KVPY2017PhysicsWave Optics
Two circularly shaped linear polarisers are placed coaxially. The transmission axis of the first polarizer is at 30^ from the vertical while the second one is at 60^ , both in the clockwise sense. If an unpolarised beam of light of intensity I =20 ~W / m ² is incident on this pair of polarisers, then the intensities I ₁ and I ₂ transmitted by the first and the second polarisers, respectively, will be close to
Options
- AI ₁=10.0 ~W / m ² and I ₂=7.5 ~W / m ²
- BI ₁=20.0 ~W / m ² and I ₂=15 ~W / m ²
- CI ₁=10.0 ~W / m ² and I ₂=8.6 ~W / m ²
- DI ₁=15.0 ~W / m ² and I ₂=0.0 ~W / m ²
Correct answer
A. I ₁=10.0 ~W / m ² and I ₂=7.5 ~W / m ²
Step-by-step solution
aligned I ₀ &=20 ~W / m ² I ₁ &= I ₀ 2 = 20 2 =10 ~W / m ² I ₂ &= I ₁ ² 30^ &=10 ( 3 2 )²=10 . 3 4 &=7.5 w / m ² aligned