【单选题】下述对有功功率的描述不正确的是______
A.
单口网络的有功功率表示该单口网络实际消耗的功率
C.
单口网络的有功功率等于该单口网络中所有电阻消耗的功率之和
D.
如果单口网络的端口电压与电流为关联参考方向,则其有功功率等于端口电压、电流幅值的乘积再乘以单口网络的功率因数
【单选题】用万用表交流电压档 ( 频率上限仅为 5kHz) 测量频率高达 500kHz 、 10V 左右的高频电压,发现示值还不到 2V ,该误差属于
【单选题】(2017·山西)实验表明,磁体能吸引1元硬币,对这种现象解释正确的是( )
【简答题】阅读理解。 Bob Pearson is an old man. He has two big houses and a new car. He has no wife.But he is a father of four children. He has two sons and two daughters. One son is from England. His name ...
【判断题】Pearson has pieced together the work of hundreds of
researchers around the world to produce a unique millennium technology calendar
that gives the latest dates when we can expect hundreds of key break...