A parallel beam of monochromatic light is incident normally on a slit. The diffraction pattern is ob

Question

A parallel beam of monochromatic light is incident normally on a slit. The diffraction pattern is observed on a screen placed at the focal plane of a convex lens. If the slit width is increased, the central maximum of the diffraction pattern will\

Professor PC Thomas Classes · Answer

D)Width of central maximum in diffraction pattern $=\beta$\ $\beta=\frac{2 \lambda D}{a}$ As slit with a is increased, $\beta$ decreases i.e. the central maximum becomes narrower. As the same energy is distributed over a smaller area, the central maximum becomes brighter.\