Wave Optics

JEE Main level, single correct, medium

104 of 191

Question 104 of 191

In a young's double slit experiment, the slits are placed 0.320mm0.320mm apart. Light of wavelength λ=500nm\lambda =500nm is incident on the slits. The total number of bright fringes that are observed in the angular range −30o≤θ≤30o-{30}^{o}\leq \theta \leq {30}^{o} is:

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Answer: (B) 641

dsinθ=nλdsin\theta =n\lambda

n=0.320×10−3×12500×10−9n=\dfrac{0.320\times {10}^{-3}\times \dfrac{1}{2}}{500\times {10}^{-9}}

=320=320

Hence number of maxima =320×2+1=641=320\times 2+1=641

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