The distance a beam of light of wavelength 400 nm can travel without significant broadening if the a

Question

The distance a beam of light of wavelength 400 nm can travel without significant broadening if the aperture is 2 mm wide is\

Professor PC Thomas Classes · Answer

$\mathrm{Z}_{\mathrm{F}}=\mathrm{a}^{2} / \lambda=\frac{\left(2 	imes 10^{-3}ight)^{2}}{400 	imes 10^{-9}}=10 \mathrm{~m}$\