【单选题】
在区间或站场线路上,为满足( )方面的要求,将接触网分成若干段,每段长度为1500~2000m,且相互独立。___
A. 供电
B. 机械
C. 供电和机械
D. 检修
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相关试题
【单选题】
绝缘锚段关节配合隔离开关的使用,可以( )。___
A. 缩小停电检修范围
B. 扩大停电检修范围
C. 改变导线高度
D. 调整张力与弛度
【单选题】
非绝缘锚段关节( )作用,它通过两根锚柱和两根转换柱来实现锚段的衔接和过渡。___
A. 只起衔接
B. 只起过渡
C. 不进行机械的分段,只起电的分段
D. 不进行电的分段,只起机械分段
【单选题】
非绝缘锚段关节它通过两根锚柱和两根转换柱来实现锚段的( )。___
A. 衔接
B. 过渡
C. 衔接和过渡
D. 连接
【单选题】
供电距离越长,牵引电流在( )上的电压降越大,使末端电压过低及接触网上电能损耗过大。___
A. 接触线
B. 接触网
C. 变电站
D. 变电网
【单选题】
补偿器的 、 值主要受( )的变化而变化,接触线和承力索补偿器的 、 值( )。___
A. 环境 不相等
B. 环境 相等
C. 温度 不相等
D. 温度 相等
【单选题】
曲线区段上随曲线半径不同拉出值有差异,一般在( )之间。___
A. 150-300mm
B. 150-400mm
C. 150-500mm
D. 150-600mm
【单选题】
接触线是直接和受电弓滑板相接触并摩擦的,电动列车从( )上取得电能。___
A. 吊索
B. 吊弦
C. 承力索
D. 接触线
【单选题】
那种绝缘子性能反映了防雷需求的电气性能指标。___
A. 干闪络电压
B. 湿闪络电压
C. 击穿电压
D. 工作电压
【单选题】
击穿电压至少应比干闪电压高( )倍。___
【单选题】
绝缘子除起电气性能外,还承受一定的机械负荷。因此,要求绝缘子有一定的安全系数,一般绝缘子安全系数规定为( )。___
A. 1~5
B. 2~5
C. 5~3
D. 3~5
【单选题】
绝缘子要求质地紧密均匀,任何一个断面上不能有裂纹和气孔,表面( )后可防止水分的渗入。___
A. 冷处理
B. 热处理
C. 剖光
D. 涂釉
【单选题】
新购、制作(或大修)后,接触网检修工具在第一次投入使用前进行( )和电气强度试验。___
【单选题】
棒式绝缘子用在( )上、隧道内悬挂和隧道内定位等处。___
A. 承受拉力
B. 承受扭矩
C. 承受悬挂
D. 绝缘腕臂
【单选题】
液压压接钳一般为专用型和较大尺寸的压接,( )KN。机械压接钳为小尺寸的压接,69KN。___
A. 300
B. 180
C. 200
D. 110
【单选题】
螺纹联接拧紧对于受拉螺栓连接,可提高螺栓的()。___
A. 刚性
B. 紧密性
C. 防松
D. 疲劳强度
【单选题】
三角形螺纹的牙形为( ),当量摩擦系数大,自锁性好,主要用于联接。___
A. 30°
B. 45°
C. 55°
D. 60°
【单选题】
圆锥螺纹不用填料而靠牙的( )来保证螺纹副的紧密性。___
【单选题】
螺纹联接是利用( )构成的可拆联接。___
A. 螺纹零件
B. 摩擦零件
C. 机械零件
D. 零件间隙
【单选题】
温度变化时,线索受温度影响而伸长或缩短,由于()坠砣的重量作用,可使线索沿线路方向移动而自动调整线索张力,使张力恒定不变,并借以保持线的驰度满足技术要求。___
A. 补偿器
B. 控制器
C. 断路器
D. 短路器
【单选题】
接触线在夏季随着温度升高触线长度( )___
【单选题】
下锚补偿装置检查时注意大、小轮补偿绳是否有磨擦棘轮现象,小轮补偿绳张力是否一致,平衡轮是否处于( )平衡状态___
A. 垂直
B. 水平
C. 30°倾斜
D. 拉力
【单选题】
中国大陆称接触网供电或架空接触网,台湾称高架电缆或架空电缆,是( )铁路常用的两种供电网络方式之一。___
【单选题】
在铁路和城市轨道交通系统中,架空接触网只有导线的一个电极,电力机车通过集电装置取电,再通过()回流到电网中。___
A. 电缆线
B. 变频器
C. 金属轮轨
D. 人工方式
【单选题】
用验电器验电的顺序是:将验电器上端挂在接触线(汇流排)上,验电器表计端头靠到钢轨上,指示灯不亮,读数表为( ),为已停电。 ___
A. 0
B. ∞
C. 100V
D. 1000V
【单选题】
验电器使用前需要到( )带电设备试验,确认验电器功能完好。___
A. 交流
B. 直流
C. 高压
D. 同电压等级
【单选题】
吊弦的长度要能适应在极限温度范围内接触线的()的变化。___
A. 伸缩
B. 弛度
C. 伸缩和弛度
D. 导线高度
【单选题】
吊弦喜爱垂直线路方向的偏移角不得大于( )。___
A. 10°
B. 15°
C. 20°
D. 25°
【单选题】
要求承力索能够承受较大的( )和具有抗腐蚀能力,并且在温度变化时驰度变化较小。___
【单选题】
铜( )导电性能好,可做牵引电流的通道之一,和接触网并联供电,降低压损和能耗,且抗腐蚀性能提高。___
A. 吊索
B. 吊弦
C. 承力索
D. 接触线
【单选题】
承力索的主要作用是通过吊弦将接触线悬吊起来,提高悬挂的稳定性,与接触线( )供电。___
【单选题】
TJR120表示( )。___
A. 截面积为120mm2的软铜绞线
B. 截面积为120mm2的硬铜绞线
C. 截面积为120m2的软铜绞线
D. 截面积为150m2的软铜绞线
【单选题】
。用聚酯丙烯纤维制成的各类合成纤维绳用于合成树脂腕臂的紧固、滑轮悬挂和软横跨。这些绳索起到()。___
A. 机械作用
B. 绝缘作用
C. 机械和绝缘的作用
D. 非绝缘作用
【单选题】
由于交流电通过导体时会发生集肤效应,其( )电阻不是均匀分布的。___
【单选题】
线索在温度升高或降低时发生变形的常量,即单位长度的金属线索在( )变化摄氏一度时的伸缩量。___
【单选题】
表示线索性能的综合拉断力是金属材料在拉伸(或压缩),剪切,弯曲等各种外力作用下,发生断裂时的外力( )。___
【单选题】
表示线索性能的综合拉断力的单位是( )。___
A. N
B. 10N
C. 100N
D. KN
【单选题】
线索性能的抗拉强度表示金属材料抵抗( )变形的能力,单位Pa。___
【单选题】
抗拉强度有材料单位面积上能承受( )的大小来决定。___
【单选题】
银含量( )或镁含量(0.5%)的合金添加剂用来进一步改善铜线的机械和热性能,从而得以使用较高张力的铜线。___
A. 0.001
B. 0.002
C. 0.003
D. 0.004
推荐试题
【单选题】
Tom is a book lover. ______ likes reading very much.
A. He B. She C. You D. It
【单选题】
—May I listen to the music here, Mr. White?
—Sorry, you’d better it like that.
A. not to do B. not do to
C. dont do D. not do
【单选题】
3.—Did you have a good time at Lauras birthday party?
— Yes, indeed. Its several years ________ I enjoyed myself so much.
A. when B. before C. since D. that
【单选题】
4. —___________ is the Summer Palace from here?
About three kilometers away. You can take the No. 35 bus.
A. How long B. How far C. How often D. How much
【单选题】
5. I was looking for a birthday gift for my mother, but I couldnt find ______ suitable.
A. anything B. something C. nothing D. everything
【单选题】
6. A friend of my ____ and I are going to visit_______ next week.
A. father; Browns B. father's; Browns
C. father; the Browns D. father's; the Browns
【单选题】
7. She ______ very hard since she came to our school.
A. studies B. has studied C. is studying D. studied
【单选题】
8. — Who will send you to the new school, your mom or your dad?
— _______. Ill go there by myself.
A. Both B. Either C. Neither D. None
【单选题】
9.—Well do what we can ____English well this term.
—It’s high time for you to work hard.
A. study B.to study C. be studied D. be studying
【单选题】
10. —I’m going to Flower Bookstore. Could you tell me ______?
— Sorry, I don’t know. I’m new here.
A. where it is B. where was it C. where is it D. where it was
【单选题】
11. How do you like the dishes, Eric?
— Fantastic! Nothing tastes ________.
A. nice B. better C. terrible D. worse
【单选题】
12. ______ Lin Feng has to work late, she always wears a smile on her face.
A. Because B. If C. Until D. Though
【单选题】
13.You can save money _______ you buy cheaper things.
A. before B. unless C. if D. until
【单选题】
14. We will have a _________ holiday after the exam.
A. two-month B. two month’s C. two month D. two-months
【单选题】
15. —We will build an underground in Xuzhou before 2015.
— Wow, _______! Will it pass our place?
A. what an excited news B. how excited the news is
C. what exciting news D. how exciting
【单选题】
16. — Emily, here’s a dictionary.I hope it will help you in some way.
— Thank you.It’s ________ what I need.
A. almost B. still C. only D. just
【单选题】
17. —Oh.I’m hungry.Mum, can I have the hamburger on the plate?
—No.It tastes .
A. terribly B. terrible C. good D. well
【单选题】
18. —We can invite our teachers to the farewell party next Saturday.
—Yes, ______? I’ll call them at once.
A. what for B. what C. why not D. why
【单选题】
19.You can ________ ask the old man to move away to any other place because he has lived ________ here for at least sixty years.
A. hardly; alone B. hard; alone
C. hardly; lonely D. hardly; lonely
【单选题】
20.—I’m going back to see my grandparents this weekend.
—________.
A. It’s very nice of you B. You’d better hurry
C. Say goodbye to them D. Give my best wishes to them
【单选题】
21.—Why not take ____ umbrella with the sign “Made in China”? It is useful.
—What _______ good advice it is!
A. an; a B. a; a C. an; \ D. \; a
【单选题】
22. —Do you know the boy________ is sitting next to Peter?
— Yes. He is Peter’s friend. They are celebrating his ________ birthday.
A. who; ninth B. that; ninth C. /; ninth D. which; ninth
【单选题】
23. It was dark, ______ I couldnt see what was happening.
A. or B. though C. but D. so
【单选题】
24.—You can use MSN to talk with Vivien on the Internet.
—I know. But can you tell me ________?
A. what I can use it B. when I can use it
C. why can I use it D. how can I use it
【单选题】
25. _______ are you going to the School Uniform Exhibition, Amy ?
To learn about different styles of school uniform.
A. What B. Where C. Which D. Why
【单选题】
( ) 26. Where does the writer of "The little Prince" come from?
A.England. B.France. C.America. D.China.
【单选题】
( ) 27. What does the prince do after the fox tells him a secret?
A.He cares more about a flower and a sheep.
B.He meets many more strange adults on other planets.
C.He realizes his love for the rose and he goes back to his planet.
D.He discovers interesting things such as a snake, other roses and a fox
【单选题】
( ) 28. What does "The little Prince" mainly talk about? It' s about _________.
A.the adult world B.the planet B -612
C.a rose and a fox D.the adventure of a young prince
【单选题】
( ) 29. What is the writer's main purpose(目的)in writing this passage?
A.To tell the readers his life story.
B.To tell people what kind of person his father was.
C.To tell the readers what present he got from his father.
D. To let people know how poor he was.
【单选题】
( ) 30. Why did the father not ask his son not to do this and do that?
A.Because he felt quite confident of his son.
B.Because he was born from a poor family.
C.Because he was a man of few words.
D.Because he didn't want to be much too strict with his son.
【单选题】
( ) 31. What would someone learn from this passage?
A.How to live by oneself. B.How to stand on one's own feet.
C.What a good father should do. D.What the self-important is like.
【单选题】
( ) 32. What may be the proper Chinese for the underlined part in the passage?
A.闲暇时光 B.学费 C.精神空虚 D.经济不足
【单选题】
( ) 33. Why did Natalie Smith pay for the six cars behind her?
A. She had seven tickets.
B. She hoped to please others.
C. She knew the car drivers well.
D. She wanted to show kindness.
【单选题】
( ) 34. Judy Foreman copied down the phrase because she ___ .
A. thought it was beautifully written
B. wanted to know what it really meant
C. decided to write it on a warehouse wall
D. wanted her husband to put it up in the classroom
【单选题】
( ) 35. Who came up with the phrase according to the passage?
A. Judy Foreman. B. Natalie Smith. C. Anne Herbert D. Alice Johnson.
【单选题】
( ) 36. What can we infer from the last paragraph?
A. People should practice random kindness to those in need.
B. People who receive kindness are likely to offer it to others.
C. People should practice random kindness to strangers they meet.
D. People who receive kindness are likely to pay it back to the giver.
【单选题】
( ) 37.The greatest river for navigation is ___________.
A. the Nile B. the Amazon C. the Mekong D. the Mississippi
【单选题】
( ) 38. From a dam, people can use the water for ___________.
A. keeping the rivers clean B. only making electricity
C. irrigation and making electricity D. washing clothes
【单选题】
( ) 39. The water in the river is polluted because of _____________.
A. people's drinking water too much B. people's swimming in the river too much
C. chemicals and other materials D. people's building a dam across a river
【单选题】
( ) 40. The best title of the passage is ___________.
A. Rivers in Cities B. The importance of Rivers
C. Transportation D. Natural Resources