How does the angular separation between frings in single-slit diffraction experiment change when the distance of separation between the slit and screen is doubled ?

Explanation

The angular width of central diffraction band `=(2lamda)/(a)alpha=(1)/(a).` When slit width is doubled the width of central band becomes half of the initial value. As intensity of central maximum `alphaa^(2)`, if slit width is doubled, the intensity become four times.