polarizer), the intensity of the emerging light is reduced to half of the incident intensity. I₁ = I₀ 2 The light emerging from the first nicol is plane-polarized. This light then passes through the second nicol (analyzer), which is at an angle = 60^ with respect to the first nicol. According to Malus Law, the intensity of the light emerging from the analyzer is given by I = I₁ ²( ) . Substituting the values I₁ = I₀ 2 and = 60^ : I = I₀ 2 ²(60