【判断题】【消耗次数:1】
三相异步电动机的同步转速与电源频率f、磁极对数p的关系是n1=60f/p。
正确
错误
参考答案:
复制
纠错
相关题目
【单选题】 一台三相异步电动机的磁极对数p=2,电源频率为50Hz,电动机转速n=1440r/min,其转差率s为( )。
①  1%
②  2%
③  3%
④  4%
【单选题】 三相异步电动机旋转磁场的转速与( )有关。
①  负载大小
②  定子绕组上电压大小
③  电源频率
④  三相转子绕组所串电阻的大小
【判断题】 旋转磁场的转速,即同步转速(n1)和电源频率(f1)及磁极对数(p)有关吗?
①  正确
②  错误
【单选题】 三相异步电动机的极对数为p,定子电流频率为f1,转子电流频率为f2,其转子电流所产生的基波合成磁动势的空间转速为 ( )。
①  60f1/2p
②  60f1/p
③  60f2/2p
【判断题】 三相异步电动机在进入回馈制动时,电动机转子的转速低于同步转速。
①  正确
②  错误
【判断题】 三相异步电动机的同步转速和转轴速度一样?
①  正确
②  错误
【单选题】 一台三相异步电动机,定子旋转磁场磁极对数为2,若定子电流频率为100Hz,其同步转速为( )。
①  1200r/min
②  1500r/min
③  2000r/min
④  3000r/min
【判断题】 三相异步电动机的转子回路串电阻并不改变同步转速。
①  正确
②  错误
【单选题】 三相异步电动机转子的转速( )旋转磁场的转速。
①  低于
②  高于
③  等于
【判断题】 三相异步电动机的转子与定子旋转磁场以相同的方向、不同的转速旋转,存在转差率,所以叫三相异步电动机。
①  正确
②  错误
随机题目
【单选题】 Lifelong learning is both formal and non-formal; and the boundaries between face-to-face teaching and ___________ education are increasingly blurred.
①  lifelong
②  formal
③  distance
④  far
【单选题】 I hope you are making ________ for continuous education in your life.
①  room
②  vacancy
③  place
④  like
【单选题】 Some universities offer free, non-credit MOOCs __________ to anyone in the world.
①  useful
②  available
③  easy
④  careful
【单选题】 Well, that’s to say, every coin has two sides, ________ technology.
①  so is
②  so does
③  so has
④  so did
【单选题】 _________ the regular classes, you can also attend many different seminars and take part in many extracurricular activities.
①  Except for
②  Including
③  Apart from
④  Included
【单选题】 —How long have you been graduated from your college?— .
①  Yes, I’ve been graduated
②  I’ve been graduated for five years
③  I graduated from my college last year
④  I graduat from my college last year
【单选题】 The advancement of technology has boosted the pace of our lives, and requires us to learn ___________ every day just to stay current in the workplace.
①  something new
②  new something
③  everything
④  anything
【单选题】 I have _________ some courses and software to my Smartphone, and I find they are very interesting and easy to use.
①  uploaded
②  downloaded
③  copied
④  copy
【单选题】 Mr. Wang, _________, is coming up to us.
①  slowly
②  our new teacher
③  he is our new teacher
④  slow
【单选题】 — I often feel lonely when I engage in my online learning. ________?— I join the online course community.
①  How do you solve this problem
②  How do you think about it
③  How often do you engage in online learning
④  When do you engage in online learning