When a positively charged conductor (A) is joined by a metal wire to an uncharged conductor (B), electrons will indeed move from the uncharged conductor (B) to the positively charged conductor (A).

This movement of electrons occurs due to the potential difference between the two conductors. In the beginning, conductor A has an excess of positive charge, creating a positive potential. Conductor B is initially neutral, so it has no net charge and a potential of zero.

When the two conductors are connected by a metal wire, electrons, which are negatively charged, will move from the region of lower potential (conductor B) to the region of higher potential (conductor A). This movement of electrons will continue until the potentials of both conductors equalize, and the system reaches electrostatic equilibrium.

As a result, conductor A will gain electrons, becoming less positively charged, while conductor B will lose electrons, becoming positively charged. The overall effect is that charge redistributes until the potentials are equalized, and both conductors have the same net charge.