Question

Write five differences between interference and diffraction.

Answer 1

Interference and diffraction are phenomenons shown by waves in which waves superimpose to give bright and dark fringes throughout the screen. An apparatus is used in which a slit or double slit is kept at a distance from the screen and waves are made to superimpose on the screen.

Complete answer:

Interference	Diffraction
Interference is a phenomenon in which two waves from different but coherent sources superimpose to form low, high or same amplitude.	Diffraction is a phenomenon in which waves bend around obstacles to spread in space through an aperture.
In interference, the fringe width is always equal while in diffraction, the fringe width is varying.	When diffraction occurs, the path of the wave changes or the direction of propagation changes as the bending of the wave around an obstacle occurs while in interference, the wave travels in the same path.
The points minimum intensity in diffraction are not completely dark whereas in interference, completely bright and dark points of maximum and minimum intensity are formed respectively.	The spacing between fringes is uniform throughout in interference while in diffraction, the spacing between the fringes is non-uniform.
The sources are referred to as interference sources if the number of sources is as few as two sources	If the number of sources is more than to the sources are referred to as diffraction sources.
It is absolutely dark in the region of minimum intensity, in the case of interference.	We see a variance in the intensity of interference in diffraction.

Note:
Coherent sources are those sources which have same frequency and a constant phase difference between them. A slit or obstacle is important for diffraction to take place. In diffraction fringes are formed from a single wavefront while interference takes place by the superposition of wavefronts from two different light waves.