Instructions: Select the correct answer.

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.