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# Two slit in a young's double slit experiment is separated by a distance d. The screen distance is D and it is illuminated by a light of wavelength $\lambda$. A point 0 on the screen is $\large\frac{2d}{3}$ distance from the point which is directly in front of one of the slits. How far away is 0 from the central bright fringe.

$(a)\;\frac{d}{2} \\ (b)\;\frac{d}{3} \\ (c)\;2d \\ (d)\;\frac{d}{6}$

The central bright fringe is $\large\frac {d}{2}$ from the point directly in front of one of the slit.
$\therefore$ distance between central bright fringe and 0
$ie \large\frac{2d}{3} -\frac{d}{2}$
$\qquad =\large\frac{d}{6}$
Hence d is the correct answer.