Question

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?
Electromagnets have a strong, constant magnetic field.

Electromagnets are more powerful than permanent magnets.

Electromagnets don’t need a source of electricity to work.

Electromagnets can easily be turned on and off.

Answer 1

Electromagnets have certain advantages over permanent magnets. One of the major advantage is, the amount of electric current can easily be controlled, in turn, magnetic field can be controlled. Out of all the options, option D would be the best answer.

In short, Your Answer would be option D) Electromagnets can easily be turned on and off.

Hope this helps!