Understanding the Magnetic Field
These Magnetic fields are produced by the flow of electricity currents, unlike AC electric fields, Magnetic fields are only present when current is actually flowing. for example, a hairdryer that is plugged into a socket & turned ON will emit both AC electric & magnetic fields. When the hair dryer is switched off, current flow to the dryer stops and the magnetic field goes away. The electric field, which is caused by voltage rather then current flow will remain until the hair dryer is unplugged from the socket.