particle in this field is parallel to the field line (and in the direction of the arrows) at the position of the particle. Since a force exists, then work is done if the particle moves along the line, and the particle moves toward lower electric potential. The dashed lines are electric equipotential lines. The particle gains energy as it passes ... The electric field lines can be plotted using streamline(x, y, Ex, Ey, sx, sy) where Ex and Ey are the vector components of the electric field defined at points (x, y) and sx and sy are the points ... The electric field is another important concept in electrostatics. It is easy to map the electric field lines using the equipotential lines. Unlike the electric potential, the electric field E is a vector quantity; it has magnitude and direction. The electric field is given by the change of electric potential over a change in position.