Wednesday, January 30, 2008

What is Voltage?

There are a lot of terms associated with electricity. Different words refer to a current’s strength, the speed at which it travels, and the rate at which it’s consumed. Voltage is a sometimes-misunderstood term that means “electomotive force” or, more simply, electrical “pressure.” Voltage also is the difference in electrical potential between one end of a circuit and the other. In our electrical systems, voltage is measured against the earth, which is at zero potential. In other words, it all starts with the ground under your feet. Voltage gets the electrical ball rolling by giving a push to electric power from your utility’s generator to your house or business.
Long-distance power lines carry huge voltages, from around 155,000 to 765,000 volts. If you hooked your vacuum cleaner up to that kind of power, you’d melt its engine instantly—and possibly yourself as well. You previously read that transformers reduce the voltage before it enters your house. A few hundred thousand volts might sound like fun to your kids, but you should be grateful that you end up with a lot less voltage, thanks to transformers.

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