Question

Write down two basic differences between interference and diffraction.

Hint:

Interference = Superposition of waves from two coherent sources. Diffraction = Spreading of light around obstacles or slits.

Answer 1

Interference and diffraction are both wave phenomena that involve the interaction of light waves, but they have distinct differences. The two main differences are:
1. Nature of the Phenomenon: - Interference occurs when two or more waves meet and combine, resulting in constructive or destructive interference. The waves interfere with each other, creating regions of high and low intensities depending on their phase relationship. - Diffraction, on the other hand, refers to the bending of light waves around obstacles or through narrow openings. It occurs when light encounters an obstacle or slit that is comparable in size to its wavelength, causing the light to spread out and form diffraction patterns. 2. Occurrence: - Interference is typically observed when two coherent sources of light are involved. Coherent sources have a constant phase relationship, and interference is a result of the superposition of these two sources.
- Diffraction occurs due to a single light source passing through an opening or around an obstacle. It doesn't require two sources and is instead caused by the nature of the wave and the size of the obstacle or aperture.
In summary, interference involves the interaction of two or more coherent waves, while diffraction is the spreading of a single wave around obstacles or through slits.