题目内容
如图,直线A为某电源的U-I图线,曲线B为某小灯泡的U-I图线,用该电源和小灯泡组成闭合电路时,电源的输出功率和电源的总功率分别是
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241345082422395.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241345082422395.png)
A.4W,8W | B.2W,4W |
C.2W,3W | D.4W,6W |
D
用该电源和小灯泡组成闭合电路时,由图象的交点知通过闭合回路的电流为2A,小灯泡两端的电压为2V,此时电源的输出功率就是小灯泡的功率P=UI=2
2=4W,由图知E=3V,电源的总功率P=EI=3
2=6W,D对,ABC错。
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134508304214.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824134508304214.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
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