Consider a group of charges q_1, q_2, q_3 … such that Σ q ≠ 0. Then equipotentials at a large distance, due to this group are approximately:

Consider a group of charges $\displaystyle \mathrm{q}_{1}, \mathrm{q}_{2}, \mathrm{q}_{3} \ldots$ such that $\displaystyle \Sigma \mathrm{q} \neq 0$. Then equipotentials at a large distance, due to this group are approximately :