相关试题
【单选题】
在铝绞线中加入钢芯的作用是___。
A. 提高导电能力
B. 增大导线面积
C. 提高机械强度
【单选题】
ⅱ类手持电动工具是带有___绝缘的设备。
【单选题】
在检查插座时,电笔在插座的两个孔均不亮,首先判断是___。
【单选题】
高压验电器的发光电压不应高于额定电压的___%。
【单选题】
低压电工作业是指对___v以下的电气设备进行安装、调试、运行操作等的作业。
【单选题】
测量接地电阻时,电位探针应接在距接地端___m的地方。
【单选题】
如果触电者心跳停止,有呼吸,应立即对触电者施行___急救。
A. 仰卧压胸法
B. 胸外心脏按压法
C. 俯卧压背法
【单选题】
具有反时限安秒特性的元件就具备短路保护和___保护能力。
【单选题】
图是___触头。
A. 延时闭合动合
B. 延时断开动合
C. 延时断开动断
【单选题】
对于低压配电网,配电容量在100kw以下时,设备保护接地的接地电阻不应超过___ω。
【单选题】
对照电机与其铭牌检查,主要有___、频率、定子绕组的连接方法。
【单选题】
对电机内部的脏物及灰尘清理,应用___。
A. 湿布抹擦
B. 布上沾汽油、煤油等抹擦
C. 用压缩空气吹或用干布抹擦
【单选题】
串联电路中各电阻两端电压的关系是___。
A. 各电阻两端电压相等
B. 阻值越小两端电压越高
C. 阻值越大两端电压越高
【单选题】
尖嘴钳150mm是指___。
A. 其绝缘手柄为150mm
B. 其总长度为150mm
C. 其开口150mm
【单选题】
导线接头连接不紧密,会造成接头___。
【单选题】
按国际和我国标准,___线只能用做保护接地或保护接零线。
【单选题】
使用竹梯时,梯子与地面的夹角以___°为宜。
【单选题】
单相电度表主要由一个可转动铝盘和分别绕在不同铁芯上的一个___和一个电流线圈组成。
【单选题】
指针式万用表测量电阻时标度尺最右侧是___。
【单选题】
脑细胞对缺氧最敏感,一般缺氧超过___min就会造成不可逆转的损害导致脑死亡。
【单选题】
在电力控制系统中,使用最广泛的是___式交流接触器。
【单选题】
低压电器可归为低压配电电器和___电器。
【单选题】
当车间电气火灾发生时,应首先切断电源,切断电源的方法是___。
A. 拉开刀开关
B. 拉开断路器或者磁力开关
C. 报告负责人请求断总电源
【单选题】
当电压为5v时,导体的电阻值为5欧,那么当电阻两端电压为2v时,导体的电阻值为___欧。
【单选题】
一般照明场所的线路允许电压损失为额定电压的___。
【单选题】
合上电源开关,熔丝立即烧断,则线路___。
【单选题】
线路单相短路是指___。
A. 功率太大
B. 电流太大
C. 零火线直接接通
【单选题】
___是保证电气作业安全的技术措施之一。
【单选题】
电容器在用万用表检查时指针摆动后应该___。
【单选题】
___仪表可直接用于交、直流测量,且精确度高。
【单选题】
测量电动机线圈对地的绝缘电阻时,摇表的“l”、“e”两个接线柱应___。
A. “e”接在电动机出线的端子,“l”接电动机的外壳
B. “l”接在电动机出线的端子,“e”接电动机的外壳
C. 随便接,没有规定
【单选题】
更换熔体或熔管,必须在___的情况下进行。
【单选题】
在半导体电路中,主要选用快速熔断器做___保护。
推荐试题
【单选题】
My hands and feet were ___ with cold as I waited for the bus.
A. cliff
B. still
C. stiff
D. stick
【单选题】
The Foreign Minister made an excellent ___ on the current international situation.
A. committee
B. command
C. comment
D. commission
【单选题】
Over a third of the population was estimated to have no ___ to the health service.
A. assessment
B. assignment
C. exception
D. access
【单选题】
My father seemed to be in no ___ to look at my school report.
A. mood
B. emotion
C. attitude
D. feeling
【单选题】
He saw the publication of this book as an embarrassing invasion of his ___.
A. secret
B. privacy
C. private
D. piracy
【单选题】
I think I would have died of ___.
A. embarrass
B. embarrassing
C. embarrassed
D. embarrassment
【单选题】
He had an ___ at a restaurant in Greek Street at eight.
A. engagement
B. engage
C. contract
D. promise
【单选题】
These companies often encounter many ___ impediments to investment.
A. invisible
B. edible
C. feasible
D. capable
【单选题】
30 percent of reptiles, birds, and fish are currently ___ with extinction.
A. treated
B. threatened
C. endangered
D. threatening
【单选题】
They have a stronger ___ of the importance of economic incentives.
A. appreciation
B. learning
C. concept
D. idea
【单选题】
I believe I am capable of ___ the political consequences accurately.
A. guessing
B. evaluating
C. calculating
D. computing
【单选题】
When he opened the door, he used too much force and ___ the key.
A. trailed
B. varied
C. wicked
D. twisted
【单选题】
I’m very sorry to have ___ you with so many questions on such an occasion.
A. offended
B. impressive
C. bothered
D. interfered
【单选题】
It is sometimes difficult for young people from the countryside to ___ well to life in the big city.
A. suit
B. adapt
C. regulate
D. coordination
【单选题】
Our guide gave us a detailed ___of this painting but we still do not understand.
A. authority
B. interpretation
C. instruction
D. institution
【单选题】
If you want to ___ the wood, cut it with the grain, not against it.
A. break
B. burn
C. split
D. divide
【单选题】
They have a stronger ___ of the importance of economic incentives.
A. appreciation
B. learning
C. conception
D. idea
【单选题】
I believe I am capable of ___ the political consequences accurately.
A. guessing
B. betting
C. calculating
D. computing
【单选题】
30 percent of reptiles, birds, and fish are currently ___ with extinction.
A. treated
B. threatened
C. danger
D. threatening
【单选题】
Workers should occasionally walk around, ___ and avoid prolonged periods at the desk.
A. pull
B. lengthen
C. strain
D. stretch
【单选题】
These companies often encounter many ___ impediments to investment.
A. invisible
B. edible
C. feasible
D. capable
【单选题】
Running a kitchen ___a great deal of discipline and speed.
A. including
B. involving
C. involves
D. composes
【单选题】
He had an ___ at a restaurant in Greek Street at eight.
A. engagement
B. engage
C. contract
D. promise
【单选题】
I think I would have died of ___.
A. embarrass
B. embarrassing
C. embarrassed
D. embarrassment
【单选题】
He saw the publication of this book as an embarrassing invasion of his ___.
A. secret
B. privacy
C. private
D. piracy
【单选题】
The trade imbalance is likely to rise again in 2020. ___ a new set of policy actions will be required soon.
A.
B. ecause B. Nevertheless
C. Hence
D. Therefore
【单选题】
Stratford police refuse to comment ___ whether anyone has been arrested.
A. about
B. on
C. at
D. with
【单选题】
The world will be different, and we will have to be prepared to ___ to the change.
A. adopt
B. adapt
C. accustom
D. adept
【单选题】
The company has launched a campaign of television ___ and leaflets.
A. commercials
B. commences
C. commerce
D. commercialization
【单选题】
The general secretary may ___ the president at official ceremonies.
A. present
B. represent
C. representative
D. stand
【单选题】
He ___ her arms behind her back and clipped a pair of handcuffs on her wrists.
A. dragged
B. pulled
C. stretched
D. twisted
【单选题】
Suppose that when I come back in ten years’ time all these old houses ___ down.
A. will have been pulled
B. will have pulled
C. will be pulling
D. will be pulled
【单选题】
The picture exhibition bored me to death. I wish I ___ to it.
A. have not gone
B. did not go
C. had not gone
D. should not have gone
【单选题】
An investigation was made into the accident ___ fifty people were killed.
A. for that
B. where
C. when
D. in which
【单选题】
___ with the picture, Mary tore it to pieces.
A. Dissatisfying thoroughly
B. Being thoroughly dissatisfied
C. To dissatisfy thoroughly
D. To be thoroughly dissatisfied
【单选题】
She was so angry that she felt like ___ something at him.
A. to throw
B. to have thrown
C. throwing
D. having thrown
【单选题】
If you want to know the train schedule, please ___ at the booking office.
A. acquire
B. inquire
C. request
D. require
【单选题】
My brother’s plans are very ___; he wants to master English, French and Spanish before he is sixteen.
A. arbitrary
B. aggressive
C. ambitious
D. abundant
【单选题】
Housewives who do not go out to work often feel they are not working to their full ___.
A. capacity
B. strength
C. length
D. possibility
【单选题】
Water and air are ___ to human beings. We cannot live without them.
A. harbor
B. function
C. definite
D. essential
