NTA Abhyas JEE Main2020PhysicsWave OpticsPractice
Two plane mirrors are placed parallel to each other at a distance 4 d as shown in the figure. The point source of light S is having wavelength equal to λ . The light is reaching the screen (right of the source) only after reflection. For point P to be 2nd maxima, the value of λ 2 = K d 2 D . Where K is an integer. Find value of K ? (assume D ≫ d and d ≫ λ )
Options
- A6
- B2
- C3
- D4
Correct answer
A. 6
Step-by-step solution
At P: Path difference ∆ x = 8 d × 3 d D For 2 n d maxima ∆ x = 2 λ = 24 d 2 D ; λ = 12 d 2 D λ 2 = 6 d 2 D = k d 2 D ⇒ k = 6