Define the meaning of the words in bold. 2 defenitions are extra.

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The practical applications of superconductivity are limited because of the very low temperatures required. Some materials, for example lead, become almost perfect conductors at very low temperatures at the absolute zero (—273 °C). However, a number of uses have been proposed.

If a current is induced by a magnetic field in a ring of superconducting material, it will continue to circulate when the magnetic field is removed. In theory this could be made use of in the memory cells of computers. Memory cells made of superconducting material could store information indefinitely. Because of the zero resistivity of the cells, the information could be retrieved quickly, as fast as 10⁻⁸ seconds.

90 per cent of the total losses in modern transformers is due to the resistance of the windings. Transformers could be made with windings cooled to the low temperature at which superconductivity occurs. The resistance would be zero and the transformer would be almost ideal. Similarly, a 100 % efficient electric motor has been proposed using the magnetic field of superconducting coils.

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cell

a piece of equipment for producing electricity from chemicals, heat, or light

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lead

a soft heavy grey metal that melts easily and is poisonous, used on roofs, or in the past for water pipes.

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coil

a wire or a metal tube inacontinuous circular shape that produces light or heat when electricity is passed through it

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windings

material (as wire) wound or coiled about an object (as an armature); also: a single turn of the wound material

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retrieve

to find something and bring it back

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current

a flow of electricity through a wire

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