Electric field lines from point charges

What you are seeing: field lines of $\mathbf{E}$ for four canonical configurations. Each line is an integral curve of the electric field; by Gauss's law, the line density on the plane is proportional to $|\mathbf{E}|$. Field lines start from positive charges and either terminate on a negative charge or escape to infinity.

The dipole shows the classic figure-eight pattern with lines bridging from + to -. Two like charges produce a "no crossing" pattern with a zero-field point at the midpoint. The quadrupole produces four lobes with field cancellations between alternating signs. The monopole shows radial lines that decay slower than the higher-order configurations. Drag any charge with the mouse to reposition it; field lines re-trace live. Press shoot test charge to send a + test charge through the field.