Voltage
Related wiki pages: Electronic Theory, Capacitors. Resistors. Inductors, transformers
What is Voltage?
In practical terms, voltage id the difference in electrical potential between two points in a circuit. The unit of measurement is the volt (V), which is a measure of the energy per unit charge.
Voltage is one of the properties of an electric field, and can be measured in terms of:
- its relationship to a common point. This is usually with respect to ground (zero volts)
- the relationship between two points. This is usually known as the voltage across a device or the voltage across a circuit.
In physical terms, Voltage is the work required to move an electric charge between two points:
1 Volt is the force required to send one Ampere of current through a resistane of one Ohm.
Some Formulae
- <math> V = \sqrt{PR} </math>
- <math> V = I \times R </math>
- <math> P = V \times R </math>
where V = potential difference (volts), I = current intensity (amps), R = resistance (ohms), P = power (watts).
Voltage across Resistors, Capacitors and Inductors
Voltage cross a resistor (Resistor R):
- <math> V_R = IR_R \!\ </math>
Voltage across a capacitor (Capacitor C):
- <math> V_C = IX_C \!\ </math>
Voltage across an inductor (Inductor L):
- <math> V_L = IX_L \!\ </math>
Where V=voltage, I=current, R=resistance, X=reactance.