【单选题】
KP—2B控制箱的主要控制元件是_____.___
A. 晶闸管
B. 电容
C. 三极管
D. 电阻
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相关试题
【单选题】
TKZW_1T型轴报器的定点报警温度为_____度___
A. 85+-1
B. 90+-1
C. 95+-1
D. 96+-1
【单选题】
保险丝的额定电流是指容许通过的________
A. 额定电流
B. 工作电流
C. 最大电流值
D. 最小电流值
【单选题】
_____V以下的电压为安全电压.___
【单选题】
BY_2型逆变器的工作电压为直流_____V___
A. 25-30
B. 30-35
C. 36-40
D. 44-65
【单选题】
车辆正常运行时,KP-2A型供电装置电池电流正常值是________
【单选题】
J5型发电机的额定功率为_____W___
【单选题】
电风扇段修后,温升试验时其测量绝缘电阻不得小于_____MG___
A. 0.2
B. 0.5
C. 1
D. 1.5
【单选题】
低压电器一般是指工作在交流_____V以下电路的电器.___
A. 400
B. 380
C. 220
D. 1000
【单选题】
下列属于低压控制电器的是________
A. 熔断器
B. 刀开关
C. 自动开关
D. 接触器
【单选题】
下列属于低压配电电器的是________
A. 手控开关
B. 自动开关
C. 主电器
D. 继电器
【单选题】
利用熔体熔化作用而切断电路的保护电器叫________
A. 自动开关
B. 组合开关
C. 闸刀开关
D. 熔断器
【单选题】
段修后,蓄电池容量应为额定容量的_____以上.222110216]___
A. 60%
B. 70%
C. 80%
D. 90%
【单选题】
客车车体配线段修后,墙板引出线的支线截换时须留有_____MM以上的余量.___
A. 80
B. 100
C. 150
D. 200
【单选题】
单元式空调装置的制冷系统由压缩机,冷凝器节流装置和_____等组成。___
A. 蒸发器
B. 毛细管
C. 截止阀
D. 汽液分离器
【单选题】
电感器在电路中可以通过________
A. 交流电
B. 直流电
C. 交流电和直流电
D. 高压电
【单选题】
电茶炉产水量下降的原因是________
A. 电热管烧损
B. 与电热管无关
C. 电热开关损坏
D. 无电源输入
【单选题】
客车空调装置的控制线路中设有欠压保护器,当供电电压低于额定电压的_____时,自动切断电源,停止运行,保护电机。___
A. 5%~8%
B. 10%~15%
C. 18%~20%
D. 20%~25%
【单选题】
蓄电池充电时,电解液温度不超过_____摄氏度。___
【单选题】
电气装置与轨面距离运用限度规定不小于_____mm。___
A. 80
B. 100
C. 120
D. 150
【单选题】
用万用表测得二极管正、反向电阻都为无穷大,表明该二极管_____。___
A. 短路
B. 断路
C. 性能不好
D. 正常
【单选题】
根据压缩机的工作原理,压缩机可分为_____型和速度型两种。___
【单选题】
冷凝压力过高会导致压缩机超载运行,容易损坏_____。322110305]___
A. 压缩机零件
B. 冷凝器
C. 蒸发器
D. 节流装置
【单选题】
当供电电压低于额定电压的10%~15%时,_____保护器就切断电源。___
【单选题】
制冷空调是利用容易_____的液体——低压制冷剂,在蒸发和冷凝时的吸热和放热来达到制冷的目的。___
【单选题】
交流接触器短路环的作用是_____。___
A. 励磁
B. 增加电磁吸力
C. 节电运行
D. 消除振动和噪声
【单选题】
调整和检查自动空气开关和主接触器的触头,应注意触头的_____。___
A. 开距、压力
B. 压力、超程
C. 压力、开距、超程
D. 开距、超程
【单选题】
同一组蓄电池中各个蓄电池的容量互差不得超过_____。___
A. 5%
B. 10%
C. 15%
D. 20%
【单选题】
我国客车空调制冷装置采用的制冷剂主要是_____。___
【单选题】
KT01客车按键式轴温报警器,若显示屏显示“NE-0”或“NE-1”分别表示第N号轴数的温度传感器出现_____状态。___
A. 正常和开路
B. 正常和短路
C. 短路和开路
D. 开路和短路
【单选题】
空调装置无冷气或冷气不足,这是与制冷系统有关的问题,应检查_____系统。___
【单选题】
通风机转动的方向正确与否,可以从_____大小来判断。___
【单选题】
一个空调系统的新风量Gw不应小于总送风量的_____。___
【单选题】
全部采用空气调节的旅客列车应用_____供电方式是比较合理的。___
【单选题】
测直流电时,电压表的正端应接被测电路的_____。___
A. 高电位端
B. 正极
C. 负极
D. 低电位端
【单选题】
测直流电流时,应注意电路电流的_____。___
【单选题】
使用兆欧表时,摇动手柄的速度应掌握在_____r/s左右。___
【单选题】
厂修客车车上干线过梁部分,茶炉室、锅炉室、厨房、水箱附近电线,车上支线及自车下钢管引出的电线均须套_____。___
A. 塑料管
B. 橡胶管
C. 帆布管
D. 任意
【单选题】
我国客车车下布线主干线、支线连接均应采用分线盒内_____联接型式。___
A. 单线制
B. 双线制
C. 单、双线混合制
D. 视具体车型而定
【单选题】
TKZW-1T型轴报器的定点报警温度为_____℃。___
A. 85±5
B. 90±2
C. 95±5
D. 100±5
【单选题】
轴温报警器的报警温度,夏季应为_____℃。___
推荐试题
【单选题】
Q2: What is the actual reason that Katy doesn’t want to attend Jason’s party?___
A. None of her friends likes Jason .
B. None of Jason's guests is young .
C. She wants to go to Linda's party ..
D. She went to Jason's party last year .
【单选题】
Q3: What is special about Linda’s party?___
A. The party will last four hours .
B. Six people will attend the party .
C. They will have huge bags of candy .
D. They will play a new game called "GuessWho ".
【单选题】
Q4: What will Katy do to solve her problem?___
A. Go to Jason's party .
B. Go to Linda's party .
C. Attend both Jason's and Linda's parties .
D. Celebrate Halloween with her parents .
【单选题】
Q1: What is special about this year’s Black Friday shopping?___
A. Some stores offered bigger holiday discounts .
B. Some stores provided more choices of nightlife.
C. Some stores made efforts to attract young people .
D. Some stores opened much earlier than they used to .
【单选题】
Q2: Why did some stores open at midnight on Thanksgiving night?___
A. To attract young customers .
B. To beat other stores for sale.
C. To let people sleep late the next day .
D. To keep people stay up for the night .
【单选题】
Q3: How many Black Friday shoppers were reported to go to the shops at midnight this year?___
A. 24 percent .
B. 37 percent .
C. 9.5 percent .
D. 23.5 percent .
【单选题】
Q4: What can we learn about the 15-year-old Jenny?___
A. She and her cousins went back home at midnight .
B. She liked the traditional 4 a.m. Black Friday.
C. She preferred midnight shopping to early morning shopping .
D. She and her cousins got up very early to buy discounted items .
【单选题】
Q1: Why did the woman decide to do a triathlon?___
A. Because she did it in college .
B. Because she wanted to be tough .
C. Because her sister did it and liked it .
D. Because her sister said it was good for her .
【单选题】
Q2: When did the man first do a triathlon?___
A. Last year .
B. In college .
C. Last week .
D. In high school .
【单选题】
Q3: How does the man feel about running?___
A. Boring.
B. Scaring .
C. Exciting .
D. Interesting .
【单选题】
Q4: Why doesn’t the woman like swimming in the triathlon?___
A. Because she fears that a big fish might eat her .
B. Because she fears that she would get lost in lakes .
C. Because she doesn't want to scare away small fishes .
D. Because she doesn't like swimming with many people .
【单选题】
Q1: What is the ratio of positive to negative emotions that can make a person happier?___
A. 1:3.
B. 3 :1.
C. 1 :10 .
D. 10 :1.
【单选题】
Q2: What is the most exciting finding about increasing positive emotions?___
A. It improves relationships .
B. It leads to greater success .
C. It helps develop creativity .
D. It contributes to good health .
【单选题】
Q3: What does the speaker say about negative feelings?___
A. People should turn every negative feeling around .
B. Negative feelings can sometimes have positive effects .
C. Negative feelings often cause people to make mistakes .
D. People should never show negative feelings in public places .
【单选题】
Q4: What is the main idea of the passage?___
A. People should learn to manage their emotions .
B. People should be patient with their negative feelings .
C. People should learn to analyze causes of unhappiness .
D. People should identify as many positive feelings as possible .
【单选题】
Q1: What are the man and woman talking about?___
A. Whether nature is magical and kind .
B. Whether nature is powerful and full of risks .
C. Whether Christopher was well prepared for the trip .
D. Whether Christopher's trip to Alaska was worthwhile .
【单选题】
Q2: What can we learn about Christopher?___
A. He made a film about his trip to Alaska .
B. He wrote a story about his trip to Alaska .
C. He died while having an adventure in Alaska .
D. He learned how powerful and risky Alaska was .
【单选题】
Q3: What does the woman think about Christopher taking the trip to Alaska?___
A. He was too foolish .
B. He was really romantic .
C. He had a very kind heart .
D. He had a spirit for trying things .
【单选题】
Q4: Which of the following is NOT mentioned as something that would have saved Christopher’s life?___
A. A gun to hunt .
B. The map of the area .
C. Emergency food supplies .
D.
E. mergency communication equipment .
【单选题】
Q1: What speed can an avalanche reach within five seconds of taking off?___
A. At 8 miles an hour .
B. At 18 miles an hour .
C. At 80 miles an hour .
D. At 88 miles an hour .
【单选题】
Q2: According to the passage, under what circumstances may an avalanche occur?___
A. There are too many layers of snow on the .
B. There is a layer of snow covering an entire area .
C. The top layer of snow slides off the layer below it .
D. The layer of snow below the surface becomes unstable .
【单选题】
Q3: What are skiers advised to do to avoid being caught in an avalanche?___
A. Ski only in the official ski areas .
B. Look for solid snow to walk on .
C. Look out for each other while skiing .
D. Learn to control themselves in an avalanche .
【单选题】
Q4: Why does the ski patrol use explosives?___
A. To dig holes in the snow .
B. To close the area for skiing .
C. To make an avalanche move on purpose .
D. To' check how different layers are holding up .
【单选题】
Q1:What is conversation mainly about?___
A. The woman's happy college life the man's doubt .
B. The woman's spending habits and the man's concerns .
C. The man's reminding the woman of the exam this Thursday .
D. The man's support for the woman over the past 15 years .
【单选题】
Q2:What did the woman do last night?___
A. She bought a new leather coat .
B. She studied very hard for an exam .
C. She treated all her friends to dinner .
D. She went to a concert with her friends .
【单选题】
Q3:Where did the woman get the money?___
A. She just received her student loan .
B. She saved some money for herself .
C. She borrowed the money from her friends .
D. She asked her mom to send her the money .
【单选题】
Q4:What is the man?___
A. A teacher of biology .
B. An undergraduate student .
C. A freshman in biology class .
D. A graduate teaching assistant .
【单选题】
Q1: What is this passage mainly about?___
A. How businesses can compete with each other .
B. How small businesses operate during holidays .
C. How small businesses manage holiday workers .
D. How can earn more money during holidays .
【单选题】
Q2: According to Rubin, what can small companies do to thank holiday workers?___
A. Have talks with their families .
B. Give them good extra benefits .
C. Offer them expensive holiday tokens .
D. Show appreciation to them face to face .
【单选题】
Q3: What can small business owners do to help holiday workers get into the holiday spirit?___
A. Entertain them with big meals .
B. Let them enjoy some holiday games .
C. Give them handmade thank-you cards .
D. Send their families some holiday gift cards .
【单选题】
Q4: Who are supposed to benefit most from this passage?___
A. Workers who have to work during holidays .
B. Employees who intend to earn extra money .
C. Big companies that usually close on holidays .
D. Small businesses that try to be more competitive .
【单选题】
In the first two paragraphs of the passage the writer tries to tell us that___
A. he had lived in Washington D.C. for twenty years
B. he was very imaginative when he was a child
C. he had fond memories of his old neighborhood
D. )he had come from a very poor neighborhood
【单选题】
The writer ,as a child ,was very fond of playing in the basement because ___
A. it was bright and alive
B. it contained a movie house and a space station
C. it was ideal for playing hide-and-seek
D. it was surrounded by trees and flowers
【单选题】
How did the writer feel when he visited his old neighborhood in Washington D.C. ?___
A. Greatly surprised .
B. Very regretful .
C. Quite excited .
D. Very sad .
【单选题】
On his visit to his hometown ,the writer found the old apartment building___
A. see medunfit to live in
B. had been repaired
C. could hardly be recognized
D. looked dirty and smelt horrible
【单选题】
" Youcan never go home again "inthe last sentence of this passage means that___
A. one should never revisit his hometown after many years of absence
B. one will never find his hometown the same as it was in his childhood memory
C. avisit to one's hometown will bring back one's fond memories of home
D. avisit to one's hometown will bring back many sad memorie
【单选题】
We learn from the passage that Tracy died___
A. on December 8,1992
B. of brain damage
C. 24 hours after he fell off the roof of a car
D. in a car crash
【单选题】
Tracy's parents decided to donate Tracy's organs because___
A. Tracy told them to do so just before he died
B. they wanted to save others the pain of seeing a dear one die
C. David's life could continue in a meaningful way
D. they knew David was suffering from a hopeless liver disease
【单选题】
The meeting between the writer's family and Tracy's parents was arranged because___
A. the writer and her husband wished to express their thanks to Tracy's parents
B. the local organ bank wanted to see how both families felt about the donation
C. Tracy's parents wanted to see someone whose life had been saved by the donation
D. the two families were linked by the most bittersweet ties imaginable
【单选题】
The writer and her husband learned how Tracy died___
A. from his parents
B. from the organ bank
C. from the hospital
D. from the doctor who performed the operation