Question

A pair of closely spaced slits is illuminated with 626.0-nm light in a Young's double-slit experiment. During the experiment, one of the two slits is covered by an ultrathin heavy flint glass plate with index of refraction n = 1.890. What is the minimum thickness of the heavy flint glass plate that produces a dark fringe at the center of the viewing screen?

______________nm

Answer 1

at Due to enserting the flint at Slit, path difference central pointra will not be zero, At Central point path difference will be ni refraxive index, of ti thickness h(t) glass. At Central maxima; = nitt). A = (2+2) A Fornal Ist dark finge. t(n-1) Given : x = 626 nm. = 1,890. t= a {(n-1) t = 6.26x10-9 241.890-1) ta 3.517x107m t=351078 nm