问题
判断题
对于变频器,如果输出频率降低,电机转速将跟随频率同样降低。这时会产生制动过程。由制动产生的功率将返回到变频器侧。这些功率可以用电阻发热消耗。()
答案
参考答案:对
对于变频器,如果输出频率降低,电机转速将跟随频率同样降低。这时会产生制动过程。由制动产生的功率将返回到变频器侧。这些功率可以用电阻发热消耗。()
参考答案:对
在B栏中找出与A栏问题相对应的答语,将序号填在括号里。 |
A ( ) 1. What's the dog doing? ( ) 2. What are they doing? ( ) 3. Can geese swim? ( ) 4. Can I speak to your mom? ( ) 5. What is your mother doing? ( ) 6. Is your father reading a newspaper? | B A. Yes, they can. B. It's swinging. C. They are dancing. D. She is washing the clothes. E. Sure. F. Yes, he is. |