【简答题】有些三相异步电动机有380/220V两种额定电压,定子绕组可以接成星形,也可以接成三角形,试问在什么情况下采用这种或那种连接方法?采用这两种连接法时,电动机的额定值(功率、相电压、线电压、相电流、线电流、效率、功率因数、转速等)有无改变?
【单选题】There have always been a small _________ of women who would pursue men directly, but traditionally, dating has been led by the male species. A)amount B) sum C) deal D) handful
【单选题】企业应当按照交易或者事项的经济实质进行会计确认、计量和报告,不应仅以交易或者事项的法律形式为依据,下列体现了实质重于形式的是( )。
【单选题】Steve barely said a handful of words during the first half hour.at is the meaning of ‘a handful of’ in the sentence?
【判断题】苔藓植物的雌性生殖器官叫颈卵器,故苔藓植物是一种颈卵器植物。
【简答题】一台三相异步电动机的额定电压是380V,当三相电源线电压是380V时,定子绕组应采用那种连接?当三相电源线电压为660V时,应采用那种连接方法?
【单选题】There have always been a small _________ of women who would pursue men directly, but traditionally, dating has been led by the male species. A)amount B) sum C) deal D) handful
【单选题】三相异步电动机定子绕组采用()的连接方法。