KVPY2020PhysicsWave Optics
A camera filled with a polarizer is placed on a mountain, in a manner to record only the reflected image of the sun from the surface of a sea as shown in the figure. If the sun rises at 6 . 00   AM and sets at 6 . 00   PM during the summer, then at what time in the afternoon will the recorded image have the lowest intensity, assuming there are no clouds and intensity of the sun at the sea surface is constan
Options
- A12 . 32   PM
- B3 . 32   PM
- C5 . 00   PM
- D6 . 00   PM
Correct answer
B. 3 . 32   PM
Step-by-step solution
Camera will receive minimum intensity when. Light will incident at Brewsters's angle. ∴ tan i = μ = 4 / 3 ⇒ i = 53 ° time taken by sun to go from A to P will be 12 hr 180 ° × 143 ° = 9 . 53 hr = 9 hr 32   min . ∴ time = 6   AM + 9   hr   32   min ⇒ 3 : 32   PM