This page contains some of the constants commonly used in radiocommunications work. I can't always remember them so having them on a web page is useful to me and hopefully to others too.
p = 3.141 592 653 59
e = 2.718 281 828 46
Constant | Symbol |
Value | Units |
Electron charge | q |
1.602 176 53 x 10^{-19} | Coulomb |
Free space Permitivity | e_{o} |
8.854 187 817 ... x 10^{-12} | F m^{-1} |
Free space Permiability | m_{o} |
4p x 10^{-7} = 12.566 371 x 10^{-7} | N A^{-2} |
Planck constant | h |
6.626 0693 x 10^{-34} | J s |
Speed of light | c |
299 792 458 | m s^{-1} |
Boltzmann constant | k |
1.380 6505 x 10^{-23} | J K^{-1} |
Characteristic impedance of vacuum | Zo |
376.730 313 | Ohms |
Newtonian constant of Gravitation | G |
6.6742 x 10^{-11} | m^{3 }kg^{-1} s^{-2} |
Electron rest mass | m_{e} |
9.109 3826 x 10^{-31} | kg |
Proton rest mass | m_{p} |
1.672 621 71 x 10^{-27} | kg |
Neutron rest mass | m_{n} |
1.674 927 28 x 10^{-27} | kg |
Accelertion due to Gravity | g |
9.806 65 | kg m s^{-2} |
Avogadro number |
N_{A} |
6.0221367 x10^{23} | particles/mol |
Stefan-Boltzmann constant | s |
5.670 400 x 10^{-8} | W m^{-2} K^{-4} |
Constant | Symbol |
Value | Units |
Earth Radius | R |
6378.137 | km |
Standard Atmospheric Pressure (sea level) | P_{o} |
101 325 | Pa |
Standard Atmospheric Temperature (sea level) | T_{o} |
288.15 | K |
Water Freezing point (sea level, standard pressure) | 273.15 | K | |
Temperature lapse rate (lower 11km of troposphere) | -6.5 | K km^{-1} |
© Mike Willis
26th March 2005