Question

A parallel beam of monochromatic light of wavelength 600 nm passes through single slit of 0.4 mm width. Angular divergence corresponding to second order minima would be ______ × \(10^{-3}\) rad.

Answer 1

Correct answer is : 6

\(\sin \theta \simeq \theta \simeq \frac{2 \lambda}{\mathrm{b}}\)

\(=\frac{2 \times 600 \times 10^{-9}}{4 \times 10^{-4}}=3 \times 10^{-3}\ \mathrm{rad}\)

Total divergence \(=(3+3) \times 10^{-3}=6 \times 10^{-3} \ \mathrm{rad}\)