A magnet is made of any of a group of metals called ferromagnetic metals. Ferromagnetic metals contain many small magnetic fields called domains. In their natural state, the magnetic fields of these domains point in different directions. To create a magnet, the magnetic fields must align in the same direction.
Magnets are either temporary or permanent. The easiest type of magnet to make is a temporary magnet. Simply subjecting a ferromagnetic material to the magnetic field of an existing magnet causes its domains to align temporarily, producing a magnetic field that lasts for a short time after the original magnet is removed. Creating a permanent magnet involves heating ferromagnetic metal to a specific temperature, called the Curie temperature, causing the magnetic fields of individual domains to point in the same direction. Heating past the Curie temperature causes the material to become a permanent magnet.
An electromagnet uses electricity to temporarily magnetize a ferromagnetic metal, typically iron. Wrapping copper wire around an iron nail and connecting the wire to a battery creates a flow of electricity that aligns the magnetic domains.
A superconducting magnet, of use in MRI machines, utilizes metal alloys that conduct electricity well at extremely low temperatures. Cooling a loop of niobium and adding an electrical charge creates a very stable magnetic field.Learn More
Factors that can make a electromagnet stronger are increasing a coil's current flow, adding an iron core and increasing the number of turns to a coil. Building an electromagnet involves wrapping a copper wire around an iron core like a nail. A battery is then attached to this setup so that a current can flow through it.Full Answer >
An AC generator, also called an alternator, is a device that converts mechanical energy into electrical energy. "AC" stands for "alternating current." The device generates alternating voltage by rotating a coil in the magnetic field.Full Answer >
Tin is magnetic in the literal sense of the word. The effect is so weak that it could be considered non-magnetic for all practical purposes. It is called a paramagnetic substance scientifically, but it has such a weak effect that it can be compared to a diamagnetic element.Full Answer >
Magnetic levitation is a method of supporting an object with the repulsive force of magnets and the stability of servomechanisms. The object is thus suspended in the air, counteracting the effects of gravity.Full Answer >