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【简答题】
如图所示的液位报警装置的部分电路。u i是液位传感器送来的信号,UR是参考电压,如果液位超过上限,即ui超过正常值时,报警灯亮。试说明电路的工作原理,二极管D和电阻R的作用。
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A.
it has a beautiful body
B.
it has big eyes
C.
it can look straight ahead
D.
it can turn its neck
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A.
正确
B.
错误
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