A light of wavelength of $6×10^{-7} m$ illuminates a single slit of width 1.2 mm. The screen is at a distance of 2.4 m away from the slit. The width of central maximum is

2.4 mm

The correct answer is Option (1) → 2.4 mm

Given:

Wavelength, $\lambda = 6 \times 10^{-7} \ \text{m}$

Slit width, $a = 1.2 \ \text{mm} = 1.2 \times 10^{-3} \ \text{m}$

Distance to screen, $L = 2.4 \ \text{m}$

Width of central maximum in single slit diffraction: $w = \frac{2 \lambda L}{a}$

Substitute values:

$w = \frac{2 \cdot 6 \times 10^{-7} \cdot 2.4}{1.2 \times 10^{-3}} = \frac{2.88 \times 10^{-6}}{1.2 \times 10^{-3}} = 2.4 \times 10^{-3} \ \text{m}$

Width of central maximum: $w = 2.4 \ \text{mm}$