题目内容
在如图所示的电路中,当可变电阻R的阻值增大时 ( )
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241408526181703.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241408526181703.png)
A.AB两点间的电压减小 |
B.通过R1的电流I1增大 |
C.通过R的电流I增大 |
D.通过R的电流I减少 |
D
考查电路的动态分析问题。当
增大时,
增大,
增大,有
,因
、
不变,
增大时,
减小,即I1减小,B错误;而
,因
、
不变,
减小,故
增大;由
,因
不变而
减小,则
减小;由
,因
增大而
减小,故
增大;由
,因
增大,
不变,则
增大;由
,因
减小,
增大,
减小。可见,当
增大时,
增大,I1减小,
减小,故选项D正确。
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140852711303.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140852789420.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140852867402.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140852961745.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853039332.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853117260.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140852867402.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853242368.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853288757.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853039332.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853117260.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853242368.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853429460.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853522585.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853585327.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853242368.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853678350.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853710698.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853429460.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853678350.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853850443.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853897767.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853850443.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853975359.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140854022386.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140854068565.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140853242368.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140854022386.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140854271343.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140852711303.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140854365446.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140854458265.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目