electric field

An electric field is a vector field that describes the force per unit charge exerted on a test charge due to the presence of other electric charges. An electric field can be generated by:

1. the presence of an electric charge (Gauss’ law)

2. a changing magnetic field (Faraday’s law)

3. moving charges or electromagnetic waves (Ampère-Maxwell’s law)

   

Mathematically, the electric field at a point is defined as:

$$\mathbf{E}=\frac{\mathbf{F}}{q}$$

where
$\mathbf{E}(\mathbf{x},t)$	electric field, measured in volts per meter $\frac{\text{V}}{\text{m}}$
$\mathbf{x}$	position vector in three-dimensional space, typically expressed as $\mathbf{x}=(x,y,z)$ and measured in meters $\text{m}$
$t$	time, measured in seconds $\text{s}$
$q$	electric test charge, measured in coulomb $\text{C}$
$\mathbf{F}(\mathbf{x},t)$	force vector experienced by the test charge, measured in newtons $\text{N}$