Study electrical fields with this tool. Electric Field Lines enable you 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.
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 license of this software is Freeware, you can free download and free use this calculator software.