如图所示为某城市道路上安装的光控节能路灯的原理图,当周围环境的亮暗程度发生变化时,电路中的光敏电阻阻值会随光照增强而变小。已知电源电动势为
,内阻为
,
为光敏电阻,A、B为两个路灯。当周围环境变亮时,闭合开关S,下列判断正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11bc05f41215f9894e11d1df0465751a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93548b1031bb3a147b05d626d0050ee1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/2/2df4e329-f400-4926-a8a7-13b4304c9e96.png?resizew=147)
A.两灯都变亮 | B.电源的总功率变小 |
C.电源的输出功率变小 | D.电源的效率变低 |
更新时间:2023-08-31 15:57:28
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【推荐1】某学校新安装了一批节能路灯如图甲所示,该路灯通过光控开关实现自动控制,电灯的亮度可随周围环境的亮度改变而改变。图乙为其内部电路简化原理图,电源电动势为E,内阻为r,
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A.A灯、B灯都变亮 |
B.电源内阻消耗的功率变大 |
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D.![]() ![]() |
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【推荐2】电路图如图所示,电源电动势为
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A.![]() ![]() |
B.![]() |
C.![]() ![]() |
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【推荐1】如图所示电路中,电源的内电阻为r,
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