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In a double-slit experiment, the seventh-order bright fringe is observed at an angle of 1.61°. If the slit separation is 0.10 mm, then what is the wavelength of the light? 1.40*10^-6m Submit Answer Incorrect. Tries 4/20 Previous Tries e Post Discussion 4 Send Feedback

Answer 1

---- - W ST - - - - E2 . . - .. - - - Yy20 19.7-5 امر 2 bet E., & be the wavefronts from slits interferire at point p at height y as shown. S₂ B is the path difference let it be ax. for constructive interference, An n a , hao, 1, 2, 3,... n corresponds to order of the interference pattern. for destructive Interference, ana (nt tall. . Now, since D»d, the sip, sup and QP are parallel cappronimated). Hence sig is perpendicular to not only sup but also to Sip ond Szp.

Consider the tollowits. 70.de --- 2920; 258990; .,91 g S9o'= 90-0 . Sinos S2B (: ad'=s8 since d ga' is parallel to SaB). 1. -0. finde en Also from o pay Tomo - from diagram and .- @ and deLD for small sino o will be small Tamo Sino ~ angles Wand . - A a Z - ③ from

Given ! n= 7; d = o.1 mm = 1x0"m. 02 1.61°. From O, sino - Am . Seventh order ana nx= 770 brishet & fringe) =) naa d sino dfino 1x104x fin(1.61) 2) da 3 4.0137 X10-*m = 401.37 hm