题目内容
在测电源电动势和内阻实验中,由于电源内阻较小,电压表示数变化不明显,作出的
图像如图甲中A所示,这对数据处理的结果将引入较大误差,为了解决此问题,某同学在电路中串联了一定值电阻
(如图乙),作出的
图像如图甲中B所示,则此电源的电动势大小为 V,内阻为
。![](http://thumb.1010pic.com/pic2/upload/papers/20140824/2014082415243685914012.jpg)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824152436313388.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824152436406483.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824152436313388.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824152436703333.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/2014082415243685914012.jpg)
1.5V. 0.5![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824152436703333.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824152436703333.png)
试题分析:路端电压与电流的关系图像中,图线与纵坐标的交点为电源电动势,与横坐标的交点为短路电流,图线的斜率表示电源内阻,如图乙所示,此时电源内阻为R与r之和,所以r=
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824152437015787.png)
点评:难度中等,在路端电压与电流的关系图像中,要知道图线的斜率、截距代表的物理意义,能够理解图乙中的R已经归结为电源内阻
![](http://thumb2018.1010pic.com/images/loading.gif)
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