We can represent electric potentials pictorially, just as we drew pictures to illustrate electric fields. This is not surprising, since the two concepts are related. We use arrows to represent the mag...We can represent electric potentials pictorially, just as we drew pictures to illustrate electric fields. This is not surprising, since the two concepts are related. We use arrows to represent the magnitude and direction of the electric field, and we use green lines to represent places where the electric potential is constant. These are called equipotential surfaces in three dimensions, or equipotential lines in two dimensions.