【判断题】【消耗次数:1】
异步电动机的启动转矩Y接降压启动为△接直接启动的三分之一?
正确
错误
参考答案:
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相关题目
【判断题】 异步电动机启动方式有直接启动和降压启动两种方式?
①  正确
②  错误
【多选题】 三相鼠笼式异步电动机的启动方式有_______。
①  全压启动
②  降压启动
③  半压启动
④  同步启动
【判断题】 异步电动机的启动转矩与定子电压平方成正比?
①  正确
②  错误
【判断题】 7.5KW以上三相异步电动机启动不需要其它设备可以直接启动?
①  正确
②  错误
【单选题】 三相异步电动机的启动控制方式有两种: 一种是直接启动控制;另一种是()。
①  间接启动控制
②  降压启动控制
【单选题】 三相笼形异步电动机启动电流大的原因是( )。
①  电压过高
②  负载过重
③  转差率大
④  电压过低
【单选题】 三相电动机启动时,在电动机的定子绕组上串联电阻,待启动完成后,再将电阻短接,全压运行的方式是( )。
①  定子绕组串接电阻降压启动
②  自耦变压器降压启动
③  Y(星)—△(三角)降压启动
④  延边△降压启动
【单选题】 绕线式三相异步电动机,转子回路中可以外串三相对称电阻,以增大电动机的启动转矩,启动结束后可以切除外串电阻,电动机的效率从而受到受影响。
①  正确
②  错误
【判断题】 电动机启动时希望其启动电流小、启动转矩大?
①  正确
②  错误
【判断题】 电源容量在180kW以上,电动机功率在7kW以下的三相异步电动机可采用直接启动。
①  正确
②  错误
随机题目
【单选题】 Ill visit you whenever I will get the chance. Identify the mistake in the sentence.
①  visit
②  whenever
③  will
④  chance
【单选题】 It is difficult for us to learn a lesson in life [] youve had that lesson.
①  until
②  after
③  when
④  since
【单选题】 Danish bacon and eggs [] a good solid English breakfast.
①  makes
②  make
【单选题】 She happily deposits the money she has earned teaching English in her savings account. Find any misplaced modifier in the sentence
①  happily
②  she has earned
③  in her savings account
【单选题】 Well have a picnic in the park this Saturday [] it rains or it is very cold.
①  since
②  if
③  until
④  unless
【单选题】 His family [] divided opinions on many issues.
①  is
②  are
【单选题】 There were some chairs left over[] everyone had sat down.
①  when
②  until
③  that
④  where
【单选题】 These candidates have vague notions of serving the company, [] they have never taken trouble to find out the actual tasks they will be required to do.
①  or
②  and
③  but
④  so
【单选题】 Which sentence is correct?
①  On entering the classroom, the students stood up and said, Good morning!
②  On entering the classroom, the teacher was greeted by the students with Good morning!
【单选题】 When their party came back to the camp site, ours arrrived two hours earlier. Identify the mistake in the sentence.
①  When
②  ours
③  arrived
④  earlier