When voltage and current developed in an AC circuit reach their peak values at the same time, the power factor is _____.

A．lagging

B．leading

C．maximum

D．minimum

Nothing happened____they got the photo developed, When they looked at the photo,

3 when it comes to the environment problem ,developed countries should invest mo

[名词解释] 标称电压（nominal voltage）

[名词解释] 故障电压（fault voltage）

[名词解释] 英译汉：voltage

[单选题]（）的英语是voltage。A . 电压B . 电阻C . 电流D . 电器

[名词解释] 额定电压（rated voltage）

The voltage is CEMF (Counter Electromotive Force).A. 对B. 错

[单选题]The output voltage of a 440 volt, 60 hertz, AC generator is controlled by theA．prime mover speedB．exciter output voltageC．load on the alternatorD．number of poles

[名词解释] 接触电压限值（touch voltage limit）