Two slits in Young's double slit experiment are 1.5 mm apart and the screen is placed at a distance

Question

Two slits in Young's double slit experiment are 1.5 mm apart and the screen is placed at a distance of 1 m from the slits. If the wavelength of light used is $600 	imes 10^{-9} \mathrm{~m}$ then the fringe separation is

Professor PC Thomas Classes · Answer

(d): Slit separation distance, $d=1.5 \mathrm{~mm}=1.5 	imes 10^{-3} \mathrm{~m}$ Slit and screen separation distance, $D=1 \mathrm{~m}$ Wavelength, $\lambda=600 	imes 10^{-9} \mathrm{~m}$ Fringe separation $=\frac{\lambda D}{d}=\frac{600 	imes 10^{-9} 	imes 1}{1.5 	imes 10^{-3}}=4 	imes 10^{-4} \mathrm{~m}$