相关试题
【判断题】
绝缘棒在闭合或拉开高压隔离开关和跌落式熔断器,装拆携带式接地线,以及进行辅助测量和试验使用。
【判断题】
验电是保证电气作业安全的技术措施之一。
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在安全色标中用绿色表示安全、通过、允许、工作。
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相同条件下,交流电比直流电对人体危害较大。
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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。
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通电时间增加,人体电阻因出汗而增加,导致通过人体的电流减小。
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根据用电性质,电力线路可分为动力线路和配电线路。
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过载是指线路中的电流大于线路的计算电流或允许载流量。
【判断题】
在选择导线时必须考虑线路投资,但导线截面积不能太小。
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异步电动机的转差率是旋转磁场的转速与电动机转速之差与旋转磁场的转速之比。
【判断题】
对绕线型异步电机应经常检查电刷与集电环的接触及电刷的磨损,压力,火花等情况。
【判断题】
对电机轴承润滑的检查,可通电转动电动机转轴,看是否转动灵活,听有无异声。
【判断题】
同一电器元件的各部件分散地画在原理图中，必须按顺序标注文字符号。
【判断题】
能耗制动这种方法是将转子的动能转化为电能,并消耗在转子回路的电阻上。
【判断题】
锡焊晶体管等弱电元件应用100W的电烙铁。
【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】
移动电气设备可以参考手持电动工具的有关要求进行使用。
【判断题】
当灯具达不到最小高度时,应采用24V以下电压。
【判断题】
低压验电器可以验出500V以下的电压。
【判断题】
危险场所室内的吊灯与地面距离不少于3m。
【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。
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为了安全可靠,所有开关均应同时控制相线和零线。
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在带电灭火时,如果用喷雾水枪应将水枪喷嘴接地,并穿上绝缘靴和戴上绝缘手套,才可进行灭火操作。
【判断题】
电工特种作业人员应当具备高中或相当于高中以上文化程度。
【判断题】
取得高级电工证的人员就可以从事电工作业。
【判断题】
当导体温度不变时,通过导体的电流与导体两端的电压成正比,与其电阻成反比。
【判断题】
摇测大容量设备吸收比是测量(60秒)时的绝缘电阻与(15秒)时的绝缘电阻之比。
【判断题】
用万用表R×1KΩ欧姆档测量二极管时,红表笔接一只脚,黑表笔接另一只脚测得的电阻值约为几百欧姆,反向测量时电阻值很大,则该二极管是好的。
【判断题】
接地电阻测试仪就是测量线路的绝缘电阻的仪器。
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测量电流时应把电流表串联在被测电路中。
【判断题】
从过载角度出发,规定了熔断器的额定电压。
【判断题】
万能转换开关的定位结构一般采用滚轮卡转轴辐射型结构。
推荐试题
【单选题】
12. We all know that learning a foreign language _______ time and effort.
A. requires B. reduces C. removes D. repeats
【单选题】
13. Her son __________ Coke, but now he __________ milk．
A. is used to drinking; used to drink B. used to drink; uses to drink
C. used to drink; is used to drinking D. is used to drink; is drinking
【单选题】
14. I don’t know the teacher is talking with Miss Wang．
A. what B. whom C. who D. which
【单选题】
15.Millie does __________ that many people are thankful to her．
A. such an important and helpful job B. so important and helpful work
C. a very important and helpful job D. such an important and helpful work
【单选题】
16. I think eating more vegetables is good _______ our health.
—Yes, I agree _______ you.
A. at, to B. for, with C. to, to D. for, to
【单选题】
17. I often go on holiday with my parents _____ summer.
A. in B. at C. on D. of
【单选题】
18. I called you at 4:00 yesterday afternoon, but nobody answered.
Sorry, I ______ with my friends at that time.
A. had swum B. swam C. would swim D. was swimming
【单选题】
19.––Who is on the playground? ---__________．
A. Never B. None C. No one D. A lot
【单选题】
20. The schoolboy ______ a blind man cross the street yesterday.
A. helps B. helped C. will help D. has helped
【单选题】
21. —The 2010 World Expo which will last 184 days will be held in Shanghai on May 1st.
—________exciting news! We shall try our best to support it.
A. How B. How an C. What D. What an
【单选题】
22. They preferred ______ in bed rather than _____ horses．
A. to lie; to ride B. lying; riding C. lying; ride D. to lie; ride
【单选题】
23. —What was Jim wearing at the party?
— Nothing _______. He was in his usual shirt and jeans.
A. special B. simple C. important D. interesting
【单选题】
24. The 2016 Olympic Games ________ in Brazil. Would you like to go there?
Maybe, if possible.
A. are held B. will be held C. were held D. have been held
【单选题】
25. — David, look at the man in white over there．Can you tell me _______ ?
—He is a doctor．
A. who is he B. who he is C．what does he do D. what he does
【单选题】
( ) 26.With help from a Mr. H, you can__________.
A. stop wearing your watch B. get new books and objects
C. finish your homework on time D. know when parents or teachers are near
【单选题】
( ) 27. A PENGO WATCH CONTROL can help you to ______________.
A. repair your TV B. put away your books and objects
C. become a James Bond D. get a daily weather report
【单选题】
( ) 28. You can get your Mr. H for___________.
A. $299 B. $499 C. $199 D. $99
【单选题】
( ) 29. When was canned food invented?
A. In 1870. B. In 1810. C. In 1902. D. In 1926.
【单选题】
( ) 30. After the trip to the Arctic, Clarence Birdseye invented ____________.
A. canned food B. can openers
C. frozen food D. air conditioning
【单选题】
( ) 31. Changes in weather _____________ in Willis Carrier's company.
A. helped to keep food B. made rooms comfortable
C. caused health problems D. hurt printing paper
【单选题】
( ) 32. According to the passage, which of the following may lead to inventions?
A. People's needs. B. Public support.
C. Modern technology. D. Practical suggestions.
【单选题】
( ) 33. 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】
( ) 34. 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】
( ) 35. 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】
( ) 36. 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】
( ) 37. The Chinese Yellow Sea Wetlands are in the _______ of China．
A．south B．east C．west D．north
【单选题】
( ) 38. Usually the weather in the wetlands is _______．
A．hot B．pleasant C．cold D．dry
【单选题】
( ) 39. The World Wetlands Day is on _______．
A．February 2 B．June 25 C．April 22 D．March
【单选题】
( ) 40. We must protect wetlands because _______．
A．they are home for wildlife B．they can prevent flood
C．they can offer food to the animals and birds D．all of the above
【单选题】
) 1. —Is it far from here to the bank?
—Not very, only________．
A. 20 minute’s walk B. 20 minutes walk
C. 20 minutes’ walk D. 20 minutes’ walks
【单选题】
2. — After discussing, the students ________ some good ideas to work on the project.
— Thats great!
A. put up B. set up C. caught up with D. came up with
【单选题】
3. Yesterday Tommy walked past my table and ______ my bowls and dishes.
He should be careful next time.
A. knocked off B. took off C. showed off D. turned off
【单选题】
4.We don’t have enough nurses to look after patients．At least ___ nurses are needed．
A. ten another B. more ten C. another ten D. other ten
【单选题】
5. — Zhao Rui, it’s said that many famous singers will come to Yangzhou on April 18th. How about watching the evening show there?
—________! Let’s ask Huang Tao to go with us.
A. Best wishes B. Sounds great C. Good luck D. That’s OK
【单选题】
6.—Hello! This is Henry Speaking．I’d like to speak to your father．
—Sorry, he has Shanghai．
A. been in B. been to C. come to D. gone to
【单选题】
7. — It’s difficult for the village children to cross the river for school．
— I think a bridge ______ over the river．
A. was built B. is being built C. has been built D. should be built
【单选题】
8. —Where would you like to go, Jinan or Qufu?
— ．I only want to go to Qingdao．
A. Each B. Either C. Neither D. All
【单选题】
9 — The documentary A Bite Of China II is quite popular around China recently. How do you like it? ______.
A. I think so B. Pretty good C. Its my pleasure D. All right
【单选题】
10. There are three English-books on the shelf, but ______ of them is mine.
A. both B. neither C.all D. none
【单选题】
11. When the parents arrived at the hall, the students _______ their projects.
A. have finish B. finished C. had finished D. are finishing
