In physics, an electric field or E-field is an effect produced by an electric charge that exerts a force on charged objects in its vicinity. The units of the electric field are newtons per coulomb or volts per meter (both are equivalent). Electric fields are composed of photons and contain electrical energy with energy density proportional to the square of the field intensity. In the static case, an electric field is composed of virtual photons being exchanged by the charged particle(s) creating the field. In the dynamic case the electric field is accompanied by a magnetic field, by a flow of energy, and by real photons.

The electric field can be visualized by field lines, which point in the direction which a positive test charge would accelerate if placed upon the line. The lines are therefore directed away from positively-charged source charges and towards negative charges. An electric field line pattern can consist of any number of lines. However, the presence of a few lines around a charge is typically sufficient to convey the nature of the electric field in the space surrounding the charges.

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German version	[324 kB]
After downloading please unpack all files of the zipped packages and start the executable.

The program "EField" allows to place up to 4 unit charges at arbitrary positions. You may move the charges with the mouse, switch the polarity by double-clicking on a charge, and place test charges into the simulated electric field. For downloading the program click on the little floppy disk symbols at right.