An eddy current is an electrical current induced in a piece of metal due to the relative motion of a nearby magnet. Any time a magnet passes a metallic object, its magnetic field induces an electric current, which swirls around near the surface of the metal like an eddy in a river. This electric current creates its own magnetic field, which opposes the motion of the magnet.Know More
Eddy currents are responsible for some remarkable effects when properly utilized. The opposing magnetic fields produced by eddy currents can result in marked slowing of the motion of a magnet, even when it is otherwise in free fall. A strong magnet dropped through a thick copper tube, for instance, falls far more slowly than it would under the influence of gravity alone.
This effect is only observed when magnets move near metals, not nonmetals. This is because of the nature of the metallic bonds in solid metals, which allow for the relatively free flow of electrons between atoms. This is the same property that is responsible for the generally good electrical conductivity of metals. Because of this property, it is relatively easy for magnetic fields to start an electric current, which is just another way of saying electron movement.Learn more about Electricity
The easiest way to tell if something is real gold or gold plate is by holding a magnet up to the piece and waiting for the metal inside the piece to attract to it. If the piece is gold-plated, it is instantly connected to the magnet. If the piece is solid gold, it does not connect.Full Answer >
M & M Gold Exchange notes that jewelers and others have long used the same tests, including applying nitric acid and attempting to attach a magnet to a metal piece, to verify an item is made of real gold. In the United States, anything less than 10 karats is not considered real gold.Full Answer >
A transformer changes the voltage of an electric current while transferring it from one circuit to another through electromagnetic induction. Fluctuating magnetic fields in the transformer generate an electric current in a coil of wire, and the voltage they put out is directly proportional to the number of turns in the coil of wire.Full Answer >
Electrostatic discharge, or ESD, is a sudden flow of electric current between two objects that have different electronic potentials. An electric spark is a type of ESD wherein there is a flow of electric current across an air gap, increasing the air temperature, which produces light and sound emission.Full Answer >