Question

What is the physical significance of the Planck’s constant?

Answer 1

Hint: The Planck constant is the fundamental physical constant denoted by $h$, and has fundamental importance in quantum mechanics. Hence because of mass-energy equivalence, the Planck constant is related to frequency.

Complete answer:
Planck's constant was made to play a major role in many aspects of quantum physics. Now it has become one of the most important universal constants in the world of physics. Planck’s constant tells about the behaviour of the particles and the waves on the atomic scale, including the particle aspect of light. Planck’s constant is discovery because of the concept that energy can be expressed in discrete units or quantized, this proved fundamental for the development of quantum mechanics.
Let us take an example of a glass of water; it contains an astonishing amount of water molecules, we can say that the smallest unit of water is water molecule. Assume that energy behaves in the same manner; it comes in “smaller units”. Planck's constant connects a particle frequency with its total energy.
 For explaining black-body radiation, Planck proposed that the radiation energy is transmitted in discrete packets termed as “energy quanta”. After that Einstein later found that the energy of light absorbed by an electron is also in small packets which is the same as Planck’s energy quanta, and is proportional to the light frequency $\nu $. This relation is also known as Planck-Einstein relation:
$E = h\nu $
Where, $E$ is the energy of light, $h$ is the Planck’s constant, i.e. $6.6262 \times {10^{ - 32}}J$ and $\nu $is the frequency of the light.
Planck’s constant is very much significant, as the radiation, such as light which is emitted, transmitted and absorbed in discrete packets of energy or quanta which is determined by the frequency of the radiation and the value of the Planck’s constant.

Note:
Each quantum or photon’s energy $E$ is equal to Planck's constant $h$ times the radiation frequency which is denoted by the Greek letter $nu$, $\nu $or simply by $E = h\nu $. The modified version of Planck’s constant is known as $h - bar(h)$ or the reduced Planck’s constant, in which \[h\] is equal to \[h\] divided by $2\pi $, is the quantization of angular momentum.