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Sir. First of all thanks for answering us. My question is that why should AC current change its direction that many times a minute, doesn't it travel without changing direction? How does it change its direction? Is it due to increase and decrease in potential or is it due to some other reason?
- Prudhvi Raj Borra (age 16)
Yes, the ac in the US changes direction 7200 times a minute. In most of Europe, it's 6000 times a minute. In most cases the original generator of the electrical power has an ac output.
Here's a simple example of how that would work. Take a bar magnet near an electrical coil. Spin the bar magnet (maybe using a windmill or steam engine or water wheel). The field in the coil will keep changing, alternating sign. As it does, the current driven in the coil by the changing field will alternate sign.
(published on 07/03/09)
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