Today we"re going to describe and explain the hall effect. Calculate the magnetic field due to a current in a straight wire. The hall effect is an effect of a magnetic field creating an electric field. Recall that the magnetic force on a current depends on the direction of the current, not on the sign of the charges. Imagine this set up or a wire with the dots representing charge carriers moving through it. In this set up the charge carriers would all be forced up by the magnetic force and concentrate on the upper edge of the wire (think due to the rhr). If the charge carriers were electrons, this would create a high concentration of negative electric charge on one section of the wire. This large concentration of charge produces an electric field! There is also thus a corresponding potential that would be associated with this field pointing towards the concentration in this case.
