When transferring electricity over a long distance, the voltage is usually step up by a transformer to a high value to lower the current passes through the cables, so as to reduce power loss. However, why increasing the voltage can result lower current? And how can low current reduce power loss?
Please help answering my questions, thank you very much.
F.5 Physics E&M transformer question
2008-03-13 9:54 am
回答 (1)
2008-03-13 10:31 am
✔ 最佳答案
For a given amount of power, P=constant.By P=VI,
VI=constant.
V is inversely proportional to I.
Therefore,When V increase, I will decrease.
Power loss is due to ohmic losses in the conductors and is equal to the product of the resistance of the wire and the square of the current,i.e. P(loss)=I^2R
With a lower current, the power loss will be lower.
So, the high voltage reduce power loss.
參考: 我用中文讀CE= = 唔知你睇唔睇得明
收錄日期: 2021-04-13 15:16:38
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