A beam of light of λ = 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 first dark fringes on either side of the central bright fringe is
(a) 1.2 cm
(b) 1.2 mm
(c) 2.4 cm
(d) 2.4 mm
Correct option (d) 2.4 mm
Explanation:
Here, λ = 600 nm = 600 x 10-9 m
a = 1 mm=10-3 m,D=2 m
Distance between the first dark fringes on either side of the central bright fringe is also the width of central maximum.