Question

When white light is used to illuminate the two slits in young's experiment, certain wavelengths are missing?

Answer 1

Let nth fringe is missing , itss distance from the centre of the screen

Y = (2n+1)λ*d/ 2b

since , the point is infront of slit its distance from centre , Y=b/2

b/2 = (2n+1)λ*d / 2b

λ= b2 / (2n+1) d , & for n=1 , λ= b2/3d ...So , it must be (b)

Answer 2

Answer:

The separation between the slits is b and the screen is at a distance `d(gtgtb)` from the slits. At a point on the screen directly in front of one of the slits, certain wavelengths are missing. Some of these missing wavelength are `(a) lambda = b^2//d (b) lambda=2b^2//d (c) lambda = b^2//3d (d)lambda = 2b^2//3d