Force Vectors

Like charges   Unlike charges


Two fixed charges are shown in black. Select either "Like Charges" or "Unlike Charges" to have the field lines drawn.

You may click and drag the small green test charge to different positions in the electric field around the two charges.  We are interested in observing the relationship between the dark blue force vector on the test charge and the light blue field lines.


  1. Move the test charge around in the electric field. Describe the relationship between the force vector on the test charge and the field lines.
  2. When you hit the "play" button, does the test charge follow the field lines? Does it do this for all field lines, or just some field lines? Explain.
  3. What happens to the test charge when it is placed on a horizontal line joining the two charges? Try several places on this line for both the "Like Charges" and "Unlike Charges" configurations.

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