【判断题】
调整25HZ相敏轨道电路时，当轨道电压不标准，可以对受电端轨道变压器的抽头进行调整
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相关试题
【判断题】
UM71型轨道电路的绝缘节为机械绝缘节而不是电气绝缘节
【判断题】
UM71轨道电路两端的补偿电容距电器绝缘区空心线圈的距离相等，且应不小于48m、不大于98m
【判断题】
有移频轨道电路区段的特大桥梁护轮轨，除两端需装设绝缘外，应每200m装设一绝缘
【判断题】
电气化区段凡能造成扼流变压器Ⅱ次开路的，都应做好防护
【判断题】
电气化区段相邻轨道电路可以连续加设扼流变压器
【判断题】
电容器串联时，等效电容量等于各个串联电容的容量之和
【判断题】
使用万用表测量电流时，将开关旋钮置于测量电流的位置上，并联在被测电路上即可
【判断题】
两个不同阻值的电阻并联，其总电阻值比小电阻的大，比大电阻的小
【判断题】
两个110V、25W的照明灯泡并联之后可以接在220V电源上
【判断题】
电源电动势的大小由电源本身的性质决定，与外电路无关
【判断题】
电容器串联后等效电容的倒数等于各电容的倒数和
【判断题】
金属涂镀层的形成，从本质上讲和电镀是不相同的
【判断题】
毫伏表的灵敏度较高，所以使用毫伏表能精确地量出交、直流电压值
【判断题】
为了提高反相器的负向抗干扰能力，应使晶体三极管工作在深度饱和状态
【判断题】
基本RS触发器有0或1两种状态。当RD=0、SD=1时，无论触发器初态如何，触发器被置1
【判断题】
在双稳态触发器电路中，晶体三极管只有饱和及截止两种状态，因此在工作时晶体三极管不需经过放大工作状态
【判断题】
三端稳压器有一个输入端、一个输出端、一个公共端
【判断题】
凡大小和方向都随时间变化的电压和电流，称为正弦交流电压和正弦交流电流
【判断题】
四显示自动闭塞在列车追踪间隔时间内，一般划分为不少于4个闭塞分区排列信号机
【判断题】
ZP·W1-18型移频自动闭塞发送盒采用“N+1”热备方式，接收盒采用“1+1”或“N+1”热备方式
【判断题】
非电化四信息移频振荡器有两个主振频率，△f为45Hz
【判断题】
非电化四信息移频自动闭塞，闭塞分区被占用或轨道电路失效时，防护该闭塞分区的通过信号机应自动关闭
【判断题】
移频电源设备，区间和站内不能通用，在型号上有所区别
【判断题】
非电化四信息移频发送设备仅用24V直流稳压电源
【判断题】
集中式移频自动闭塞接收设备防雷由二级组成
【判断题】
电气化区段移频自动闭塞(ZP-89型)，移频发送盘移频频率的变化为±1HZ
【判断题】
ZP.Y2-18型移频自动闭塞区间发送盘在“低出”测试孔测输出低频频率，误差应小于或等于±3‰
【判断题】
ZP.Y2-18型移频自动闭塞区间发送盘在“移频”测试孔测中心频率和上、下边频，误差应小于或等于±1Hz
【判断题】
ZP·W1-18型移频自动闭塞系统传输电缆长度设置7.5km
【判断题】
防锈漆是一种含防锈颜料且具有防锈能力的涂料
【判断题】
微机电缆绝缘的测试可以用MΩ表直接测量
【判断题】
信号电缆芯线间绝缘电阻、任一芯线对地绝缘电阻，使用高阻MΩ表测试，每km不小于400MΩ
【判断题】
电气化区段处理电缆故障时必须先将断开的两端外皮进行临时(这时要进行人身安全防护)接地处理，然后再进行电缆作业
推荐试题
【单选题】
As to the greenhouse effect, the author ________.___
A. share the same view with the scientist
B. is uncertain of its occurrence
C. rejects it as being ungrounded
D. thinks that it will destroy the world soon
【单选题】
The underlined word "offset" in the second paragraph could be replaced by _________.___
A. slip into
B. make up for
C. set up
D. catch up with
【单选题】
It can be concluded that ____________.___
A. raising the world's temperature only a few degrees would not do much harm to life on earth
B. lowering the world's temperature merely a few degrees would lead major farming areas to disaster
C. almost no temperature variations have occurred over the past decade
D. the world's temperature will remain constant in the years to come
【单选题】
This passage is primarily about __________.___
A. the greenhouse effect
B. the burning of fossil fuels
C. the potential effect of air pollution
D. the likelihood of a new ice age
【单选题】
What is the major function of paragraph 1?___
A. To arouse the reader's concern.
B. To introduce the theme of the whole passage.
C. To summarize the whole passage.
D. To state the primary uses of TV.
【单选题】
Television, as a source of entertainment, is ________.___
A. not very convenient
B. very expensive
C. quite dangerous
D. relatively cheap
【单选题】
Why are some people against TV?___
A. Because TV programs are not interesting.
B. Because TV viewers are totally passive.
C. Because TV prices are very high.
D. Because TV has both advantages and disadvantages.
【单选题】
One of the most obvious advantages of TV is that _________.___
A. it keeps us informed
B. it is very cheap
C. it enables us to have a rest
D. it controls our lives
【单选题】
According to the passage, whether TV is good or not depends on ___________.___
A. its quality
B. people's attitude towards it
C. how we use it
D. when we use it
【单选题】
What regulation was issued by New York State concerning beverage containers?___
A. A fee should be charged on used containers for recycling.
B. Throwaways should be collected by the state for recycling.
C. Consumers had to pay for beverage containers and could get their money back on returning them.
D. Beverage companies should be responsible for collecting and reusing discarded plastic soda bottles.
【单选题】
The returned plastic bottles in New York used to _____________.___
A. be turned into raw materials
B. be separated from other rubbish
C. have a second-life value
D. end up somewhere underground
【单选题】
The key problem in dealing with returned plastic beverage containers is ______________.___
A. how to reduce their recycling costs
B. to sell them at a profitable price
C. how to turn them into useful things
D. to lower the prices for used materials
【单选题】
Recycling has become the first choice for the disposal of rubbish because ______________.___
A. recycling causes little pollution
B. other methods are more expensive
C. recycling has great appeal for the jobless
D. local governments find it easy to manage
【单选题】
It can be concluded from the passage that ____________.___
A. recycling is to be recommended both economically and environmentally
B. local governments in the U.S. can expect big profits from recycling
C. rubbish is a potential remedy for the shortage of raw materials
D. landfills will still be widely used for waste disposal
【单选题】
The author chose to study engineering at a small liberal-arts university because he ________.___
A. intended to be a sensible student with noble ideals
B. wanted to be an example of practicality and rationality
C. intended to be a combination of engineer and humanist
D. wanted to coordinate engineering with liberal-arts courses in college
【单选题】
According to the author, by interacting with people who study liberal arts, engineering students can __________.___
A. broaden their horizons
B. receive guidance in their careers
C. become noble idealists
D. balance engineering and the liberal arts
【单选题】
In the eyes of the author, a successful engineering student is expected ______________.___
A. to be imaginative with a value system to guide him
B. to be a technical genius with a wide vision
C. to have an excellent academic record
D. to be wise and mature
【单选题】
The author's experience shows that he was ________.___
A. creative
B. ambitious
C. irrational
D. unrealistic
【单选题】
The underlined word "they" in "... together they threaten to confuse." (Para.5) refers to ____________.___
A. practicality and rationality
B. engineering and the liberal arts
C. reality and noble ideals
D. flexibility and a value system
【单选题】
It can be learned from the passage that the Ouchidas' house __________.___
A. failed to meet energy conservation standards
B. was designed and constructed in a scientific way
C. is well worth the money spent on its construction
D. is almost faultless from the point of energy conservation
【单选题】
What made the Ouchidas' new house a horrible dream?___
A. Lack of fresh air.
B. Gas leakage in the kitchen.
C. The newly painted walls.
D. Poor quality of building materials.
【单选题】
The underlined word "accentuate" (Para. 3) most probably means "________".___
A. worsen
B. accelerate
C. relieve
D. improve
【单选题】
Why were cracks in old houses not a big concern?___
A. Because environmental protection was given top priority.
B. Because indoor cleanness was not emphasized.
C. Because they were technically unavoidable.
D. Because energy used to be inexpensive.
【单选题】
This passage is most probably taken from an article entitled "_________".___
A. Energy Conservation
B. Air Pollution Indoors
C. House Building Crisis
D. Traps in Building Construction
【单选题】
We need to plan ahead in order to ___________.___
A. keep a record of all the events
B. better organize our activities
C. store everything in our head
D. pile up little tasks neatly
【单选题】
Strategic times are best for us to ___________.___
A. save energy
B. check e-mails
C. study efficiently
D. organize activities
【单选题】
Which of the following could be used as a motivation to do our assignments?___
A. Remembering our urgent tasks.
B. Any activities we're eager to do.
C. Taking a break in the afternoon.
D. The promise to study efficiently.
【单选题】
What can help us to keep refreshed throughout the day?___
A. Doing some physical exercise.
B. Taking a short nap in the afternoon.
C. Rushing through some assignments.
D. Playing a game of chess with a friend.
【单选题】
Which of the following could be the best title for this article?___
A. Study Habits and Time Management
B. Business Management and Leadership
C. University Education and Campus Life
D. Life Goals and Academic Development
【单选题】
It is implied in the text that it is hard to ________.___
A. carry life learning though
B. tell the nature of life learning
C. learn without going to school
D. find a specially trained teacher
【单选题】
According to the author, the schooling framework often ________.___
A. produces slow students with poor memories
B. ignores some parts of the official curriculum
C. fails to provide enough knowledge about life
D. gives little care to the quality of teaching materials
【单选题】
Life learners recognize that learning will not be difficult if they are _________.___
A. clear about why to learn
B. careful to make a time table
C. able to respect other people
D. cautious about any mistakes
【单选题】
According to the author, life learning ________.___
A. could prevent one from running risks
B. could be a road full of trials and errors
C. makes a kid independent of his parents
D. teaches a kid how to avoid being scorned
【单选题】
Through life learning, children ________.___
A. will grow without the assistance from parents
B. will learn to communicate with the real world
C. will be driven to learn necessary life knowledge
D. will be isolated from the negative side of society
【单选题】
A good title for this passage is __________.___
A. Sleep
B. Good Health
C. Dreams
D. Work and Rest
【单选题】
The word drowsy in the last paragraph means __________.___
A. sick
B. stand up
C. asleep
D. a little sleepy
【单选题】
This passage suggests that not getting enough sleep might make you ___________.___
A. dream more often
B. have poor health
C. nervous
D. breathe quickly
【单选题】
During REM, ___________ .___
A. your eyes move quickly
B. you dream
C. you are restless
D. both A and B
【单选题】
The average number of hours of sleep that an adult needs is __________.___
A. approximately six hours
B. around ten hours
C. about eight hours
D. not stated here
