Question

In young's double slit experiment the two slits 0.15mm apart are illuminated by monochromatic light of wavelength 450nm. The screen is 1m away from the slits. Find the distance of the second



a.Bright fringe



b.Dark fringe from central maximum

Answer 1

Given d = 0.25mm = 0.15 x 10-3m,  

λ = 450nm = 450 x 10-9m, D =1.0m  

(a) Distance of second bright maximum from central maximum (n = 2)

      Refer Image 1

b) Distance of second dark fringe from central maximum (n =2)

      Refer image 2

Hope it helps;)