02-05E

Analytic solution of the Poisson's equation for a system of two like charges near a uniformly charged plane is used to explain the phenomenon of an attraction between a pair of colloids bound by a charged glass wall that has been observed recently. We found that there is no attractive interaction between like charges. We have shown that what is observed experimentally could be interpreted as the "apparent attraction" resulting from the extra force experienced by each charge being in the electric field due to the charged surface. This surface-induced force is directed to the center of the surface and under appropriate conditions works against the Coulomb repulsion between like charges. Both the field and force can be revealed naturally within the framework of classical electrodynamics if the effects of the finite size of a charged surface are taken into account.