The basic
principles of Diesel Electric Generators and electricity,We have
already mentioned electrical materials which are conductors (that
allow an electrical current to flow easily) and insulators (that
don't).
In reality nothing is a perfect insulator or a perfect conductor:
most materials have a certain degree of resistance, and lie
on a scale somewhere between a perfect insulator and a perfect conductor.
Materials with high resistance tend to be insulators; those with
low resistance tend to be conductors.
Even copper electrical cables
have a certain amount of resistance. Resistance is measured in ohms,
which is either abbreviated to ` ',
or to `R' if your word processor doesn't have a `'
symbol.
The
mathematical symbol is the letter `R' as well. One ohm is a lot
of resistance in electrical practice; we normally like our electrical
conductors to have resistances much less than an ohm, for
reasons that will be explained.
Electric Generator Store
|
