A monochromatic beam passes through a single, narrow rectangular slit and produces a diffraction pattern on a distant screen.
(i) Explain qualitatively how the angular width of the central diffraction maximum depends on the slit width and on the wavelength of the light used.
(ii) Using the reasoning in part (i), predict and justify what happens to the angular width of the central maximum when
(a) the slit width is reduced to one-half of its original value while the wavelength remains the same, and
(b) the wavelength of the light is doubled while the slit width remains unchanged.