【单选题】在图示电路中,A1、A2、V1、V2均为交流表,用于测量电压或电流的有效值I1、I2、U1、U2,若I1=4A,I2=2A,U1=l0V,则电压表V2的读数应为:
【单选题】At nine o'clock in the evening the parade began.句中单词()用升调来读。
【简答题】vary (1) The medical tests showed some _____________ in the baby’s heart rate. (2) The author gave _____________ reasons for having written the book. (3) Work on the production line is monotonous (单调的...
【简答题】Work on the production line is monotonous ( 单调的 ) and lacks . (vary)
【单选题】稳压管电路如图所示,稳压管D Z1 的稳定电压U Z1 =12V,D Z2 的稳定电压为U Z2 =6V,则电压U 0 等于()
【单选题】图 2-69 所示电路中,图 ( b ) 所示为图 (a) 所示电路的戴维南等效电路,电阻为20Ω,则 U 0 、 R 0 分别为
【单选题】Some day there will be a robot that takes the drudgery (苦工,单调沉闷的工作) out of housework—and even cleans windows, but how soon such a robot will emerge is anybodys guess. Mr. Joseph Engelberger, President...
【单选题】图1所示电路的等效电压源电路如图2所示,则图2中U s 和R 0 的值分别是()。