小明在参观水库时,看到水库的水位自动报警器如图所示。他分析了

小明在参观水库时,看到水库的水位自动报警器如图所示。他分析了这个装置的工作原理:由于AB都是碳棒,当水位到达A位置时,“控制电路”接通,电磁铁产生         ,吸下衔铁,此时“工作电路”中         灯发光,发出报警信号。

答案

磁性 

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