Conductors

Conductors are materials having a low resistance, so that current easily passes through them. The lower the resistance of the material, the more current can pass through it.

The most common conductors are metals, and silverandcopper are the best of them. The advantage of copper is that it is much cheaper than silver. Thus, copper is widely used to produce wire conductors. One of the common functions of wire conductors is connecting voltage source to a load¹ resistance. Since copper wire conductors have a very low resistance a minimum voltage drop² is produced in them. Thus, all of the applied voltage can produce current in the load resistance.

Most materials change the value of resistance when their temperature changes.

Metals increase their resistance when the temperature increases while carbon decreases its resistance when the temperature increases. Thus, metals have a positive temperature coefficient of resistance while carbon has a negative temperature coefficient. The smaller is the temperature coefficient or the less the change of resistance with the change of temperature, the more perfect is the resistance material.

Пояснения к тексту

1. load—нагрузка

2. a drop — падение

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