University of Wisconsin Green Bay

Three point charges are fixed in place as shown in the diagram.

What is the electric potential (due to these charges) at the origin?

  • In this problem, you are asked to find the electric potential due to a grouping of point charges. This is a definition problem—the electric potential is due the charges and you know an equation that relates them. Quantifying electric potential is merely restating the charge and location information that you already have in a slightly different way.

  • Although many definition problems do not require pictures, you will want one in this case to help you visualize the correct distance to each charge

  • In equation form, electric potential due to a point charge is defined as

    V = kq/r

    In this case, you will need to find the sum of the potentials due to three charges.

  • The electric potential at the origin due to the point charges shown is -2.4 X 105 J/C. No further numerical solution is required.