Question

Fraunhofer diffraction pattern is observed at a distance of $2m$ on screen, when a plane wavefront of $6000\mathring{A}$ is incident prependicularly on $0.2mm$ wide slit. Width (in $mm$) of central maxima is ?

Answer 1

Answer: 12.00

$w=\frac{2f\lambda }{a}=12mm$