Question

unit 7 \physical interaction\ test
an electromagnet is
○ a permanent magnet.
○ attracts all metal substances.
○ only operating when the current is on
○ made with bar magnets.

Explanation:

An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. When the current is off, it loses its magnetism. It doesn't attract all metal substances (only ferromagnetic ones), isn't a permanent magnet, and isn't made with bar - magnets in the sense described here.

Answer:

C. only operating when the current is on