题目内容
某发电厂原来用电压为U1的交流电输电,后改用变压比为1∶50的升压器将电压升高后输电,输送的电功率保持不变.若输电线路的电阻为R,则下列说法中正确的是
A.由公式![]() ![]() |
B.由公式![]() |
C.由公式![]() ![]() |
D.由公式![]() |
AC
试题分析:根据公式
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824212706199680.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824212659194506.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824212700364386.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824212701519509.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824212700364386.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824212702813476.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824212703937491.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824212705013606.png)
故选AC
点评:关键是对公式中的各个字母表示的含义正确理解
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目