# Electrical field

**the electrical field** is a characteristic of the area, which assigns the direction-controlled size of the electrical field strength E **to each** space point. This is as follows defined: In the area at one point **r** = (x, y, z) a sample charge of the quantity *q* is platziert,so the field strength at this place is exactly** E** if on the sample charge Kraft **F** = **E**< math> \ /math< cdot>*q* works.

The unit of **E** in SI-UNITs is by Newton/ coulomb = N/C , this is therefore given equivalent to volts per meter, V/m.

The electrical field is a vector field, i.e. at each space point it is completely described by the size and the direction of the vector of the electrical field strength.

Electrical fields e.g. develop. by the presenceof electrical charges in the area or with the reproduction of light or other electromagnetic waves.

The electrical field in general form is both local and time-dependently, **E** = **E** (**r**, t). It is over the Maxwell equations and special relativity theory with the magnetic field links closely.
In special relativity theory its vector components are combined therefore inseparably with those of the magnetic field into a tensor. Depending on in which reference system one as observers is (i.e. inwhich relative movement to possibly existing space charges), over the Lorentztransformation the electrical field is transformed in such a way and turned around into a magnetic.

Due to the close relationship between electrical and magnetic field one combines both in electrodynamics into the electromagnetic field .

There are homogeneous and inhomogenous electrical fields. An electrical field means homogeneous, if the lines of flux run parallel, otherwise one is called it inhomogenously. Inside a plate capacitor the electrical field is always homogeneous.

In electrostatics the electrical field of resting becomeselectrical charges and charge distributions produces and does not change therefore not with the time. Then one speaks of an electrostatic field. In electrodynamics electrical charges and charge distributions also moved as well as temporally variable magnetic fields are regarded. In such a way produced electrical fieldsare thus also temporally variable.

*See also:* Field (physics), electrostatics, electrodynamics, line of flux