# Tag Info

You want something like the Poisson-Boltzmann equation, or its linearized form, the Debye-Huckel equation. To illustrate the effect, consider an immobile spherical charge $Q$ at the center of your coordinate system, surrounded by small mobile charge carriers of charge $\pm q$. Gauss's law will give you the potential $\phi(r)$ as a (spherically symmetric) ...