题目内容
在如右图所示的电路中,E为电源,其内阻为r,L为小灯泡(其灯丝电阻可视为不变),
、
为定值电阻,
为光敏电阻,其阻值大小随所受照射光强度的增大而减小,
为理想电压表.若将照射
的光的强度减弱,则( )
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408242146264823167.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824214621802327.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824214623019361.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824214623736365.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824214624547469.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824214623736365.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408242146264823167.jpg)
A.电压表的示数变大 | B.小灯泡消耗的功率变小 |
C.通过R2的电流变小 | D.电源内阻消耗的电压变大 |
B
试题分析:若将照射
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824214623736365.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824214623736365.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824214623019361.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824214623019361.png)
故选B
点评:做此类型题目一般步骤为:从部分变化电路,推出整体电路变化,再推出另外所需部分电路的变化
![](http://thumb2018.1010pic.com/images/loading.gif)
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