NTA Abhyas JEE Main2020PhysicsWave OpticsPractice
In YDSE apparatus as shown in figure wavelength of light used in λ . The screen is moved away from the source with a constant speed V. Initial distance between screen and plane of slits was D . Suppose P is the point where 5 t h order maxima was lying at t = 0 , then after how much time third-order maxima will lie at this point P on that screen?
Options
- A2 D V
- B2 D 3 V
- C3 D 2 V
- D3 D V
Correct answer
B. 2 D 3 V
Step-by-step solution
At t = 0 ,   Δ x = 5 λ = y d D .....(i) After t times Δ x 1 = 3 λ = y d D + v t ......(ii) Dividing (i) and (ii) we get 5 3 = D + v t D 5 D = 3 D + 3 v t 2 D = 3 v t     ⇒     t = 2 D 3 v