Potentialsskillnaden

Potentialsskillnaden is the Swedish term for the potential difference, the difference in electric potential between two points. It represents the energy per unit charge that would be transferred when moving a test charge between those points and is a fundamental concept in electricity and magnetism. The term can also be used more generally for differences in potential energy per unit charge in conservative fields.

In physics, the potential difference ΔV between two points A and B is defined as ΔV = V(B) − V(A). In an electrostatic field, this equals the negative line integral of the electric field: ΔV = −∫ from A to B of E · dl. The work done on a charge q moving from A to B is ΔU = q ΔV. Because the electric field is conservative, the result depends only on the endpoints, not on the path taken.

In electrical circuits, potential difference is the voltage between two terminals and is measured with a voltmeter. It is the quantity that can drive current through a circuit element. An ideal voltage source maintains a fixed ΔV regardless of current, while real sources have internal resistance that affects the actual voltage under load.

Units and generalization: the SI unit of potential difference is the volt (V). The concept extends beyond electricity to other conservative fields, such as gravity, where the gravitational potential difference ΔΦ equals the work done per unit mass to move between points.

Applications include powering devices, analyzing circuit behavior with Ohm’s law (V = I R), and determining energy transfer and efficiency in electrical systems. See also electric potential, voltage, ohm’s law, voltmeter.