Wave Optics

JEE Main level, single correct, medium

94 of 191

Question 94 of 191

In a Young's double slit experiment,1616 fringes are observed in a certain segment of the screen when light of wavelength 700nm700nm is used. If the wavelength of light is changed to 400nm400nm, the number of fringes observed in the same segment of the screen would be :

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Answer: (D) 2828

y=m1Dλ1d=mDλ2dy=\dfrac{{m}_{1}D{\lambda }_{1}}{d}=\dfrac{mD{\lambda }_{2}}{d}
m2m1=λ1λ2⇒m2=700400×16=28\dfrac{{m}_{2}}{{m}_{1}}=\dfrac{{\lambda }_{1}}{{\lambda }_{2}}\Rightarrow {m}_{2}=\dfrac{700}{400}\times 16=28

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