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Post by deland
' f& X+ i, L! n+ g) n: w 大家都没说错,认为电阻不变的说的很对,如果你还用国内带来的灯泡的话,亮度只是原先的四分之一,这就太暗了,所以你要换这里的灯泡,认为功率不变的说的也很对,要达到原先的效果,就得换相同功率的灯泡,但导线内的电流加倍,不过不用担心,如果灯具以前在220V下没有危险的话,在110V下接相同功率的灯泡也没有危险,电压降为一半,电流加倍,导线上发热的功率还是与原先一样的.
5 d2 D! y, W2 EYou are most right. But the last sentence is wrong. Here the power is
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I**2*R, not 110V*I.
. v7 R9 h# R& f. j- {3 ]+ @/ TIf you use the formula U*I, the U is the voltage difference between the two end points of the wire, it should be far less than 110V, otherwise the wire definately burns.! T; @$ S3 Q6 Y, s" i* q8 j
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2 H, O; y: B# F( q导线上发热的功率 is 4 times.
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5 |. a+ |3 g3 |( k* bTo be be simplest, buy a 40W local bulb (110V), and put it on. You will get 40W, and that is it. There is no problem for the wire except the wire is very very thin. |
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