题目内容
如图所示,P、Q是两个电量相等的正的点电荷,它们连线的中点是O,A、B是中垂线上的两点,
,用
、
、
、
分别表示A、B两点的场强和电势,则( )
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241422150051927.jpg)
A.
可能大于
,
一定大于![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214943378.png)
B.
不一定大于
,
一定大于![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214943378.png)
C.
一定大于
,
不一定大于![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214943378.png)
D.
不一定大于
,
不一定大于![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214943378.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214319506.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214475358.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214802366.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214896382.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214943378.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241422150051927.jpg)
A.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214475358.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214802366.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214896382.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214943378.png)
B.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214475358.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214802366.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214896382.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214943378.png)
C.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214475358.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214802366.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214896382.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214943378.png)
D.
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214475358.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214802366.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214896382.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824142214943378.png)
AB
两等量的同种点电荷在连线中点O处和离O点无穷远处的场强均为零,而A、B处的场强是指两正点电荷分别在该点产生的场强的矢量和,根据平行四边形定则可知合场强的方向向上,所以从O点起沿中垂线到无穷远处场强先增大后减小,因A、B的具体位置不确定,所以场强大小不确定,沿着场强的方向电势降低,所以φA>φB,AB正确;
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目