Content Curator
The physics constant values are synonymous to the physical constants sometimes universal constants or fundamental physical constants is the physical quantity or entity which are believed to have a constant value in time and they are universal also. Value of the physical constants is a fixed numerical value. These values do not involve directly in any of the measurements but they are the backbone in many calculations and applications.
These definite constant values aid the learning process by bringing down the potential to be spent on grasping the concepts. The physical constant also known as the fundamental constant or the universal constant is a physical quantity that is believed to be universal in nature and has a constant value at all times.
The topic has been included in the syllabus for the session 2021-22. In the revised syllabus of CBSE, so many topics have been omitted from this.
| Table of Content |
Keyterms: Fundamental physics, Constant value, universal constant, definite constant, fundamental constant, Electromagnetic interaction, Light
Value constants in physics: Introduction
[Click Here for Sample Questions]
The physical constants can take up many dimensional forms like the speed of light signifies a maximum speed for any object and the dimension and length of that object are divided by time; while the fine-structure physical constant α is dimensionless, which characterizes the strength of the electromagnetic interaction.
Also Read: Magnetic Quantum Number
Fundamental Constant Values in Physics
[Click Here for Sample Questions]
Speed of light in vacuum = c
Planck’s constant = h
The electric constant = ε0
The elementary charge = e
List of Constant Values in Physics
[Click Here for Sample Questions]
In physics, we deal with various dimensions. In order to set the dimensions of an entity, the time length of an event, or the density of the fluid we need to compare them with the other entities. It can be used as a reference. These entities are the constants of physics. There are many physical constants in science, some of the most widely recognized being the speed of light in vacuum c, the gravitational constant G, the Planck constant h, the electric constant ε0, and the elementary charge e etc.
For example, 6.02214 x 1023 mol-1 is the value of Avogadro's number, it remains the same everywhere.
Also Read:
| Related Articles | ||
|---|---|---|
| Avogadro's Number | Alpha Particle Mass | Laser |
Important Physical Constants Values
[Click Here for Sample Questions]
There are various fundamental physics constants that help us to describe the universe as completely as possible; a few are listed below in the table:
| S.No. | Name | Formula | Value |
|---|---|---|---|
| 1. | Von Klitzing constant | Rk = 2πh/e2 | 25812.80745...Ω |
| 2. | Curie constant | C = X (T - θ) | 1.3047 K * A/ (T * m) |
| 3. | Fine-structure constant | α = e2/2hcε0 | 0.007297351 |
| 4. | Compton wavelength | λ = h/mc | In meter: 2.42 x 10-12m In Angstrom = 0.242 Å |
| 5. | Impedance of free space | Z0 = 1/ε0c0 | 376.730...Ω |
| 6. | Bohr radius | a0 = 4πε0 h2/e2me | 0.0529 m |
| 7. | Faraday constant | F = eNA | 96,485 C/mol |
| 8. | Vacuum electric permittivity | ε0 = 1/μ0c2 | 8.854 x 10-12 F.m |
| 9. | Stefan–Boltzmann constant | σ = π2k4/60h3c2 | 5.67 x 10-8Js-1m-2K-4 |
| 10. | Thomson cross section | σe = (8π/3) re2 | 6.6524587321 x 10-29 m2 |
| 11. | Vacuum magnetic permeability | μ0 | 1.25663706212(19)x10-6N. A-2 |
| 12. | Reduced Planck constant | h = h/2π | 1.05457 x 10-34J. s |
| 13. | Josephson constant | KJ = 2e/h | 483597.84... x 108Hz. /V |
| 14. | Rest mass of the electron | me = 2R∞h/cα2 | 0.51099895000(15) Mev |
Famous Constant Values in Physics
[Click Here for Sample Questions]
There are so many constants besides those we mentioned above in the table, but some physics constants are recognized widely.
Constant values in physics that are most popular among all the physical constants are listed below in the table:
| S.No. | Name | Symbol | Value |
|---|---|---|---|
| 1. | Speed of light in the vacuum | c | 3 x 108 m/s |
| 2. | Planck’s constant | h | 6.62607015 x 10-34J. s |
| 3. | Gravitational constant | G | 6.673 x 10-11 Nm2/kg2 |
| 4. | Elementary charge | e, qe (charge of a proton) | 1.602176634 x 10-19 C |
| 5. | Electric constant | ε0 | 8.9875517923(14) x 109 kg.m³. s-4.A-2 |
| 6. | Alpha particle mass | mα | 6.644657230(82) x10-27 kg 4.001506179127(63) u 3.727379378(23) GeV/c2 |
| 7. | Deuteron mass | mD | 2.013553212745(40) u 1875.612928(12) MeV 1.67377 x 10-27kg or 1.67377 x 10-24g |
| 8. | Proton mass | mp | 1.672621898(21) x 10-27kg 1.672621898(21) x 10-24 kg 1.007276466879(91)u 938.2720813(58) MeV/c2 |
| 9. | Neutron mass | mn | 1.674927471(21) x 10-27 kg 1.674927471(21) x 10-24 g 1.00866491588(49) u 939.5654133(58) MeV/c2 |
| 10. | Electron mass | me | 9.10938356(11) x 10-31 kg 9.10938356(11) x 10-28g 5.48579909070(16) amu 0.5109989461(31) MeV/c2 |
| 12. | Boltzmann’s constant | Kb | 1.380649 x 10-23 J/K 1.380649 x 10-16erg/K |
| 13. | Gas constant | R | 8.3144598(48) J/K mol 8.3144598(48) x 103 amu.m2/s2K 8.3144598(48) x 10-2 L.bar/K mol 8.3144598(48) m3 .Pa/K.mol 62.363577(36) L.T or/K.mol 1.9872036(11) x 10-3Kcal/K.mol 8.2057338(47)x10-5m3.atm/K.mol 0.082057338(47) L.atm/K.mol |
Things to Remember
[Click Here for Sample Questions]
- Physical constants may take up many dimensional forms like the speed of light signifies a maximum speed for any object and the dimension
- Length of an object is divided by time while physical constant α is dimensionless which characterizes the strength of the electromagnetic interaction.
- In order to set the dimensions of an entity, the time length of an event, or the density of the fluid we need to compare them with the other entities
Sample Questions
Ques. Is μ a Physical Constant? (2 marks)
Ans. Yes, MU is a physical quantity. This physical constant is pronounced as mu naught or mu zero and it is represented as μ0. The μ0 is commonly known as the permeability of free space, vacuum permeability, the permeability of vacuum, or the magnetic constant. μ0 = 4π x 10-7H/m ≈ 12.57 x 10-7 H/m is the value of MU.
Ques. What are the Physical Quantities? Give Some Examples. (2 marks)
Ans. The quantities in physics that are measurable are known as the physical quantities. Such quantities include force, mass, velocity, light intensity and many others.
Ques. What are the two types of Physical Quantities? (1 mark)
Ans. The two types of Physical Quantities are fundamental or basic quantities and derived quantities.
Ques. How many constants exist as per modern physics? (2 marks)
Ans. The number of 19 independent fundamental physical constants is subject to change under possible extensions of the Standard Model, notably by the introduction of neutrino mass (equivalent to seven additional constants, i.e., 3 Yukawa couplings and 4 leptons mixing parameters).
Ques. What is the most important constant in physics? (1 mark)
Ans. Some of the most important and frequently used constants in physics such as the speed of light, Plank's constant, Earth acceleration and mass, etc.
For Latest Updates on Upcoming Board Exams, Click Here: https://t.me/class_10_12_board_updates
Do Check Out:
Comments