Question

The value of Planck’s constant is ______
(A) $6.023\times {{10}^{-34}}$ Js
(B) $6.626\times {{10}^{34}}$ Js
(C) $6.626\times {{10}^{-34}}$ Js
(D) none of these

Answer 1

Hint: It is used in the evaluation of the value of energy , when energy of photons is to be calculated in photoelectric effect. It is a constant value.

Complete answer:
The value of Planck’s constant is theoretically known, it is $6.626\times {{10}^{-34}}$ .In the quantum of electromagnetism, Planck’s constant is a physical constant that relates the energy carried by single photon to its corresponding frequency or corresponding wavelength. Planck’s constant is defined as A fundamental constant, equal to the energy of a quantum of electromagnetic radiation divided by its frequency.
S.I unit of planck’s constant is joule second. And the MKS unit is in eV second. It is represented by h.
Planck’s constant was given by Max Planck’s. It was a part of his successful approach to produce a mathematical expression that accurately predicted the observed spectral distribution of thermal radiation from a closed furnace.
Planck’s constant is used in various applications including Planck’s equation. It is used in spectral radiation of a body in black body radiation, it is used in photoelectric effect, the famous planck’s Einstein relation, in atomic structure energy of nth orbit is given using planck’s constant. Planck’s constant is also used in uncertainty principle, in the relation of position and momentum. The matter wave equation expressed through the de-Broglie equation has Planck’s constant used in it.
So, the correct answer is “Option C”.

Note: Value of planck’s constant can be calculated using the slope of the graph with axis e is the electronic charge ($1.6022\text{ }\times \text{ }{{10}^{-19}}\text{ }C$) and c is the velocity of light($2.998\text{ }\times \text{ }{{10}^{8}}\text{ }m/s$).