Electric and magnetic fi elds can occur separately or together, and accordingly it
is possible for humans to be exposed to just one of these fi elds or both of them. For
example, when a power cord is plugged into a socket outlet it creates an electric fi eld
along the cord. When the lamp is turned on, the fl ow of current through the cord creates a magnetic fi eld; and the greater the current, the stronger the magnetic fi eld. In
the meantime, the electric fi eld is still present.