【单选题】
电池A电动势为2V,内阻为1Ω,电池B电动势为2.5V,内阻为2.5Ω,先后用A、B作电源向同一电阻供电,电流相等,这个电阻阻值R=_______。[223000000]___
A. 0.5Ω
B. 1.25Ω
C. 2.5Ω
D. 5Ω
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直流反馈是指反馈到输入电路的是输出电路中_______的直流电流或直流电压。[323010102]___
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稳压二极管与一般二极管不同,它的反向击穿是_______。[323010102]___
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稳压二极管工作于_______状态时,在电路中能起稳压作用。[323010102]___
A. 饱和
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当场间联络线的轨道电路区段有车占用时,两车场的任何一方都不能向联络线排列列车进路或调车进路
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单线站间联系电路,当接车站的接近预告轨道继电器JYGJ吸起时,反映进站信号机的接近区段空闲
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调车时当车压入信号机内方,调车信号机即自动关闭
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道岔区段的DGJ一旦落下,则FDGJ必然吸起
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