Two slits of width \(2 \mu \mathrm{m},\) each in an opaque material, are
separated by a center-to-center distance of \(6 \mu \mathrm{m}\). A
monochromatic light of wavelength \(450 \mathrm{nm}\) is incident on the double-
slit. One finds a combined interference and diffraction pattern on the screen.
(a) How many peaks of the interference will be observed in the central maximum
of the diffraction pattem?
(b) How many peaks of the interference will be observed if the slit width is
doubled while keeping the distance between the slits same?
(c) How many peaks of interference will be observed if the slits are separated
by twice the distance, that is, \(12 \mu \mathrm{m}\), while keeping the widths
of the slits same?
(d) What will happen in (a) if instead of 450-nm light another light of
wavelength \(680 \mathrm{nm}\) is used?
(e) What is the value of the ratio of the intensity of the central peak to the
intensity of the next bright peak in (a)?
(f) Does this ratio depend on the wavelength of the light?
(g) Does this ratio depend on the width or separation of the slits?