【判断题】【消耗次数:1】
电动机点动与长动控制环节的区别是电动机长动有自锁环节。
正确
错误
参考答案:
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相关题目
【单选题】 点动与长动的区别是_______。
①  有零压保护环节
②  无零压保护环节
③  无自锁环节
④  有过载保护环节
【单选题】 所谓点动控制是指按下按钮,电动机就得电运转;松开按钮,电动机就失电停转。
① 
② 
【判断题】 长动和点动的主要区别在于松开启动按钮后,电动机能否继续保持得电运转的状态。
①  正确
②  错误
【单选题】 设电动机某一转动方向的转速n为正,则约定电动机转矩TM与n_________的方向为______。
①  一致、正向
②  一致、反向
③  相反、正向
④  以上都不对
【单选题】 交流主轴电动机可称为()电动机。
①  三相异步电动机
②  三相同步电动机
③  交流永磁同步电动机
④  以上选项都不对
【单选题】 鼠笼式电动机与绕线式电动机的的比较的特点在于()。
①  不能人为改变电动机的机械特性;
②  结构简单、价格低廉、工作可靠;
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【判断题】 三相异步电动机当采用Y--D换接起动时,电动机的起动电流可降为直接起 动的1/3。
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②  错误
【单选题】 检查电动车窗左后电动机时,用蓄电池的正负极分别接电动机连接器端子后,电动机转动,互换正负极和端子的连接后,电动机反转,说明( )。
①  电动机状况良好
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③  电动机损坏
【单选题】 在机床电力拖动中要求油泵电动机启动后主电动机才能运行,接触器KM1控制油泵电动机,接触器KM2控制主电动机,则在控制电路中必须( )。
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②  KM1的动断触点串入KM2的线圈电路中
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④  KM2的动合触点串入KM1的线圈电路中
【判断题】 电动机处于电气制动状态,电动机的电磁转矩和电动机的旋转方向相同。
①  正确
②  错误
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【单选题】 Eeveryone is working harder and living a happier life now, _________ ?
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【单选题】 Most people come to realize that it is about time the government ____ further measures to control the population.
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【单选题】 --_______ I put my coat here ?-- Sorry, you ________ .
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③  neednt
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【单选题】 My____ brother is five years ____ than I.
①  elder … older
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③  older….old
④  elder…elder
【单选题】 By the end of last month, she _____ over five hundred letters of congratulation from different parts of the world.
①  would received
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【单选题】 -- Im taking my driving test tomorrow.-- _________ !
①  Cheers
②  Congratulations
③  Come on
④  Good luck
【单选题】 In order to _______ your goals, you must work hard.
①  make
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③  require
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【单选题】 _______ the English examination, I would have gone to the concert last Sunday.
①  In spite of
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③  Because of
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【单选题】 By the time he was twelve, Edison____ to make a living by himself.
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【单选题】 The popular singer who had been praised very highly____ to be a great disappointment.
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