How is an electromagnet different from a permanent magnet?

It has only south magnetic poles.
It has only north magnetic poles.
There is no magnetic field.
It can be turned on and off.

An electromagnet is different from a permanent magnet in that it can be turned on and off, whereas a permanent magnet always has a magnetic field. An electromagnet is created by passing an electric current through a coil of wire, which generates a magnetic field. The strength of the magnetic field can be controlled by adjusting the amount of current flowing through the coil. In contrast, a permanent magnet is made of a material that is naturally magnetic and always has a magnetic field, without the need for an external current.