ac electricity

[mcv1966]

any one know the main reason we use ac electricity in our homes instead of dc electricity?

[Its John!]

Perhaps because you can change the voltage of ac electricity. For example, they make the voltage something like 40,000 volts before its conducted to our homes, and then, before it enters our homes, its made to aout 230Volts. I dont think you can do this with dc

[kwicky]

Yes DC electricity cannot be changed from the generating source although you would experience voltage drop due to losses.
This explains it better than I can:

http://www.teachersdomain.org/resources/phy03/ sci/phys/mfw/acdc/index.html

[burdhead]

transformers only support ac current, allowing us to turn 400kv into the 230v which comes out of the mains

[oglecorp]

generators, by their nature, produce ac voltage. this voltage is stepped up in transformers, the result is high voltage and low current. overhead lines carry hundreds of thousands of volts but only a few amps. this reduces the power loss in the line as power is proportional to current squared. if you want to step up voltage in a transformer you need to use ac. plus ac motors and other devices are easier to make than dc ones.

[jake-the-peg]

This is a really facinating story.

There's a book out about it - effectively it was the first standards war between Edison (DC) and Tesla(AC)

There's a page about it here:
http://staff.fcps.net/rroyster/war.htm

and if you wnt more this is the book:

http://www.amazon.com/AC-DC-Savage-First-Stand ards/dp/0787982679