Mm. the a convex lens fraunhofer diffraction pattern is observed on a screen which is placed at the focal plane of a con whose focal length is 20 cm. calculate

mm. The a convex lens Fraunhofer diffraction pattern is observed on a screen which is placed at the focal plane of a con whose focal length is 20 cm. Calculate the distance between the first two minima and the fret maxima on the screen. Assume = 5 x 103 cm and that the lens is placed very close to the elit Example: A parallel beam of light in incident normally on a narroW slit of width 02 m the first two