Resistance
Abbr.r,R【Electricity】 The opposition of a body or substance to current passing through it,resulting in a change of electrical energy into heat or another form of energy.
缩写 r,R【电学】 电阻：阻挡电流通过的物体或物质,从而把电能转化为热能或其它形式的能量.
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Intensity of current
Abbr.i I,电流强度
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U 电压
American writers usually use the letter V for the quantity volts.In order to distinguish the quantity symbol from the unit symbol,we have here used U for the quantity voltage.U is the ANSI reserve symbol.
美国人通常使用字母V表示电压.为了与单位电压有区别,我们用U表示电压,U是美国国家标准学会的候补符号.而用V表示单位电压,即voltage .