17/10/2014
The Directions Of Currents
we drew the current arrows in the direction in which positively charged particles would be forced to move through the loop by the electric field. Such positive charge carriers, as they are often called, would move av.cy from the positive battery terminal and toward the negative terminal. Actually, the charge carriers in the copper loop of lb are electrons and thus are negatively charged. The electric field forces them to move in the direction opposite the current arrows, from the negative terminal to the positive terminal. For historical reasons, however, we use the following
convention:
A current arrow is drawn in the direction’in .whichpositive charge carriers would move, even if the actual charge carriers are negative anime in the opposite directionWe can use this convention because in most situations, the assumed motion of positive charge carriers in one direction has the same effect as the actual motion of negative charge carriers in the opposite direction. (When the effect is not the same, we shall, of course, drop the convention and describe the actual motion.
