SOME ELECTRICAL UNITS
| Practical Units. | Electrical Quantity |
|---|
| | Volt | is the practical unit of EMF |
| | Ampere | is the practical unit of I |
| | Ohm | is the practical unit of R |
| Watt | is the practical unit of P |
OHM’S LAW
Since the intensity of an electric current varies directly as the electromotive force and inversely as the resistance, if you know the value of any two of the above units you can easily find the third.
| Amperes | = | Volts | , or | I | = | E |
| Ohms | R |
| Electromotive Force | = | Current | , or | E | = | I |
| Resistance | R |
| Resistance | = | Electromotive Force | , or | R | = | E |
| Current | I |
To Find Power of an Electric Current in Terms of Horse Power
| One Watt | = | 1 volt × 1 ampere |
| 746 Watts | = | 1 horse power. |