| frequence | | |
| period | | |
| frequency - the number of periods per second | | |
| period - the shortest time in which the time behaviour of a deviation repeats | | |
| harmonic voltage | | |
| voltage amplitude | | |
| root-mean-square voltage | | |
| Effective voltage of a supply of alternating current equals a voltage of a supply of direct current with identical heat effects. | | |