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

(1) 1.2 mm

(2) 1.2 cm

(3) 2.4 cm

(4) 2.4 mm

(4) Distance between the first dark fringes on either side of central maxima = width of central maxima = $\frac{2\lambda D}{d}$ = $\frac{2×600×{10}^{-9}×2}{1×{10}^{-3}}$ = 2.4 mm.

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