CBSE Class 12-science Answered

Diffraction is the phenomenon of bending of light around the corners of small apertures or obstacles and its spreading into the region of the geometrical shadow.

The intensity distribution wave for diffraction is shown in the above figure.

In interference, all bright fringes are of same intensity. In diffraction, the intensity of bright fringes decreases with the increase in distance from the central bright fringe.

(i) When the width of the slit is decreased, the diffraction pattern becomes pronounced.

(ii) When monochromatic source is replaced by white light source, we get a coloured diffraction pattern. The central band is white, but the other bands are coloured.As band width is proportional to λ,  the red band of higher wavelength is wider than the violet band with smaller wavelength.