对RL串联路作如下两次测量: 1.端口加90V直流电压(ω=10)时,输入电流为3A 2.端口加f=50Hz的正弦电压90V时,电流为1.8A。求R和L的值
正确答案:
由题意画电路图,如下图所示。
![](https://img.274949.com/Images/2020-04/10/i9av7qbm.jpg)
可见当U为90V直流电压时,电感相当于短路,则电阻:![](https://img.274949.com/Images/2020-04/10/vseb816q.jpg)
当Us为90V交流电压时,这电流I=
根据相量法,有:
![](https://img.274949.com/Images/2020-04/10/i9av7qbm.jpg)
可见当U为90V直流电压时,电感相当于短路,则电阻:
![](https://img.274949.com/Images/2020-04/10/vseb816q.jpg)
当Us为90V交流电压时,这电流I=
![](https://img.274949.com/Images/2020-04/10/5bi24ydv.jpg)
![](https://img.274949.com/Images/2020-04/10/gveyqkeg.jpg)
答案解析:有
![](/editor/images/201705/qrcode_for_gh_573e2a458573_258.jpg)
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对RL串联路作如下两次测量: 1.端口加90V直流电压(ω=10)时,输入电流为3A 2.端口加f=50Hz的正弦电压90V时,电流为1.8A。求R和L的值
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