Fundamental and Derived Units
Some Physical Fundamental and Derived Units.
Fundamental (Primary) Units
Quantity |
Name of Unit |
Definition |
length |
meter (m) |
|
mass |
kilogram (kg) |
|
time |
second (s) |
|
electric current |
ampere (A) |
Coulomb/second |
thermodynamic temperature |
kelvin (K) |
|
amount of substance |
mole (mol) |
|
luminous intensity |
candela (cd) |
|
Derived Units
Quantity |
Name of Unit |
Definition |
capacitance |
farad (F) |
Coulomb/volt, (amp * second/volt) |
charge, quantity of |
Coulomb (C) |
(amp * second) |
energy (work) |
Joule (J) |
Newton-meter, (kg * m2 / sec2) |
force |
Newton (N) |
Joules/meter, kg * m / sec2 |
inductance |
Henry (H) |
volt * second/Ampere |
magnetic flux |
Weber (Wb) |
volt * second, (Mead page11) |
magnetic flux density |
Tesla (T) |
(Webers / meter2); (joules * second) / (Coulomb * meter2); (Note: 1 tesla = 1.0e4 Gauss = 1Newton/(amp * meter)) |
potential difference (electromotive force) |
volt (V) |
joules/Coulomb, (kg * m2 / (sec2 * Coulomb)), watts/Ampere |
power |
Watt (W) |
joules/second, (volts * Ampere) |
resistance |
Ohm |
volts/Ampere |
Fundamental Constants
Constant |
Symbol |
Value |
speed of light |
C |
2.99792458e8 m/s, Halliday-Resnick appendix B |
charge, elementary |
e |
1.60217738e-19 C, Halliday-Resnick appendix B |
electric permittivity constant (in vacuum) |
epsilon0 |
8.85418781762E-12 F/m, Halliday-Resnick appendix B |
Planck’s constant |
h |
6.6260754e-34 j-s, Halliday-Resnick appendix B |
Planck’s constant / (2.0 * pi) |
hbar |
1.055e-34 joules-sec |
Complex number |
i |
sqrt(-1) |
magnetic permeability constant (in vacuum) |
mu0 |
4.0 * pi * 1.0e-7 H/m (Newton/amp2), GriffithsED page216 |
 |
Eqn:D.1 |
See Also
References
- GriffithsED – Introduction to ElectroDynamics, (3rd edition) 1999
- Halliday – Halliday, Resnick, Fundamentals of Physics, 1993