题目内容
如图所示,四个灯泡的电阻分别是R1=R3=10欧,R2=R4=30欧,分别用P1、P2、P3、P4表示这四个灯泡的电功率,那么
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824144857065486.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824144857065486.png)
A.P1>P2>P3>P4 | B.P1>P3>P2>P4 |
C.P4>P3>P2>P1 | D.P2>P1>P3>P4 |
D
试题分析:灯泡R3和R4为并联关系,由电功率公式
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824144857128607.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824144857190481.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824144857253605.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824144857190481.png)
点评:本题可用两两比较的方法,根据并联电压相同,串联电流相同,利用不同的连接关系,不同的公式进行判断
![](http://thumb2018.1010pic.com/images/loading.gif)
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