【判断题】【消耗次数:1】
直流电动机弱磁升速的前提条件是恒定电动势反电势不变。
正确
错误
参考答案:
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相关题目
【判断题】 直流电动机弱磁升速的前提条件是恒定电枢电压不变
①  正确
②  错误
【单选题】 直流电动机启动后,其反电动势导致线圈电流( )。
①  大幅减少
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【单选题】 直流电动机启动后,其反电动势大小与转子速度( )。
①  没有关系
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③  成反比
【判断题】 直流电动机中包括鼠笼式电动机。
①  正确
②  错误
【单选题】 直流电动机启动后,其反电动势会( )电源加在线圈上的部分电压。
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【判断题】 直流电动机运行于电动状态时,产生感应电动势是反电动势,产生的电磁转矩T是反抗性的。
①  正确
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【单选题】 直流电动机的过载保护就是电动机的()
①  A过电压保护
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③  C超载保护
④  D短路保护
【单选题】 直流电动机中电枢感应电势和电枢电流方向?
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【单选题】 直流电动机调速方法不包含(?? ?)。?
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【单选题】 直流电动机常用()方法实现反转。
①  改变磁通方向
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随机题目
【单选题】 I really appreciate ____ to help me, but I am sure that I can manage by myself.
①  you to offer
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【单选题】 Half of the money____ your brother. ?
①  belong to ?
②  belong ?
③  belongs to ?
④  belongs?
【单选题】 25. A pilot should be responsible ____ the safety of all the passengers on board.
①  against
②  for
③  at
④  with
【单选题】 After ten years, all these youngsters became____.
①  grown-up
②  grown-ups
③  growns-ups
④  growns-up
【单选题】 We’ll go out as soon as I’ve ____ the kitchen.
①  sent for
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③  done with
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【单选题】 “I haven’t read ____ of the last four chapters, so I know little about them.”
①  something
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【单选题】 Wealthy ____ he was, the governor would not spend a penny on such things.
①  as
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【单选题】 —Guest: Oh, it’s ten o’clock. I’d better go now.—Host: ____.
①  OK. Please walk slowly and take care.
②  Why do you want to go now? Don’t you want to stay?
③  Yeah, it’s really late. Why not immediately?
④  Won’t you stay for another cup of coffee?