A beam of light of wavelength 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between the first dark fringes on either side of the central bright fringe is

Given, λ=600 nm=6×10−7m          a=1mm=10−3 m, D=2 mDistance between the first dark fringes on either side of central bright fringe = width of central maximum                                                                                                                       =2λDa=2×6×10−7×210−3=24×10−4 m=2.4mm