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
Unlike magnetic poles attract each other, and like magnetic poles repel each other. Magnets produce a magnetic field that is an area of magnetic force that determines whether the poles are attracted or repulsed.Full Answer >
Demagnetizing metal is done by displacing the dipoles that give it the magnetic qualities. This can be done by hitting the metal with a hammer once it's aligned correctly and heating it above its curie temperature.Full Answer >
Magnets do not stick to brass, as brass is not a ferrous metal. A ferrous metal contains small proportions of iron. Brass is an alloy of copper and zinc mixed in varying proportions. At no stage in its preparation is iron mixed in the alloy.Full Answer >
A magnetic field indicates the presence of an electric current, whether it is electricity running through a wire or electrons moving around atomic nuclei. The magnetic field generated by an electric current encircles it perpendicular to the direction of the current.Full Answer >