A Fraunhofer diffraction pattern due to a narrow slit is obtained on a screen placed at a distance (D ) from the slit whose slit width is (a ). The distance of first secondary maximum from the central maximum is

Step-by-step solution

In Fraunhofer diffraction pattern, the direction of secondary maximum is given as ( aligned & =(2 n+1) 2 a =(2 1+1) 2 a & = 3 2 a aligned ) ( ) Distance of first secondary maximum from the central maximum is given by (x= D= 3 2 a D= 3 D 2 a )