把两只灯泡并联后接到电源上,闭合开关,发现灯泡L1比L2亮,则下

把两只灯泡并联后接到电源上,闭合开关,发现灯泡L1L2亮,则下列说法正确的是( 

A.通过L1的电流大         B.通过L2的电流大     

C.L1两端的电压大         D.L2两端的电压大

答案

A思路点拨:灯泡的亮暗与灯的实际功率有关,L1L2亮说明L1的实际功率比L2大。并联时灯两端的电压相等,根据P=UI可得,流过L1的电流比L1大。

全程精解:A

误区分析:在电学中首先要分析电路的连接方式,不同电路的电流、电压和电阻的关系是不同的。

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