Electromagnets are temporary magnets which have a magnetic field only when current passes through them. Some everyday applications of electromagnets include generators, motors, microphones, loudspeakers and cranes. Electromagnets are also used in scientific equipment such as particle accelerators, mass spectrometers and NMR (Nuclear Magnetic Resonance) spectrometers.Know More
Electromagnets are constructed by passing current through a coil of wire that may be wound around a central metal core. When current passes through the coil, it acts like a magnet and the magnetic field can be turned on or off with the current. The direction of the magnetic poles can also be reversed by reversing the direction of current.
Maglev trains work using electromagnets to hover the train above the tracks and change the polarity of the electromagnets in the tracks to help the train move forward. Particle accelerators also use electromagnets to accelerate charged particles by rapidly changing the polarity of the magnet.
Electric motors in appliances such as fans use electromagnets to do work. Current from the socket reaches the electromagnet, which moves and does work. Cranes in junkyards use electromagnets to lift scrap metal. When current flows through the magnet, the crane lifts the metal. After moving the metal to the desired location, the current is turned off to drop the metal. Magnetic Resonance Imaging (MRI) machines use electromagnets to capture images of the human body in a non invasive manner.Learn more about Magnetism
A magnet is an object or material that can produce a magnetic field of its own. That magnetic field is responsible for the property of magnets to attract or repel other magnets, and pull objects that are ferromagnetic, like iron. Electrons are the reason behind the production of magnetic fields and magnetism. In permanent magnets, spinning of electrons creates the magnetism.Full Answer >
A compass always points north because Earth's iron core creates a magnetic field that attracts the compass needle to the North Pole. However, a compass doesn't point directly to the North Pole; Earth's magnetic field is a little offset. This deviation from true north is called declination.Full Answer >
The magnetic field of a permanent magnetic material destabilizes on its own over a long period of time, generally on the order of hundreds of years. Magnets, however, weaken more quickly when they are exposed to physical shocks, other magnetic or electrical fields, and high temperatures.Full Answer >
Fleming’s right-hand rule is a commonly used mnemonic in both physics and electrical engineering that shows the direction of the current generated in a conductor that is forcefully made to cut perpendicularly through a magnetic field. The force vector is perpendicular to the current and magnetic field vectors.Full Answer >