Electromagnet vs Permanent Magnet
Electromagnet_
An electromagnet is a magnet that generates a magnetic field from an electric current. Electromagnets usually consist of wires wound into coils. Current passing through the wire creates a magnetic field concentrated in the hole, representing the center of the coil. When the current is turned off, the magnetic field disappears. The turns are usually wound around a magnetic core made of a ferromagnetic or ferrimagnetic material, such as iron; the core concentrates the magnetic flux, creating a stronger magnet.
permanent magnet_ _
Permanent magnets are objects made of materials that are magnetized and produce their own persistent magnetic field. An everyday example is a refrigerator magnet used to place notes on the refrigerator door. Materials that can be magnetized, that is, materials that are strongly attracted by magnets, are called ferromagnetic materials (or ferrimagnetic materials). These include the elements iron, nickel and cobalt and their alloys, some rare earth metal alloys, and some naturally occurring minerals such as magnetite.
