A slit of width $d$ is placed in front of a lens of focal length 0.5 m and is illuminated normally w

Question

A slit of width $d$ is placed in front of a lens of focal length 0.5 m and is illuminated normally with light of wavelength $5.89 	imes 10^{-7} \mathrm{~m}$. The first diffraction minima on either side of the central diffraction maximum are separated by $2 	imes 10^{-3} \mathrm{~m}$. The width $d$ of the slit is _______$	imes 10^{-4} m$ Report nearest integer.\

Professor PC Thomas Classes · Answer

Width of central maxima $=\frac{2 \lambda D}{d}$, during diffraction.\ or $\quad 2 	imes 10^{-3}=\frac{2 	imes\left(5.89 	imes 10^{-7}ight) 	imes 0.5}{d}$\ or $\quad d=2.945 	imes 10^{-4} \mathrm{~m}$.