Question

1. 730 nm light is incident on two narrow, vertical slits of that are 0.43 mm apart. On a screen 4.0 m away, a horizontal pattern of light and dark appears. Describe (and/or draw a diagram) the pattern near the centerline (say, within 10 cm of the point the light would have hit if there were no slits) and calculate the dimensions of the major features of the pattern.

Answer 1

Question giveni = 7300m=730x10 m (Seit sepsution) da 0.43 mm2 4.3x104 Seit to scree distance = 4 m concept - Led two vessiccel seits, and S2 Shawnin given fig. 0 LEI G Х woo w wo wo is 1. X+ A d -L R 21 for analysis post we make a ray diagreem. det a noth order fringe is obdelined cet e dhon path difference af beth say S, and Sz reaching at P CX+ DX – XC) = 0x and from our geometry ax=S₂ A From A SIS₂ A S2A Si Sasino (S2A = dsino iso is small then dsino a dtano and dtano = dyn ssimo from Đ then sino tamo SA= sopol tom o= = In

how Toxa D - For bright fringe ni (1) Xez dyn D ni lon= h. 10 m -whore n = 0, 1,2... bright ofringe obtelined at G= 0, & ld,h 200 d & tire sign for above contredine and five sigh for below Centre line} . For dark fringe path difference should be odd melltiple of 1/2 Mears Ax= (n+22) 1/2 liv where n=0, 1, 2, then from and (iv) 190 d mean deurk fringe oblecited as y = - DAd + 3DA in our cuse da 0193xros = 4m d= 730x10m dren position of first bright fringe ofler fhan Pontale centrel bright y = (0) (4xx 730x109 m) 0.434103 y = 679 0.6 X 106 y = 679 80"} I 501 24 0.43mm 6.8mm

room from Since we have to give Central eine (1-10 loch - 100mm sinee y = 6.8mm - 14.7 10 con coch below 1 hence. in 100 mm these will be total loo Clo take integer 6.8 valle. 14 bright fringe if we consider above and the (4 bright are observed above and 14 bright below excluding bentore bright then iy ieithi loom oney 7 fring above to con treel bright and 7 below to centrel bright denue including centell bright resell is fringe observed since est dark obsted as y = od Centre and second dorld at - fringe width Dopo lochar then within 100mm total s observed. {7 abue Central line nd 7 below benofeel line: Bloom iftotel 301 (4 dark fringes 2d 6.8mm (See abue 14 dark fringe