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 | eo |
8.854 187 817 ... x 10-12 | F m-1 |
| Free space Permiability | mo |
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 | m3 kg-1 s-2 |
| Electron rest mass | me |
9.109 3826 x 10-31 | kg |
| Proton rest mass | mp |
1.672 621 71 x 10-27 | kg |
| Neutron rest mass | mn |
1.674 927 28 x 10-27 | kg |
| Accelertion due to Gravity | g |
9.806 65 | kg m s-2 |
| Avogadro number |
NA |
6.0221367 x1023 | 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) | Po |
101 325 | Pa |
| Standard Atmospheric Temperature (sea level) | To |
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