The current density in a resistor can be related to the drift velocity of the electrons and the “density of free electrons” in the material, n: \[→j=−en→vd\...The current density in a resistor can be related to the drift velocity of the electrons and the “density of free electrons” in the material, n: →j=−en→vd where, e, is the magnitude of the charge of the electrons and the minus sign indicates that the current density is in the opposite direction of the velocity of the (negative) electrons.
