點解用高壓(high voltage)輸電電流(current)會鈿左？
回答 (2)
2008-04-20 11:02 pm
✔ 最佳答案
Ohm's law only apply for a closed circuit. when the voltage ishigh , the current will also be high.(resistance is constant)
but in the transmission of electricity, assume no energy loss,
power input is equal to power output.
VI=V'I'
so we V is large, I will be small.
and when V is small , I will be large.
2008-04-20 10:37 pm
係P=VI
Power 係constant 既話
V大左
I就會細左
Power 係constant 既話
V大左
I就會細左
收錄日期: 2021-04-29 20:26:17
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080420000051KK01439