Field and potential produced by point charges

Applet by Wolfgang Christian

Instructions on how to use the animation below:

  • Click on the buttons marked + or - to produced positive or negative charges, respectively (make sure that the check bow marked Charge is checked in order to view the charges)
  • Repeat the above step two or more times in order to produce multiple charges
  • All charges have equal magnitudes
  • You may move the charges by dragging them
  • Check the box marked Field Vec. in order to view the total electric field vectors produced by the charges
  • Check the box marked Contours in order to view equipotential lines
  • Check the box marked Labels in order to view the values of the potentials of the various equipotential lines
  • Click the box marked Test in order to produce a test charge
  • The vector on the test charge represents the total electrostatic force exerted on the test charge by the other charges at the location of the test charge. You may not be able to view the head of the vector if the test charge is too close to one or more of the other charges.
  • You can move the test charge by dragging it. Drag the test charge around in order too see how the electrostatic force exerted on the test varies at different locations.
  • Temporal controls:
    • After creating a test charge, click the button marked forward in order to see how the motion of the point charge would proceed assuming that the test charge was initially at rest at the location at which you situated the test charge
    • You may "pause or reverse" time by clicking on the buttons marked pause or reverse, respectively
    • Click on the buttons marked > in order step backward or forward in time, respectively, in temporal increments of 0.1