Electric Potential Difference

Claimed by Daniel Kurniawan

Electric Potential Difference, otherwise known as Voltage, is the difference in electric potential energy between two points per unit of electric charge. The voltage between two points is equal to the work done per unit of charge against a static electric field to move the test charge between two points and is measured in units of volts.

Voltage can be caused by static electric fields, by electric current through a magnetic field, by time-varying magnetic fields, or some combination of these three. One can use a voltmeter to measure the potential difference between two points in a circuit. A voltage may represent either a source of energy (electromotive force), or lost, used, or stored energy (potential drop).

Voltage

Definition

Say you have two points "a" and "b" in space. The potential difference is defined as the difference in electric potential between those two points. Electric potential is electric potential energy per unit charge, measured in joules per coulomb, otherwise known as volts.

\Delta V_{BA} = V(x_B) - V(x_A) = - \int_{r_0}^{x_B} \vec{E} \cdot d\vec{l} - \left( - \int_{r_0}^{x_A} \vec{E} \cdot d\vec{l} \right)

= \int_{x_B}^{r_0} \vec{E} \cdot d\vec{l} + \int_{r_0}^{x_A} \vec{E} \cdot d\vec{l} = \int_{x_B}^{x_A} \vec{E} \cdot d\vec{l}