WordNet
n. (computer science) a doughnut-shaped magnet formerly used to store one bit of information in the main memory of a computer; now superseded by semiconductor memories
Wikipedia
A magnetic core is a piece of magnetic material with a high magnetic permeability used to confine and guide magnetic fields in electrical, electromechanical and magnetic devices such as electromagnets, transformers, electric motors, generators, inductors, magnetic recording heads, and magnetic assemblies. It is made of ferromagnetic metal such as iron, or ferrimagnetic compounds such as ferrites. The high permeability, relative to the surrounding air, causes the magnetic field lines to be concentrated in the core material. The magnetic field is often created by a coil of wire around the core that carries a current. The presence of the core can increase the magnetic field of a coil by a factor of several thousand over what it would be without the core.
The use of a magnetic core can enormously concentrate the strength and increase the effect of magnetic fields produced by electric currents and permanent magnets. The properties of a device will depend crucially on the following factors:
- the geometry of the magnetic core.
- the amount of air gap in the magnetic circuit.
- the properties of the core material (especially permeability and hysteresis).
- the operating temperature of the core.
- whether the core is laminated to reduce eddy currents.
In many applications it is undesirable for the core to retain magnetization when the applied field is removed. This property, called hysteresis can cause energy losses in applications such as transformers. Therefore, 'soft' magnetic materials with low hysteresis, such as silicon steel, rather than the 'hard' magnetic materials used for permanent magnets, are usually used in cores.
Usage examples of "magnetic core".
He therefore moved around from the ship's belly, almost creasing the side of the ship, trying to head first for the bridge, then for the main engine's magnetic core.
He compounded the electricity found in seawater before running it through a highly magnetic core tube kept at absolute zero by liquid helium.
And perhaps it is this hard, magnetic core inside you which attracts others to you willy-nilly.
Like some superdense piece of lead being drawn toward the earth's magnetic core, pulling him down with it.
Pittsburgh is on Elfhome because the gate projects the veil effect down through the Earth, where the magnetic core bends it, kind of like a prism bends light, thus hitting Pittsburgh on the other side of the planet.
He didn't think about Bonnie or flying or anything else except matching the myriad possible permutations of the human genetic code and storing the knowledge in Ramo's magnetic core memory.
And there were wrecks on wheels and wrecks on treads, some with claws and some with cannon, all sundered to the magnetic core, and tank-turtles with squashed turrets, and mutilated military millipedes, and other oddities, broken and battle-scarred, some equipped with auxiliary brains (burnt out), some perched on telescoping stilts (dislocated), and there were little vicious biting things strewn about.
The magnetic core of the planet was too strong, the human resistance too determined.