Question
Physics Question on Wave optics
In the Young's double slit experiment using a monochromatic light of wavelength λ the path difference (in terms of an integer n) corresponding to any point having half the peak intensity is
A
(2n+1)2λ
B
(2n+1)4λ
C
(2n+1)8λ
D
(2n+1)16λ
Answer
(2n+1)4λ
Explanation
Solution
2Imax=Imcos2(2ϕ)
⇒cos(2ϕ)=21
⇒2ϕ=4π
⇒ϕ=2π(2n+1)
⇒Δx=2πλϕ
=2πλ×2π(2n+1)
=4λ(2n+1)