【单选题】
开关接2时,电流表的电流为___。
A. 0A
B. 10A
C. 0.2A
D. 约等于0.2A
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答案
A
解析
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应用戴维南定理求含源二端网络的输入等效电阻是将网络内各电动势___
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LC 选频振荡电路,当电路频率等于谐振频率时,电路性质为___。
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电动势为10V,内阻为2Ω的电压源变换成电流源时,电流源的电流和内阻是___
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电流为5A,内阻为2Ω的电流源变换成一个电压源时,电压源的电动势和内阻为___
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额定电压都为220V的40W、60W、100W三灯泡串联在220V的电源中,它们的发热量由大到小排列为___
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能表示容性电路电压与电流关系的相量图是___。
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B.
C.
D.
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如图判断同名端为___
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电路中___定律指出:流入任意一节点的电流必定等于流出该节点的电流。
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用戴维南定理分析电路“入端电阻”时,应将内部的电流源___处理。
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【单选题】
任何一个含源二端网络都可以用一个适当的理想电压源与一电阻___来代替。
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【单选题】
用交流电流表测得交流电流10A,则电路中电流的最大值为___。
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【单选题】
如右图所示电路中,已知各支路的电流I1=I2=10A, 则电路的总电流I为___。
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2在电场作用下,空穴与自由电子运动形成的电流方向___
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3光敏二极管应在___下工作
A. 正向电压
B. 反向电压
【单选题】
4下列半导体材料哪一种的热敏性突出“导电性受温度影响最大”?___
A. 本征半导体
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【单选题】
5用万用表电阻挡检测某一个二极管时,发现其正、反电阻均近于1000KΩ,这说明该二极管是属于___。
A. 短路状态;
B. 完好状态;
C. 断路状态;
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【单选题】
6稳压二极管是一个可逆击穿二极管,稳压时工作在___状态。
A. 正偏
B. 反偏 E、正向导通 F、截止
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7三端集成稳压器CW7812的输出电压是___。
A. 12V
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8三端集成稳压器CXX7805的输出电压是___
A. 5v
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【单选题】
9一个平衡PN结,用导线将P区和N区连起来,而导线中___。
A. 有微弱电流
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10二极管两端正向电压大于___电压时,二极管才导通。
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【单选题】
11当温度升高时,二极管的反向饱和电流 ___ 。
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12硅二极管的正向导通压降比锗二极管的___ 。
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13三端集成稳压器 CW7906的输出电压是___
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14稳压管的工作是利用伏安特性中的___。
A. 正向特性
B. 反向特性
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【单选题】
15二极管具有___
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B. 反向特性
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【单选题】
16图中D1-D3为理想二极管,A,B,C灯都相同,试问___灯最亮。
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18在单相桥式整流电容滤波电路中,设U2为其输入电压,输出电压的平均值约为___。
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19在单相桥式整流电路中,设U2为其输入电压,输出电压的平均值约为___。
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20在半波整流电容滤波电路中,设U2为其输入电压,输出电压的平均值约为___。
A. U0=0.45U2
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【单选题】
21在半波整流电路中,设U2为其输入电压,输出电压的平均值约为___。
A. U0=0.45U2
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