题目内容
在如图所示电路中,R1、R2、R3均为可变电阻。当开关S闭合后,两平行金属板M、N间有一带电液滴正好处于静止状态,为使带电液滴向上做加速运动,可采取的措施是
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241512193832695.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241512193832695.jpg)
A.增大R1 | B.减小R2 |
C.减小R3 | D.增大M、N间距 |
B
试题分析:当增大
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824151219446327.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824151219446327.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824151219446327.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824151219633361.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824151219758365.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824151219758365.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824151219633361.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824151219758365.png)
点评:电阻R1与两平行板相串联,由于没有电流,所以没有电势降落,因此可将R1电阻去除.当改变间距时,会导致两板间的电容变化.
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目