如图所示,球形电极浮在相对电容率为εr=3.0的油槽中.球的一半浸没在油中,另一半在空气中.已知电极所带净电荷Q0=2.0×10-6C.问球的上、下部分各有多少电荷?
正确答案:
将导体球看作两个分别悬浮在油和空气中的半球形孤立电容器,上半球在空气中,电容为
![](https://img.274949.com/Images/2020-04/04/0xgx4haq.jpg)
下半球在油中,电容为
![](https://img.274949.com/Images/2020-04/04/msip0wep.jpg)
由分析中式(1)和式(2)可解得
![](https://img.274949.com/Images/2020-04/04/0f053lyk.jpg)
![](https://img.274949.com/Images/2020-04/04/drsvdsg3.jpg)
![](https://img.274949.com/Images/2020-04/04/0xgx4haq.jpg)
下半球在油中,电容为
![](https://img.274949.com/Images/2020-04/04/msip0wep.jpg)
由分析中式(1)和式(2)可解得
![](https://img.274949.com/Images/2020-04/04/0f053lyk.jpg)
![](https://img.274949.com/Images/2020-04/04/drsvdsg3.jpg)
答案解析:有
![](/editor/images/201705/qrcode_for_gh_573e2a458573_258.jpg)
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如图所示,球形电极浮在相对电容率为εr=3.0的油槽中.球的一半浸没在油中,另一半在空气中.已知电极所带净电荷Q0=2.0×10-6C.问球的上、下部分各有多少电荷?
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