相关试题
【判断题】
欠压保护可以防止断电后，电源突然恢复时，造成电动机自动启动
【判断题】
电压互感器是供配电系统中配合测量仪表和继电保护使用的一种特殊变压器
【判断题】
同一发电车各发电机组要均衡使用，个机组运转时差最大不得超过１００H
【判断题】
GN型蓄电池中修后，电解液液面应高出极板肩10－20mm
【判断题】
当环境温度低于1６℃时，严禁开启空调设备制冷
【判断题】
全列空调列车额定负载总和不得超过发电车额定输出功率
【判断题】
当环境温度低于0℃时，须开启电伴热装置
【判断题】
蓄电池用蒸馏水含铁离子不大于５．０mg/L
【判断题】
毛细管可将高温高压液体变成低温低压液体
【判断题】
大修后，餐车电冰箱控制箱的金属外壳须换新品
【判断题】
KP-2A型控制箱中晶闸管SCR1的控制角大于导通角
【判断题】
流过电力连接线的电流量不得大于电力连接线的额定容量
【判断题】
旅客列车运行途中，严禁关闭电子防滑装置、轴温报警装置和其他报警装置
【判断题】
途中因供电装置故障或长时间停留时，车辆乘务员可酌情减少用电负荷
【判断题】
车速越高、负载越小时，激磁电流越小、激磁电压越低
【判断题】
万用电桥只能测量电阻，不能测量电容和电感
【判断题】
TFX电子防滑系统适用于非空气制动的铁道车辆上使用
【判断题】
三相四线交流电源星型接法中，线电压等于相电压的
【判断题】
异步电动机的旋转磁场的转速大小只与磁极对数有关
【判断题】
DC600V供电列车运用列车绝缘要求是用1000V兆欧表测量，在相对湿度大于60℅时，线间电阻≥2兆欧，线地间电阻≥1兆欧
【判断题】
DC600V供电列车运用列车绝缘要求是用1000V兆欧表测量，在相对湿度大于85℅时，线间电阻≥0.6兆欧，线地间电阻≥0.3兆欧
【判断题】
DC600V供电列车运用单车绝缘要求是用1000V兆欧表测量，在相对湿度小于60℅时，线间电阻≥4兆欧，线地间电阻≥2兆欧
【判断题】
DC600V供电列车运用单车绝缘要求是在相对湿度小于85℅时，线间电阻≥1兆欧，线地间电阻≥0.5兆欧
【判断题】
AC380V供电列车运用列车绝缘要求是用500V兆欧表测量，在相对湿度小于60℅时，线间电阻≥2兆欧，线地间电阻≥1兆欧
【判断题】
AC380V供电列车运用列车绝缘要求是用500V兆欧表测量，相对湿度大于85℅时，线间电阻≥0.38兆欧，线地间电阻≥0.22兆欧
【判断题】
AC380V供电列车运用单车绝缘要求是用500V兆欧表测量，在相对湿度大于60℅时，线间电阻≥4兆欧，线地间电阻≥2兆欧
推荐试题
【单选题】
Although he had looked through all the reference material on the subject, he still found it hard to understand this point and her explanation only _________ to his confusion.___
A. extended
B. amounted
C. added
D. turned
【单选题】
A completely new situation will ___________ when the examination system comes into existence.___
A. arise
B. rise
C. raise
D. arouse
【单选题】
Cancer is second only __________ heart disease as a cause of death.___
A. of
B. to
C. with
D. from
【单选题】
The manager needs an assistant that he can _________ to take care of problems in his absence.___
A. count on
B. count in
C. count up
D. count out
【单选题】
We gave out a cheer when the red roof of the cottage came __________ view.___
A. from
B. in
C. before
D. into
【单选题】
They took ________ measures to prevent poisonous gases from escaping.___
A. fruitful
B. beneficial
C. valid
D. effective
【单选题】
Doing your homework is a sure way to improve your test scores, and this is especially true _______ it comes to classroom tests.___
A. when
B. since
C. before
D. after
【单选题】
In developing countries people are _______ into overcrowded cities in great numbers.___
A. breaking
B. filling
C. pouring
D. hurrying
【单选题】
There are other problems which I don't propose to ____________ at the moment.___
A. go into
B. go around
C. go for
D. go up
【单选题】
It is quite necessary for a qualified teacher to have good manners and _________ knowledge.___
A. extensive
B. expansive
C. intensive
D. expensive
【单选题】
I'm not sure whether I can gain any profit from the investment, so I can't make a(n) ______ promise to help you.___
A. exact
B. defined
C. definite
D. sure
【单选题】
The sports meet, originally due to be held last Friday, was finally ________ because of the bad weather.___
A. set off
B. broken off
C. worn off
D. called off
【单选题】
It has been revealed that some government leaders _______ their authority and position to get illegal profits for themselves.___
A. employ
B. take
C. abuse
D. overlook
【单选题】
Shelly had prepared carefully for her biology examination so that she could be sure of passing it on her first ________.___
A. intention
B. attempt
C. purpose
D. desire
【单选题】
The store had to _______ a number of clerks because sales were down.___
A. lay out
B. lay off
C. lay aside
D. lay down
【单选题】
All the students in this class passed the English exam ________ the exception of Li Ming.___
A. on
B. in
C. for
D. with
【单选题】
Writing is a slow process, requiring _______ thought, time, and effort.___
A. significant
B. considerable
C. enormous
D. numerous
【单选题】
Lightning is a ______ of electrical current from a cloud to the ground or from one cloud to another.___
A. rush
B. rainbow
C. rack
D. ribbon
【单选题】
I caught a ________ of the taxi before it disappeared around the corner of the street.___
A. vision
B. glimpse
C. look
D. scene
【单选题】
Students or teachers can participate in excursions to lovely beaches around the island at regular _________.___
A. gaps
B. rate
C. length
D. intervals
【单选题】
Physics is ________ to the science which was called natural philosophy in history.___
A. alike
B. equivalent
C. likely
D. uniform
【单选题】
The new appointment of our president _______ from the very beginning of next semester.___
A. takes effect
B. takes part
C. takes place
D. takes turns
