Q.
A narrow slit of width 2mm is illuminated by monochromatic light of wavelength 500nm. The distance between the first minima on either side on a screen at a distance of 1m is
Here, a=2mm=2×10−3m λ=500nm=500×10−9m=5×10−7m,D=1m
The distance between the first minima on either side on a screen =a2λD=2×10−32×5×10−7×1 =5×10−4m =0.5×10−3m =0.5mm