【单选题】
并联电容器运行中,当电流超过额定电流___倍时,应立即退出运行。
A. 1.1
B. 1.2
C. 1.3
D. 1.5
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相关试题
【单选题】
吸收电流和充电电流在一定时间后都趋近于___。
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运行中的电流互感器类似工作在___状态的变压器。
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E类火灾场所(物体带电燃烧的火灾)的灭火器最低配置标准不应低于___m2/A。
A. 20~100
B. 40~100
C. 50~100
D. 60~100
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频敏变阻器是一种有独特结构的___。
A. 磁元件
B. 电元件
C. 有触点元件
D. 无触点元件
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胸外按压法要以均匀速度进行,每分钟至少___次,按压和放松时间相等。
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隔离开关是指___接通和断开电流任务,将电路与电源隔离,以保证检修人员检修时的安全开关。
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室内单台电气设备的油量在100kg以上时设置档油设施的容积应按容纳___油量设计。
A. 0.05
B. 0.1
C. 0.15
D. 0.2
【单选题】
在NPN型晶体三极管放大电路中,基极与发射极短路,则晶体管___。
A. 深度饱和
B. 将截止
C. 集电极正偏
D. 发射结反偏
【单选题】
抗静电添加剂,加入产生静电的绝缘材料以后,能增加材料的___。
A. 吸湿性
B. 干燥
C. 绝缘电阻
D. 导电体
【单选题】
检查10kV及以下电力电缆的耐压强度,应进行___试验。
A. 工频耐压
B. 绝缘电阻
C. 直流耐压
D. 泄漏电流
【单选题】
兆欧表由于导入可动线圈的游丝不产生力矩,所以摇表在使用之前的指针可以停留在___位置。
A. 固定在零位
B. 固定在无穷大
C. 中间
D. 任意
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用脚扣在杆上作业只宜___使用。
A. 长时间
B. 水泥电杆
C. 木杆
D. 短时间
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按工作状态指示和工作情况要求,选择按钮的___。
【单选题】
由于雷电放电途径受很多因数的影响,一般要求保护范围内被冲击中的概率在___以下即可。
A. 0.5%
B. 0.4%
C. 0.2%
D. 0.1%
【单选题】
金属外壳的II类设备,有基本上连城一体的金属外壳,其内部采用___。
A. 基本绝缘
B. 附加绝缘
C. 双重绝缘
D. 加强绝缘
【单选题】
电弧温度可高达___。
A. 1000℃
B. 3000℃
C. 3000~6000℃
D. 6000℃以上
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触电者神志不清,有呼吸,但心跳停止,应立即进行___。
A. 人工呼吸
B. 胸外胸脏按压
C. 心肺复苏
D. 电话联系医生
【单选题】
用高压验电器时要防止发生相间短路事故,人体与带电体应保持足够的安全距离如10kV高压___m以上。
A. 0.4
B. 0.5
C. 0.7
D. 1
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遮拦高度应不低于___m。
A. 2.2
B. 1.7
C. 1.5
D. 1
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横担一般是水平安装,其最大斜度不应超过横担长度的___。
A. 0.01
B. 0.015
C. 0.02
D. 0.03
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安全标示牌按放置区域的用途可分为___允许、警告、禁止四类。
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根据燃烧的定义,___不是燃烧中的常见现象。
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一般接触器的机械寿命达___。
A. 400万次
B. 500万次
C. 600~1000万次
D. 1000万万次
【单选题】
工作负责人可以填写工作票,但___签发工作票。
A. 不可以
B. 也可以
C. 代替
D. 领导批准也可以
【单选题】
绝缘手套应储存在相对湿度___的库房中。
A. 30%~40%
B. 40%~50%
C. 50%~80%
D. 80%以上
【单选题】
统计资料表明,心跳呼吸停止,在1min内进行抢救,约___可以救活。
A. 50%
B. 60%
C. 70%
D. 80%
【单选题】
成年男性的平均感知电流值约为___mA。
A. 0.5
B. 0.7
C. 1.1
D. 2
【单选题】
三相四线式380V电源供电的电气设备,应选择___RCD。
A. 三极三线
B. 三极四线
C. 四极四线
D. 两极三线
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施工现场临时用电,同一横担上导线的相序排列,面向负荷从左起是___。
A. L1,L2,PE,L3,N
B. PE,L1,N,L2,L3
C. L1,N,L2,L3,PE
D. 任意排列
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交流电的摆脱电流比直流电的摆脱电流___。
【单选题】
IT系统是配电网___的系统。
A. 直接接地
B. 不接地
C. 经低阻抗接地
D. 大接地电流系统
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全欧姆定律指出,电流的大小与电源内部电阻与负载电阻之和成___。
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剩余电流动作保护器安装在线路末端应按能在___S内切断电源整定。
A. 0.01
B. 0.1
C. 0.15
D. 0.2
【单选题】
用500型万用表测量电阻约为10kΩ电阻,其电阻档应放在___档上。
A. R×10
B. R×100
C. R×1000
D. R×10K
【单选题】
___往往会直接引发火灾,是防火防爆工作重点。
A. 锅炉爆炸
B. 液化气爆炸
C. 化学性爆炸
D. 核爆炸
【单选题】
架空电力线路的架设放线,导线间最大弧线垂值偏差___mm。
【单选题】
接地线应采取多股软裸铜线,其截面积应符合___的要求。
A. 机械强度
B. 柔韧性
C. 短路电流
D. 绝缘电阻
【单选题】
一般来说,男性的摆脱电流比女性的摆脱电流要___。
A. 大
B. 小
C. 一样
D. 有时大有时小
【单选题】
静电中和法可用来消除___上的静电。
A. 导体
B. 半导体
C. 绝缘体
D. 所有材料
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The author of the report is well___with the problems in the hospital because he has been working there for many years.
A. informed
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The manager lost his ___ just because his secretary was ten minutes late.
A. mood
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Many Europeans___ the continent of Africa in the 19th century.
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A. seek
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The pressure ___causes Americans to be energetic, but it also puts them under a constant emotional strain.
A. to compete
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Having decided to rent a flat, we ___ contacting all the accommodation agencies in the city.
A. set about
B. set on
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The old couple decided to ___ a boy and a girl though they had three children of their own.
A. adapt
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Mike was being ___for violent tendencies.
A. contended
B. consulted
C. counselled
D. insulted
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I will___ Mr. Walters on this point.
A. refer to
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C. contribute to
D. defer to
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What happens in the next few days is___to our success.
A. critical
B. critic
C. prior
D. valid
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She won’t___that there is a problem.
A. confer
B. concern
C. acknowledge
D. contemplate
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This offer is___ for travel before the end of April.
A. effective
B. ineffective
C. invalid
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___ to British universities depends on examination results.
A. Admittance
B. Entry
C. Admission
D.
E. ntrance
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The database is only ___ by authorized managers.
A. proved
B. accessible
C. approved
D. access
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This traditional ___ is of indigo blue.
A. clothes
B. diversity
C. costume
D. institution
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These cigarettes are a ___ of the best tobaccos.
A. blend
B. band
C. mixture
D. mess
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The tennis players need total ___ during play.
A. concentration
B. section
C. depression
D. energy
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He ___ that he was innocent.
A. announced
B. declared
C. disclosed
D. admitted
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Columbus discovered America but did not ___ the new continent.
A. seek
B. investigate
C. search
D. explore
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The trees ___their foliage every year.
A. repeat
B. grow
C. refresh
D. renew
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Make a list of the various ___.
A. options
B. choice
C. optional
D. samples
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I am well aware that this is a ___ job.
A. rough
B. tough
C. wealthy
D. rogue
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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
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They ___ against travelling at night in such a dangerous country.
A. consul
B. advocate
C. counsel
D. recommend
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It is absolutely vital that food supplied should be ___.
A. sustained
B. enhanced
C. exhausted
D. maintained
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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
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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
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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
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The bridge was named ___ the hero who gave his life for the cause of the people.
A. after
B. with
C. by
D. from
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It wasn’t such a good dinner ___ she had promised us.
A. that
B. which
C. as
D. what
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The road now ___two kilometers beyond the river.
A. develops
B. extends
C. expands
D. widens
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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
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Medical care reform has become this country’s most important public health ___.
A. question
B. stuff
C. matter
D. problem
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His retail business in the city___ rapidly between the wars.
A. enlarged
B. extended
C. widened
D. expanded
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Many frogs ___ the sound of their voice using special sacs(囊) in their throat.
A. amplify
B. widen
C. expand
D. enlarge
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Some old people don’t like pop songs because they cannot ___ so much noise.
A. resist
B. sustain
C. tolerate
D. undergo
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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
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The article suggests that when a person is under unusual ___ he should be especially careful to have a well-balanced diet.
A. weight
B. stress
C. press
D. nerve