An electromagnet is a device in which moving electric charges (current) in a coil of wire create a magnet. What’s one advantage
of using electromagnets in devices? A.
Electromagnets have a strong, constant magnetic field.
B.
Electromagnets are more powerful than permanent magnets.
C.
Electromagnets don’t need a source of electricity to work.
D.
Electromagnets can easily be turned on and off.
An electromagnet produces magnetic field which is done by the electric current. These electromagnets contain a wire would like a coil. The current passes through the wire and the magnetic field is concentrated in the center which is the "center of the coil".
When the current is "turned off" the magnetic field "disappears". This shows that we have can have a control over the passage of current or the magnetic field. Thus, the "main advantage" of the electromagnet is that it can be easily turned on and off whenever necessary.
