11.3.4 Read the text, then match words and definitions

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.


Решение: 11.3.4Решение: 11.3.4