Fundamental Physical Constants
- table or chart of the electrical and physical constants used in a variety of ways including
in electronics design.
Physical & fundamental constants pages include:
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•
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Fundamental physical constants
Universal constants
Electromagnetic constants
Atomic constants
Electron constants
Proton constants
Neutron constants
Physico-chemical constants
There is a large number of physical constants and fundamental that are used in physics and electronics engineering.
These constants can be used in a variety of electronics calculations and may be very useful on occasions. Although not widely used in electronics design,
they may nevertheless be used on occasions.
A physical constant is a quantity that is generally believed to be universal in nature and constant over time. In other words, apart from improvements in
measurement accuracies, it will remain the same.
These physical constants appear in many areas of science and they take many forms.
Common examples of some fundamental physical constants are the speed of light in a vacuum and it has the dimensions of speed, i.e. length divided by
time. Other physical constants have different dimensions, or some can be dimensionless.
Physical constant groupings
In order to be able to refer to the different physical constants and fundamental constants more easily, we have split them into different groups as seen
below:
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Universal constants: Universal constants are those which are used in many areas of science. They include some of the fundamental constants
such as the speed of light, permittivity and permeability in a vacuum, gravitational forces and Planck's constant. Read more . . .
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Electromagnetic constants: The electromagnetic constants are those constants within the overall physical constants that pertain to
electromagnetic aspects. They include such items as the elementary charge, magnetic flux quantum, the Josephson frequency-voltage quotient and
the like. Read more . . .

Atomic constants: There are many fundamental physical constants associated with atomic level physics, etc. These atomic constants include
values such as Rydberg constant, Bohr radius, Hartree energy, etc Read more . . .
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Electron constants: There are many physical or fundamental constants associated with electrons. These electron constants include values such
as electron specific charge, electron molar mass, electron specific charge, etc. Read more . . .

Proton constants: These physical constants are applicable to proton characteristics and include characteristics such as proton mass, proton
specific charge, proton molar mass, proton magnetic moment etc. Read more . . .

Neutron constants: These physical constants are related to neutrons, and include parameters such as neutron mass, neutron-electron mass ratio,
neutron molar mass, etc.. Read more . . .
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Physicochemical constants & parameters: These physical constants include parameters related to physic-chemical characteristics and include
items such as Avagadro constant, Faraday constant, Boltzmann constant, standard atmosphere and many more. Read more . . .

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
Universal Constants
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- table or chart of universal physical constants including symbol, value and units for
values such as speed of light, permittivity, etc
Physical & fundamental constants pages include:
•
•
•
•
•
•
•
•
Fundamental physical constants
Universal constants
Electromagnetic constants
Atomic constants
Electron constants
Proton constants
Neutron constants
Physico-chemical constants
The universal constants are physical constants that are widely used in science.
The physical constants that come under the universal constants heading include items such as the speed of light, permeability of a vacuum, permittivity of a
vacuum, Planck's constant and the Newtonian constant of gravity.
Details for these universal constants and more are given below. The constant name, symbol, value, units and the relative uncertainty are provided.
CONSTANT NAME
SYMBOL OF
CONSTANT
VALUE
Speed of light in vacuum
c
Permeability in a vacuum
µ0
299 792 458
4π x 10^-7
= 12.566 370 614
Permittivity in a vacuum
ε0
1/(µ0 ⋅ c^2)
8.854 187 817
Newtonian constant of gravitation
G
6.672 59
Planck constant
h
Planck's constant
in electron volts
h/{e}
UNITS
RELATIVE
UNCERTAINTY
m/s
N ⋅ A^-2
10^-12 F &sdot
m^-1
10^-11 m^3 kg^-1
s^-1
128
6.626 0755
10^-34J⋅ s
0.60
4.135 6692
10^-15 eV s
0.30
10^-34 J s
0.60
10^-16 eV s
0.30
h/2π
1.054 572 66
h/2π in electron volts
6 582 1220
Planck mass
mp
2.176 71
10^-8 kg
64
Planck length
lp
1.616 05
10^-35m
64
Planck time
tp
5.390 56
10^-44s
64
Electromagnetic Constants
- table or chart of electromagnetic constants including symbol, value and units for values
such as elementary charge, magnetic flux quantum, Josephson frequency voltage
quotient, etc.
Electromagnetic constants are used in many areas of science and electronics for a variety of calculations.
The electromagnetic constants that come under the universal constants heading include items such as the elementary charge, magnetic flux quantum,
Josephson frequency voltage quotient, etc.
Details for these electromagnetic constants and more are given below. The constant name, symbol, value, units and the relative uncertainty are provided.
CONSTANT NAME
SYMBOL OF
CONSTANT
VALUE
UNITS
RELATIVE
UNCERTAINTY
Elementary charge
e
1.602 177 33
10^-19 C
0.30
Elementary charge
e/h
2.417 988 36
10^14 A J^-1
0.30
Magnetic flux quantum
φ0
2.067 834 61
10^-15 Wb
0.30
10^14 Hz V^-1
0.30
Josephson frequency-voltage quotient
2e/h
4.835 9767
Quantised Hall conductance
e^2/h
3.784 046 14
RH
25.812 8056
Ω
0.045
Bohr magneton
µB
9.274 0154
10^-24 J T^-1
0.34
Nuclear magneton
µN
5.050 7866
10^-27 J T^-1
0.34
Quantised Hall resistance
0.045
Atomic Constants
- table or chart of atomic constants including symbol, value and units for values such as
Rydberg constant, Bohr radius, Hartree energy, etc.
Atomic constants are used in many areas of science and electronics for a variety of calculations.
The atomic constants that come under the universal constants heading include items such as the Rydberg constant, Bohr radius, Hartree energy, etc.
Details for these atomic constants and more are given below. The constant name, symbol, value, units and the relative uncertainty are provided.
CONSTANT NAME
SYMBOL OF
CONSTANT
Rydberg constant
R
VALUE
UNITS
RELATIVE
UNCERTAINTY
10.973 731 534
m^-1
0.0012
Rydberg constant in hertz
3.289 841 9499
10^15 Hz
0.0012
Rydberg constant in Joules
2.179 8741
10^-18 J
0.60
Rydberg constant in eV
eV
0.30
Bohr radius
a0
13.605 6981
0.529 177 249
10^-10 m
0.045
Hartree energy
Eh
4.359 748 2
10^-18 J
0.60
27.211 396 1
eV
0.30
α
7.297 353 08
10^-3
0.045
α^-1
137.035 989 5
Hartree energy in eV
Fine structure constant
Inverse fine structure constant
0.045
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Electron Constants
- table or chart of electron constants including symbol, value and units for values such as
electron specific charge, electron molar mass, electron specific charge, etc.
Electron constants are used in many areas of science and electronics for a variety of calculations.
The electron constants that come under the universal constants heading include items such as the electron specific charge, electron molar mass, electron
specific charge, etc.
Details for these electron constants and more are given below. The constant name, symbol, value, units and the relative uncertainty are provided.
CONSTANT NAME
Electron mass
SYMBOL OF
CONSTANT
Me
Electron mass in electron volts
Electron-proton mass ratio
Electron α particle mass ratio
VALUE
9.109 389 7
UNITS
RELATIVE
UNCERTAINTY
10^-37 kg
0.59
0.510 999 06
MeV
0.30
me/mp
5.446 170 13
10^-4
0.02
me/m&almpga;
1.370 933 54
10^-4
0.021
Electron specific charge
-e/me
-1.758 819 62
10^11 C kg^-1
0.30
Electron molar mass
M(e)
5.485 799 03
10^-7 kg/mol
0.23
λc
2.426 310 58
10^-12 m
0.089
Classical electron radius
re
2.817 940 92
10^-15 m
0.13
Thomson cross section
σe
0.665 246 16
10^-28 m^2
0.27
µe
928.477 01
10^-26 J T^-1
0.34
Crompton wavelength
Electron magnetic moment
Electron-proton magnetic moment ratio
µe/µp
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Physico-Chemical Constants & Parameters
658.210 6881
0.010
Proton Constants
- table or chart of electron constants including symbol, value and units for values such as
proton mass, proton specific charge, proton molar mass, proton magnetic moment etc..
Proton constants are used in many areas of science and electronics for a variety of calculations.
The proton constants that come under the universal constants heading include items such as the proton mass, proton specific charge, proton molar mass,
proton magnetic moment etc..
Details for these electron constants and more are given below. The constant name, symbol, value, units and the relative uncertainty are provided.
CONSTANT NAME
SYMBOL OF
CONSTANT
Proton mass
mp
Proton mass in electron volts
Proton-electron mass ratio
mp/me
Proton specific charge
e/mp
VALUE
UNITS
RELATIVE
UNCERTAINTY
1.672 623 1
10^-27 kg
0.59
938.272 31
MeV
0.30
1836.152 701
0.020
9.578 830 9
10^7 C kg^-1
0.30
Proton molar mass
Mp
1.007 276 470
10^-3 kg/mol
0.012
Proton Crompton wavelength
λc,p
1.321 410 02
10^-15 m
0.089
µp
1.410 607 61
10^-26 J T^-1
0.34
Proton magnetic moment
Neutron Constants
- table or chart of neutron constants including symbol, value and units for values such as
neutron mass, neutron-electron mass ratio, neutron molar mass, etc..

CONSTANT NAME
Neutron mass
SYMBOL OF
CONSTANT
Mp
Neutron mass in electron volts
VALUE
UNITS
RELATIVE
UNCERTAINTY
1.674 928 6
10^-27 kg
0.59
939.565 63
MeV
0.30
Neutron-electron mass ratio
mn/me
1838.683 662
Neutron proton mass ratio
0.022
mn/mp
1.001 378 404
Neutron molar mass
Mn
1.008 664 904
0.009
Neutron Crompton wavelength
λcn
1.319 591
Neutron magnetic moment
µn
0.996 237 07
Neutron electron magnetic moment ratio
µn/µe
1.040 668 82
10^-3
0.24
Neutron proton magnetic moment ratio
µn/µp
0.684 979 34
10^-3 kg/mol
0.014
10^-15m
0.014
10^-26 J T^-1
0.41
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Physico-Chemical Constants & Parameters
0.24
- table or chart of physicochemical / physic-chemical constants, parameters & properties
including symbol, value and units for values including Avagadro constant, Faraday
constant, Boltzmann constant, standard atmosphere and many more..
Physical & fundamental constants pages include:
•
•
•
•
•
•
•
•
Fundamental physical constants
Universal constants
Electromagnetic constants
Atomic constants
Electron constants
Proton constants
Neutron constants
Physico-chemical constants
Physico-chemical constants parameters and properties are used in many areas of science and electronics for a variety of calculations.
The physicochemical parameters & properties that come under the universal constants heading include items such as the Avagadro constant, Faraday
constant, Boltzmann constant, standard atmosphere and many more.
Details for these physico-chemical parameters and more are given below. The constant name, symbol, value, units and the relative uncertainty are
provided.
CONSTANT NAME
Avagadro constant
Atomic mass constant
SYMBOL OF
CONSTANT
Na, L
6.022 136 7
Mu
1.660 540 2
Atomic mass constant in electron volts
Faraday constant
Molar Planck constant
VALUE
931 494 32
F
Nah
96.485 309
3.990 313 23
UNITS
10^23 mol^-1
RELATIVE
UNCERTAINTY
0.59
0.59
MeV
0.30
C mol^-1
0.30
10^-10 J s mol^-1
0.089
Molar gas constant
R
8.314 510
J mol^-1 K^-1
8.4
Boltzmann consant
k
1.380 658
10^-23 J K^-1
8.5
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