IIT JEE , AIEEE Forum - Physics , Optics

AAKRITI

(a)

wavelength to be absent, it should be a dark fringe

d,D,y all are given

in y1 ( putting n=0,1,2..)

for n=1, lambda is coming 667 nm

for n= 2, lambda is coming 400nm

(b)

wavelengths with strong intensity will be bright fringes

d,D,y are given

in y ( = n.lambda.D/d) put n=1,2

for n=1, lambda = 100nm ( not possible)

for n=2 lambda = 500nm

such questions are really simple, just understand the ydse

and all the derivations of the formulae,

you will get each answer right

and in this question, you didn,t need to post the diagram

its clear from the question itself ;)