【单选题】
云中的水滴受强烈气流的摩擦产生电荷,而且小水滴带___。
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相关试题
【单选题】
变压器保护属于按___分类。
A. 被保护的对象
B. 保护原理
C. 保护所起作用
【单选题】
真空断路器要求波纹管既能保证动触头能做___,同时又不能破坏灭弧室的真空度。
【单选题】
电流对人体的伤害可以分为___两种类型。
A. 电伤、电击
B. 触电、电击
C. 电伤、电烙印
【单选题】
电力线路按架设方式可分为___。
A. 输电线路和配电线路
B. 高压线路和低压线路
C. 架空电力线路和电力电缆线路
【单选题】
下列___不属于电力系统中的事故。
A. 对用户少送电
B. 电能质量降低到不能允许的程度
C. 过负荷
【单选题】
下列___表示110KV母线电流差动保护A相电流公共回路。
【单选题】
电气设备有三种工作状态,即运行、___、检修状态。
【单选题】
通常要求真空断路器的触头材料具有的性能之一是___。
A. 耐弧性强
B. 导热性能差
C. 绝缘性能强
【单选题】
检修状态指设备的___,而且接地线等安全措施均已做好,这时设备就处在检修状态。
A. 开关已拉开
B. 操作电源已断开
C. 开关和刀闸均已拉开
【单选题】
在110kV及以上的电力系统,一般采用中性点直接接地的运行方式,以___。
A. 降低设备的绝缘水平
B. 保障人身安全
C. 保障人身设备安全
【单选题】
真空断路器是利用___作绝缘介质和灭弧介质的断路器。
【单选题】
流过导体单位截面积的电流叫电流密度,其单位为___。
A. 安培
B. 安培/平方米
C. 安培/平方毫米
【单选题】
继电保护回路编号用___位及以下的数字组成。
【单选题】
人体与带电体直接接触触电,以___对人体的危险性最大。
A. 中性点直接接地系统的单相触电
B. 两相触电
C. 中性点不直接接地系统的单相触电
【单选题】
屋顶上单支避雷针的保护范围可按保护角___确定。
【单选题】
变压器的一、二次电压一般允许有___的差值,超过则可能在两台变压器绕组中产生环流,影响出力,甚至可能烧坏变压器。
【单选题】
下列___属于辅助安全用具。
A. 绝缘手套、绝缘靴
B. 绝缘棒、绝缘夹钳
C. 携带型接地线、临时遮栏
【单选题】
在办理停电、送电手续时,严禁___停电、送电。
【单选题】
运行中的断路器日常维护工作包括对___的定期清扫。
A. 二次控制回路
B. 绝缘部分
C. 不带电部分
【单选题】
隔离开关按刀闸运动方式分类可分为___、垂直旋转式和插入式。
A. 360°旋转式
B. 捆绑式
C. 水平旋转式
【单选题】
架空线路装设自动重合闸装置后,可以___。
A. 提高耐雷水平
B. 提高供电可靠性
C. 降低杆塔接地电阻
【单选题】
当变压器容量由冷却方式而变更时,则额定容量是指___。
A. 最大的容量
B. 最小的容量
C. 中间的容量
【单选题】
手车式开关柜,小车已拉出,开关断开,于本室内接地刀闸已闭合,称之为___状态。
【单选题】
当电气装置或设备发生火灾或引燃附近可燃物时,首先要___。
【单选题】
用万用表测量电阻时,则需要将___作为测量电源。
【单选题】
为了适应断路器在不同安装地点的耐压需要,国家相关标准中规定了断路器可承受的___。
A. 最高工作电压
B. 最低工作电压
C. 最小过电压幅值
【单选题】
三相变压器绕组为D联结时,___。
A. 线电流为√3倍的绕组电流
B. 线电流为绕组电流
C. 线电流为2倍的绕组电流
【单选题】
在不损害变压器___和降低变压器使用寿命的前提下,变压器在较短时间内所能输出的最大容量为变压器的过负载能力。
【单选题】
三相变压器Dyn11绕组接线表示一次绕组接成___。
【单选题】
继电保护的___是指发生了属于它该动作的故障,它能可靠动作而在不该动作时,它能可靠不动。
【单选题】
在全部停电和部分停电的电气设备上工作,必须完成的技术措施有___。
A. 停电;验电;挂接地线;装设遮栏和悬挂标示牌
B. 停电;放电;挂接地线;装设遮栏和悬挂标示牌
C. 停电;验电;放电;装设遮栏和悬挂标示牌
【单选题】
电气设备相位漆标识的黄、绿、红颜色分别代表___相位。
【单选题】
绝缘手套属于___。
A. 绝缘安全用具
B. 一般防护安全用具
C. 辅助安全用具
【单选题】
电力变压器按冷却介质可分为___和干式两种。
【单选题】
___所发信号不应随电气量的消失而消失,要有机械或电气自保持。
A. 时间继电器
B. 中间继电器
C. 信号继电器
【单选题】
工作接地的接地电阻一般不应超过___Ω。
【单选题】
电力电缆中,线芯(导体)是用来___,是电缆的主要部分。
A. 输送电能
B. 使导线与外面绝缘
C. 输送电压
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It is our___policy that we will achieve unity through peaceful means.
A. consistent
B. continuous
C. considerate
D. continual
【单选题】
The author of the report is well___with the problems in the hospital because he has been working there for many years.
A. informed
B. acquainted
C. enlightened
D. acknowledged
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The manager lost his ___ just because his secretary was ten minutes late.
A. mood
B. temper
C. mind
D. passion
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Many Europeans___ the continent of Africa in the 19th century.
A. exploded
B. explored
C. exposed
D. expanded
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If you hear such a rumor,___ it thoroughly.
A. seek
B. investigate
C. search
D. explore
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The pressure ___causes Americans to be energetic, but it also puts them under a constant emotional strain.
A. to compete
B. competing
C. to be competed
D. having competed
【单选题】
Having decided to rent a flat, we ___ contacting all the accommodation agencies in the city.
A. set about
B. set on
C. set out
D. set up
【单选题】
The old couple decided to ___ a boy and a girl though they had three children of their own.
A. adapt
B. adjust
C. adept
D. adopt
【单选题】
Mike was being ___for violent tendencies.
A. contended
B. consulted
C. counselled
D. insulted
【单选题】
I will___ Mr. Walters on this point.
A. refer to
B. commit to
C. contribute to
D. defer to
【单选题】
What happens in the next few days is___to our success.
A. critical
B. critic
C. prior
D. valid
【单选题】
She won’t___that there is a problem.
A. confer
B. concern
C. acknowledge
D. contemplate
【单选题】
This offer is___ for travel before the end of April.
A. effective
B. ineffective
C. invalid
D. valid
【单选题】
___ to British universities depends on examination results.
A. Admittance
B. Entry
C. Admission
D.
E. ntrance
【单选题】
The database is only ___ by authorized managers.
A. proved
B. accessible
C. approved
D. access
【单选题】
This traditional ___ is of indigo blue.
A. clothes
B. diversity
C. costume
D. institution
【单选题】
These cigarettes are a ___ of the best tobaccos.
A. blend
B. band
C. mixture
D. mess
【单选题】
The tennis players need total ___ during play.
A. concentration
B. section
C. depression
D. energy
【单选题】
He ___ that he was innocent.
A. announced
B. declared
C. disclosed
D. admitted
【单选题】
Columbus discovered America but did not ___ the new continent.
A. seek
B. investigate
C. search
D. explore
【单选题】
The trees ___their foliage every year.
A. repeat
B. grow
C. refresh
D. renew
【单选题】
Make a list of the various ___.
A. options
B. choice
C. optional
D. samples
【单选题】
I am well aware that this is a ___ job.
A. rough
B. tough
C. wealthy
D. rogue
【单选题】
I found their kindness quite ___.
A. strong
B. overweening
C. keen
D. overwhelming
【单选题】
The captain wasn’t ___ on having him in the team.
A. eager
B. keen
C. overwhelmed
D. anxious
【单选题】
He was ___at the prospect of seeing them again.
A. thrilling
B. blessed
C. thrilled
D. emotional
【单选题】
They ___ against travelling at night in such a dangerous country.
A. consul
B. advocate
C. counsel
D. recommend
【单选题】
It is absolutely vital that food supplied should be ___.
A. sustained
B. enhanced
C. exhausted
D. maintained
【单选题】
He must have had an accident, or he ___ then.
A. would have been here
B. had to be here
C. should be here
D. would be here
【单选题】
It was essential that the application forms ___ back before the deadline (截止日期).
A. must be sent
B. would be sent
C. be sent
D. were sent
【单选题】
We ___ our breakfast when an old man came to the door.
A. just have had
B. have just had
C. just had
D. had just had
【单选题】
The bridge was named ___ the hero who gave his life for the cause of the people.
A. after
B. with
C. by
D. from
【单选题】
It wasn’t such a good dinner ___ she had promised us.
A. that
B. which
C. as
D. what
【单选题】
The road now ___two kilometers beyond the river.
A. develops
B. extends
C. expands
D. widens
【单选题】
It was claimed that the level of alcohol in the man’s blood was ___ to cause an accident.
A. sufficient
B. adequate
C. enough
D. accurate
【单选题】
Medical care reform has become this country’s most important public health ___.
A. question
B. stuff
C. matter
D. problem
【单选题】
His retail business in the city___ rapidly between the wars.
A. enlarged
B. extended
C. widened
D. expanded
【单选题】
Many frogs ___ the sound of their voice using special sacs(囊) in their throat.
A. amplify
B. widen
C. expand
D. enlarge
【单选题】
Some old people don’t like pop songs because they cannot ___ so much noise.
A. resist
B. sustain
C. tolerate
D. undergo
【单选题】
I have kept that portrait where I can see it every day, as it always ___ me of my university days in London.
A. recollects
B. reminds
C. recalls
D. invokes
