【判断题】旋转磁场是一种大小不变,且以一定转速旋转的磁场。
【多选题】关于三相异步交流电机,以下叙述正确的是( )。
A.
所谓旋转磁场,就是一种极性和大小不变且以一定转速旋转的磁场;
B.
当对称三相电流通入对称三相绕组时,必然会产生一个大小不变、转速一定的旋转磁场;
C.
当三相异步电动机有两对磁极时,三相电流随时间变化一个周期,旋转磁场转过1/2转;
D.
在三相异步电动机中实现机电能量转换的前提是产生旋转磁场。
【单选题】在采用计划成本分配法分配辅助生产费用时,辅助生产的成本差异可记入:()
【单选题】How many yearsmust a British student study in the university?
【简答题】听下面一段材料,回答第1至3题。 1. How many children are there in the man's family? [ ] A. 2. B. 3. C. 4. 2. What was the man before going to New York? [ ] A. A teacher. B. A doctor. C. A student. 3. Where d...
【单选题】在辅助生产费用采用计划成本分配法时,为了简化计算工资,辅助生产劳务的成本差异一般全部计入( )
【简答题】听下面一段材料,回答第1-3题。 1. How many brothers and sisters does the woman have? A. Nine. B. Seven. C. Six. 2. What does the woman's brother Raymond do in the United States? A. He's a student. B. He's a busines...
【判断题】旋转磁场值得是一种记性和大小不变,且以一定转速旋转的磁场。
【简答题】A. Listen to the dialogue and answer the following questions. (发送语音作答) 1. Why does the student want to know how to do market research? 2. How can one choose a specific method to do market research? 3....