Question

What is maxima and minima in diffraction?

Answer 1

Hint: We are asked to define the terms maxima and minima with respect to diffraction. In order to do this, we start by defining the process of diffraction, its conditions and then we define the asked terms stating the conditions for their existence as well. We can also add the formula to find the maxima and minima of a certain diffraction pattern.

Formula used:
The formula used to find the maxima of a diffraction pattern is given as, $$d\sin \theta =m\lambda$$
The formula used to find the minima of a diffraction pattern is given as, $$d\sin \theta =\left(m+{\displaystyle \frac{1}{2}}\right)\lambda$$, Where $m$ is a whole number

Complete answer:
Let us start by defining the process of diffraction and stating the conditions.
Diffraction: In simple words, diffraction is just the bending of light. When light waves come in contact with an obstacle, it tends to bend and move around the object creating a pattern known as the diffraction pattern where there are light and dark colored bands.
Conditions for diffraction: (A) the source of light used for diffraction must be monochromatic. Monochromatic means that the light should be of single wavelength or frequency.
(B) The source of the light should have a comparable wavelength with the size of the obstacle or object.

Maxima: It is the point where two crests or troughs of two different wavefronts meet.
The formula for maxima is given by $$d\sin \theta =m\lambda$$
Minima: It is the point where a crest and a trough of two different wavefronts meet.
The formula for minima is given by $$d\sin \theta =\left(m+{\displaystyle \frac{1}{2}}\right)\lambda$$

Note:
An important point to be remembered is that the width of the slit must be comparable or as the same order of magnitude as the wavelength of the incident monochromatic source light.