题目内容
真空中有A、B两个点电荷,相距r时相互作用力为F,欲使它们之间的相互作用力变为
,下列方法可行的是
A、将它们的电量均变为原来的2倍
B、将它们的电量均变为原来的一半
C、将它们之间的距离变为
r
D、将它们之间的距离变为![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824145009340391.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824145009231420.png)
A、将它们的电量均变为原来的2倍
B、将它们的电量均变为原来的一半
C、将它们之间的距离变为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824145009278260.png)
D、将它们之间的距离变为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824145009340391.png)
C
试题分析:设变化前
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824145009450733.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824145009231420.png)
若将它们的电量都变为原来的2倍,则
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824145009590904.png)
若将它们的电量都变为原来的一半,则
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824145009715943.png)
若它们之间的距离变为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824145009871404.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241450099641309.png)
将它们之间的距离变为
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824145009340391.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241450104321303.png)
点评:对于库伦定律公式要注意公式的适用条件以及公式中各个物理量的含义.
![](http://thumb2018.1010pic.com/images/loading.gif)
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