Question

Draw the intensity pattern for single slit diffraction and double slit interference. Hence state two differences between interference and diffraction patterns.

Answer 1

The main differences between Interference and Diffraction are:

1. Interference occurs when 2 separate wavefronts originate from 2 coherent sources, whereas diffraction occurs when the secondary wavelets originate from different parts of the same wavefront.
   
2. In Interference, the region of minimum intensity is perfectly dark, whereas in diffraction it is not perfectly dark.
   
3. In Interference, the width of the fringes is equal, whereas in diffraction it is never equal.