KVPY2017PhysicsWave Optics
Three circularly shaped linear polarisers are placed coaxially. The transmission axis of the first polariser is at 30^ , the second one is at 60^ and the third at 90^ to the vertical all in the clockwise sense. Each polariser additionally absorbs 10 % of the light. If a vertically polarised beam of light of intensity I =100 W / m ² is incident on this assembly of polarisers, then the final intensity of the transmitte
Options
- A10 ~W / m ²
- B20 ~W / m ²
- C30 ~W / m ²
- D50 ~W / m ²
Correct answer
C. 30 ~W / m ²
Step-by-step solution
I ₁= I ₀ 0.9 ² 30^ = I ₀ 0.9 3 4 I ₂= I ₁ 0.9 ² 30^ = I ₁ 0.9 3 4 I ₃= I ₂ 0.9 ² 30^ = I ₂ 0.9 3 4 I ₃= I ₀(0.9)³ ( 3 4 )³ I ₃=30.75 w / m ²