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Two coherent narrow slits emitting light...


Two coherent narrow slits emitting light of wavelength `lamda` in the same phase are placed parallel to each other at a small separation of `3lamda` the light is collected on a screen S which is placed at a distance `D(gt gt lamda)` from the slits the smallest distance x such that the P is a maxima.

A

`sqrt(3D)`

B

`sqrt(8)D`

C

`sqrt(5)D`

D

`sqrt(5)(D)/(2)`

Text Solution

Verified by Experts

The correct Answer is:
B

In this case path difference is d `costheta`.
so `nlamda=lamda=3lamdacosthetaimpliescostheta=(1)/(3)`
`implies(D)/(sqrt(D^(2)+y^(2)))=(1)/(3)implies3D=sqrt(D^(2)+Y^(2))`
`impliesy=sqrt(8)D=2sqrt(2)D`
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ALLEN-WAVE OPTICS-Exercise 1 (Check your Grasp)
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  13. Phenomenon of diffraction occurs

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  15. which of the following any gives more distinct diffraction

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  16. All fringes of diffraction are of-

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  17. A single slit of width d is placed in the path of beam of wavelength l...

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  18. Direction of the first secondary maximum in the Fraunhofer diffraction...

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