如图,发电机的电动势e=678sin 100πt V,变压器的副线圈匝数可调,触头P置于a处时,用户的用电器恰好得到220 V的电压,R表示输电线的电阻.下列说法正确的是( )
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/29/747400db-e7f1-45c9-b203-32de0bc52b38.png?resizew=361)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/29/747400db-e7f1-45c9-b203-32de0bc52b38.png?resizew=361)
A.电流的频率为50 Hz |
B.电压表V2的示数为220 V |
C.电压表V1的示数为678 V |
D.当用户的用电器功率增加时,要保持用户仍得到220 V的电压,触头P应向上滑 |
更新时间:2018-06-23 22:58:14
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【推荐1】如图所示的电路中,可调变压器为理想变压器,R为滑动变阻器,在c、d两端输入有效值恒定的正弦交流电压,调节
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【推荐2】如图所示,一理想变压器原、副线圈匝数比为
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