题目内容
如图所示,电源电动势为E,内阻为r,不计电压表和电流表内阻对电路的影响,当电键闭合后,两小灯泡均能发光。在将滑动变阻器的触片逐渐向右滑动的过程中,下列说法正确的是
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250018471932717.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250018471932717.jpg)
A.小灯泡L1、L2均变暗 |
B.小灯泡L1变亮,小灯泡L2变暗 |
C.电流表A的读数变小,电压表V的读数变大 |
D.电流表A的读数变大,电压表V的读数变小 |
BC
试题分析:滑动变阻器的滑片向右移动时,接入电路的阻值变大,所以电路中的外电阻R变大,由闭合电路的欧姆定律
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001847209567.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001847224616.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001847240549.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825001847240580.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
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