【单选题】
在易燃易爆场所使用的照明灯具应采用()灯具。 ___
查看试卷，进入试卷练习
微信扫一扫，开始刷题
相关试题
【单选题】
照明系统中的每一单相回路上,灯具与插座的数量不宜超过()个。 ___
【单选题】
照明线路熔断器的熔体的额定电流取线路计算电流的()倍。 ___
【单选题】
正确选用电器应遵循的两个基本原则是安全原则和()原则。 ___
【单选题】
指针式万用表测量电阻时标度尺最右侧是()。 ___
【单选题】
指针式万用表一般可以测量交直流电压、()电流和电阻。 ___
【单选题】
装设接地线,当检验明确无电压后,应立即将检修设备接地并()短路。 ___
【单选题】
组合开关用于电动机可逆控制时,()允许反向接通。 ___
A. 可在电动机停后就
B. 不必在电动机完全停转后就
C. 必须在电动机完全停转后才
【判断题】
“止步,高压危险”的标志牌的式样是白底、红边,有红色箭头。
【判断题】
《中华人民共和国安全生产法》第二十七条规定:生产经营单位的特种作业人员必须按照国家有关规定经专门的安全作业培训,取得相应资格,方可上岗作业。
【判断题】
>用电笔验电时,应赤脚站立,保证与大地有良好的接触。
【判断题】
10kV以下运行的阀型避雷器的绝缘电阻应每年测量一次。
【判断题】
220V的交流电压的最大值为380V。
【判断题】
Ⅱ类设备和Ⅲ类设备都要采取接地或接零措施。
【判断题】
PN结正向导通时,其内外电场方向一致。
【判断题】
RCD的额定动作电流是指能使RCD动作的最大电流。
【判断题】
RCD的选择,必须考虑用电设备和电路正常泄漏电流的影响。
【判断题】
TT系统是配电网中性点直接接地,用电设备外壳也采用接地措施的系统。
【判断题】
按钮根据使用场合,可选的种类有开启式、防水式、防腐式、保护式等。
【判断题】
按照通过人体电流的大小,人体反应状态的不同,可将电流划分为感知电流、摆脱电流和室颤电流。
【判断题】
保护接零适用于中性点直接接地的配电系统中。
【判断题】
并联电容器所接的线停电后,必须断开电容器组。
【判断题】
剥线钳是用来剥削小导线头部表面绝缘层的专用工具。
【判断题】
测量电机的对地绝缘电阻和相间绝缘电阻,常使用兆欧表,而不宜使用万用表。
【判断题】
测量电流时应把电流表串联在被测电路中。
推荐试题
【单选题】
Chinese Mandarin (普通话) is ___ for foreigners to learn because the changes in the tone will totally change the meaning of words.
A. difficult
B. accessible
C. competitive
D. easy
【单选题】
Take action on those things that will have the biggest ___ impact on your life with the least amount of effort.
A. portable
B. positive
C. sophisticated
D. moderate
【单选题】
The adoption of this measure will greatly reduce the ___ of greenhouse gas emissions (排放物), which may help slow global warming.
A. loan
B. decline
C. release
D. response
【单选题】
I think I have a healthy lifestyle. I eat a lot of fruit and vegetables, and I’m a ___ drinker.
A. moderate
B. heavy
C. gradual
D. delicate
【单选题】
In a way the human race needs to improve its mental and physical qualities if it is to deal with the more and more ___ world and meet new challenges.
A. typical
B. complex
C. rational
D. orderly
【单选题】
If a person simply does not care about this activity, it’s ___ impossible to get him to participate.
A. barely
B. seldom
C. hardly
D. practically
【单选题】
Sometimes, even when the mind ___ functioning, the body keeps on working normally.
A. ceases
B. arouses
C. regulates
D. specializes
【单选题】
Jeffery expressed his ___ about the health and fitness of his co-workers, but they said they didn’t want to “waste time” on an exercise bike or jogging.
A. agony
B. concern
C. addiction
D. feedback
【单选题】
Such chemicals are indeed negatively ___ those humans to whom they are expose D.
A. risking
B. detecting
C. impacting
D. overwhelming
【单选题】
We regret for selling you the faulty product, and our company has agreed to ___ you by $500.
A. match
B. reverse
C. reward
D. compensate
【单选题】
This lecture taught me how to manage my time better to include my online studies in my busy ___.
A. schedule
B. outline
C. structure
D. responsibility
【单选题】
Generally speaking, an Irish person will not accept an offer straight away; he will ___ once or twice first before accepting it.
A. receive
B. decline
C. summarize
D. polish
【单选题】
There is every possibility that many species (物种) of animals will die out because of their disappearing food ___.
A. mode
B. source
C. pattern
D. foundation
【单选题】
As a college student, you should enjoy learning and get yourself ___ in those things that interest you.
A. concerned
B. devoted
C. involved
D. pursued
【单选题】
The name of Hitler (希特勒) has always been associated with war and ___ killing in the minds of those people who lived through World War Two.
A. imaginary
B. multiple
C. indispensable
D. massive
【单选题】
He works hard every day to make more money, but he ___ his health, time with his family, and the hobbies he once love D.
A. neglects
B. reminds
C. ceases
D. Declines
【单选题】
I asked a passenger sitting beside me if our train was the Westlake Express train, and he said he ___ of it.
A. not even heard
B. had not even heard
C. even not heard
D. ever had not heard
【单选题】
Whatever you say in the paper has to ___ your own thinking; hence simply repeating the professor’s opinions or whatever is in the readings will not get you very far.
A. ignore
B. arouse
C. reflect
D. release
【单选题】
We are sorry to know that they did not succeed ___ the project for lack of necessary funds.
A. to fulfill
B. to have fulfilled
C. in fulfilling
D. with fulfilling
【单选题】
It is surprising that fewer students were prepared to undertake the ___ to hand in written work on a regular basis, or to study over long periods.
A. engagement
B. commitment
C. authority
D. aspiration
【单选题】
Emily felt hurt and ___ by a close friend who had borrowed a considerable sum of money to pay for a house and then took it as a gift, never thinking of giving back the money.
A. conflicted
B. curbed
C. swollen
D. betrayed
【单选题】
In 1988 the old system was ___ in the country and a new system was introduced to take effect in 1990.
A. transmitted
B. abolished
C. assumed
D. compensated
【单选题】
We should not ___ ourselves to the classroom. We should go out of the classroom, see the world and talk to others as much as we can.
A. entertain
B. confine
C. assign
D. involve
【单选题】
I have always been grateful ___ Fred __the generous and helpful information when I was at the crossroads.
A. to … for
B. to … with
C. for … with
D. for … to
【单选题】
I think we both need to ___ the past, be happy about what we had for a time, learn from our experiences, and move on from there.
A. let go of
B. give authority to
C. make sense of
D. keep up with
【单选题】
My brother and I managed to ___ with each other and we soon made peace after a week’s quarrel.
A. heal
B. reconcile
C. respond
D. advocate
【单选题】
The two robbers in a stolen car tried to ___ a police roadblock (路障), but faile D.
A. break in
B. break off
C. break up
D. break through
【单选题】
Because of his long illness, Lee’s English level had dropped, but he was determined to ___ the other students by working harder.
A. put up with
B. catch up with
C. get along with
D. fill up with
【单选题】
We appreciate your efforts in making changes in your schedule and think that this new arrangement is now ___ to us.
A. agreeable
B. sustainable
C. portable
D. indispensable
【单选题】
The woman who died in a car crash last Saturday in the suburbs has been ___ as Kate Johnson, a 25-year-old office clerk.
A. justified
B. identified
C. notified
D. classified
【单选题】
My nephew failed in the College Entrance Examination, and we were all very sorry that he did not ___ to the university.
A. take it
B. get it
C. make it
D. succeed it
【单选题】
Almost half of that group will experience stress ___ enough to call for professional help.
A. tense
B. moderate
C. bearable
D. intense
【单选题】
If you grow too fast your entire economy could completely shut down and bring growth to a(n) ___.
A. halt
B. cease
C. peak
D. epidemic
【单选题】
I tried my best to drive inside in order to avoid the edges that might make me ___ the steep slope.
A. slip down
B. settle down
C. bring down
D. turn down
【单选题】
When the driver heard that there was a bomb on the bus, he immediately ___ to the side of the highway and radioed the police.
A. put out
B. took off
C. pulled over
D. slipped off
【单选题】
She was very ___ to become a manager in our customers’ office, but finally accepted our offer.
A. eager
B. intelligent
C. ridiculous
D. reluctant
【单选题】
In the race, it looked as if he would be the first, but then another young man who was close behind him put on speed and ___ by a few seconds.
A. beat him for it
B. beat him to it
C. beat him up
D. beat it to him
【单选题】
It is really helpful to have someone like you that we can ___ and count on during difficult times.
A. lean on
B. get to
C. hang on
D. get by
【单选题】
Women have a greater ability to ___ names with faces than men do, and they are also better at recalling lists.
A. associate
B. compare
C. engage
D. involve
【单选题】
He was always ready to help others and managed to ___ his friends ____being hurt.
A. expose … to
B. confine …to
C. restrict … from
D. shield … from
