When current is flowing in a wire, what is actually moving is the electrons. Electrons have negative charges. Negative charge is usually shown in black, so in these illustrations electrons are represented as little black minus signs in little black circles. When they have the chance, electrons generally move from areas that are crowded with electrons (negative charge) to areas that don't have as many electrons (positive charge). The movement of electrons in a wire is illustrated here:
Notice that the arrow points from negative to positive, the direction that real electrons really move. You have probably seen current shown as going from positive to negative, which isn't how the electrons move.
Find out why current is usually shown from positive to negative.
This applet was written by Lisa Denise Murphy at the University of Illinois. Early drafts were written in 1999. The current version was last revised in January of 2000. Permission is given for students and teachers to use this applet, provided acknowledgement is made of the source. Anyone interested in using this applet in connection with any published paper or commercial venture should please first consult the author. Thank you.
This page last revised January 19, 2000.