【判断题】【消耗次数:1】
由变压器一相电动势表达式可知,相量落后于相量900
正确
错误
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相关题目
【判断题】 由变压器一相电动势表达式<imgwidth="120"height="26"v:shapes="对象_x0020_30"src="http://wljy.whut.edu.cn:80/uploadfiles/word/djytdpdt.files/image026.png">可知,<imgwidth="18"height="24"v:shapes="对象_x0020_31"src="http://wljy.whut.edu.cn:80/uploadfiles/word/djytdpdt.files/image028.png">相量落后于<imgwidth="26"height="26"v:shapes="对象_x0020_32"src="http://wljy.whut.edu.cn:80/uploadfiles/word/djytdpdt.files/image030.png">相量900
①  正确
②  错误
【判断题】 三相变压器的联结组别是指高压、低压绕组对应的线电动势之间相位差。
①  正确
②  错误
【单选题】 三相交流电路:由三个频率相同、最大值(或有效值)相等,在相位上互差( )度电角的单相交流电动势组成的电路,这三个电动势称为三相对称电动势。
①  45
②  60
③  90
④  120
【判断题】 由于正弦量与相量存在对应关系,所以相量等于正弦量。
①  正确
②  错误
【单选题】 任意一个相量乘以j相当于该相量()。
①  逆时针旋转90o
②  逆时针旋转60o
③  逆时针旋转60o
④  顺时针旋转90o
【单选题】 对于三相变压器,额定电流指的是( )。
①  线电流
②  相电流
③  负载电流
【判断题】 因为正弦量可以用相量来表示,所以说相量就是正弦量。
①  正确
②  错误
【判断题】 下列是隐极式同步电动机的电动势相量图。<img src="20190822/1566469003766443.jpg" title="1566469003766443.jpg" alt="1566468980(1).jpg"/>
①  正确
②  错误
【判断题】 正弦量可以用相量表示,因此可以说,相量等于正弦量。
①  正确
②  错误
【单选题】 一台三相变压器的联接组别为Y,y0,其中“Y”表示变压器的( )。
①  高压绕组为三角形接法
②  高压绕组为星形接法
③  低压绕组为星形接法
④  低压绕组为三角形接法
随机题目
【单选题】 The fact remains  () we are behind many others.
①  that
②  why
③  where
④  how
【单选题】 There were two small rooms in the house, _______ served as a bathroom.
①  the smallest of which
②  the smallest of them
③  the smaller of which
④  smallest of that
【单选题】 The young people are _____ of their responsibility toward society.
①  consistent
②  conscious
③  sensitive
④  sensual
【单选题】 Did the medicine make you feel better?No. The more _______, _______ I feel.
①  medicine I take; and the worse
②  medicine I take; the worse
③  I take medicine; the worse
④  I take medicine; worse
【单选题】 Large fish usually _____ small fish.
①  gather
②  take on
③  feed on
④  organize
【单选题】 I often ______ the cooking for my family, but recently I have been too busy to do it.
①  will do
②  do
③  am doing
④  had done
【单选题】 The plane was about to _________, and yet l left my ticket behind.
①  take on
②  take off
③  take up
④  take in
【单选题】 Global warming threatens the _______ of the whole human race.
①  summit
②  superiority
③  survival
④  status
【单选题】 So little ____ with each other that the neighbors could not settle their difference.
①  agreed did they
②  did they agree
③  they agree
④  they did agree
【单选题】 Putting in a new window will _____ cutting away part of the roof.
①  include
②  involve
③  contain
④  comprise