【单选题】
20.习惯上人们规定正电荷移动的方向为( )的方向。《车辆电工》P4___
A. 电流
B. 电压
C. 交流电
D. 直流电
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】
21.电路中任意两点之间的电位差称为这两点间的（ ）。《车辆电工》P4___
【单选题】
22.电源内部推动电流的力量叫做电源（ ）。《车辆电工》P4___
【单选题】
23.电路都由（ ）、负载、中间环节等组成。《车辆电工》P4___
【单选题】
24.短路时电流会超过正常情况下很多倍,短时间内会生大量的（ ）,轻则使电源和电气设备烧毁,重则引起火灾。《车辆电工》P5___
【单选题】
25.同一材料的导线，在粗细相同的情况下，（ ）。《车辆电工》P5___
A. 导线越长，电阻越大
B. 导线越长，电阻越小
C. 导线越短，电阻越大
D. 导线长度与电阻无关
【单选题】
26.当电流通过金属导体时会遇到阻力，导体这种对电流起阻碍作用的能力叫做（ ）。《车辆电工》P5___
【单选题】
27.由欧姆定律定律变换式可知：一段导体的电阻与其两端所加的（ ）。《车辆电工》P6___
A. 电压成正比
B. 电流成反比
C. 电压成正比，电流成反比
D. 与电压、电流无关
【单选题】
28.将电阻R1、R2、R3串联起来后接到电源上，其总电压为（ ）《车辆电工》P6___
A. U=U1+U2+U3
B. U=U1=U2=U3
C. U=（U1+U2+U3）/2
D. 无法确定
【单选题】
29.导体材料电阻率越大，导电（ ）。《车辆电工》P6___
A. 越好
B. 越差
C. 不变
D. 无法确定
【单选题】
30.下列材料中，电阻率最大的（ ）。《车辆电工》P6___
【单选题】
31.在串联电路中，流过电阻的（ ）相等。《车辆电工》P7___
【单选题】
32.并联电路各电阻两端（ ）相同。《车辆电工》P7___
【单选题】
33.电路中串联的电阻越多，其等效电阻越（ ）。《车辆电工》P7___
A. 越大
B. 越小
C. 不变
D. 无法确定
【单选题】
34.电路中并联的电阻越多，其等效电阻越（ ）。P7___
A. 越大
B. 越小
C. 不变
D. 无法确定
【单选题】
35.电路的电阻一定时，电阻所消耗的电功率与电阻两端电压的平方成（ ）。《车辆电工》P9___
A. 正比
B. 反比
C. 不变
D. 无法确定
【单选题】
36.电气设备在额定电压消耗额定功率时的工作状态，称为（ ）。《车辆电工》P9___
【单选题】
37.用来储存电荷的容器叫（ ）。《车辆电工》P10___
A. 电感器
B. 电容器
C. 电量器
D. 电流器
【单选题】
38.直流电路中，电容相当于起到（ ）作用。《车辆电工》P10___
【单选题】
39.电容器不论是充电或放电，其两端的（ ）是不能突变的，只能随时间从一个数值过渡到另一个数值。《车辆电工》P11___
【单选题】
40．环形电流的方向跟它的磁力线方向之间的关系，可用（ ）来判定。《车辆电工》P13___
A. 右手定则
B. 左手定则
C. 欧姆定律
D. 牛顿第一定律
【单选题】
41.用左手定则判定通电导体在磁场中的（ ）。《车辆电工》P15___
A. 受力方向
B. 受力大小
C. 电流方向
D. 电流大小
【单选题】
42.减少涡流的办法是铁芯间彼此（ ）。《车辆电工》P19___
【单选题】
43.交流电是由（ ）产生的。《车辆电工》P19___
A. 交流发电机
B. 直流发电机
C. 直流电动机
D. 交流电动机
【单选题】
44.直流电路中，电感相当于起到（ ）作用。《车辆电工》P22___
【单选题】
45.交流电路中无功功率的“无功”的实质是（ ）。《车辆电工》P23___
【单选题】
46.DC600V电源漏电保护值出厂时预设为( )mA。《客车DC600V供电系统原理与检修》P99___
A. 100
B. 120
C. 150
D. 200
【单选题】
47.三相电源相电压是对称的，即有效值相等，仅相位互差（ ）°。《车辆电工》P27___
【单选题】
48.交流接触器有（ ）对主触点和若干辅助触点。《车辆电工》P43___
【单选题】
49.用万用表检测晶体二极管时，如果二极管的正、反电阻都接近于（ ），说明该二极管内部断路损坏。《车辆电工》P57___
A. 无穷大
B. 0Ω
C. 相差不大
D. 相差１kΩ
【单选题】
50.用万用表检测晶体二极管时，如果正、反向电阻均为（ ）Ω，说明明该二极管已被击穿短路。《车辆电工》P57___
A. 无穷大
B. 0Ω
C. 相差不大
D. 相差１kΩ
【单选题】
51.场效应管是电压控制型元件，它有（ ）个电极《车辆电工》P63___
【单选题】
52.电气电路图中，保护器件的字母代码是（ ）。《车辆电工》P86___
【单选题】
53.电气电路图中，电阻的字母代码是（ ）。《车辆电工》P86___
【单选题】
54.电气电路图中，电动机的字母代码是（ ）。《车辆电工》P86___
【单选题】
55.电气电路图中，继电器、接触器的字母代码是（ ）。《车辆电工》P86___
【单选题】
56.电气电路图中，电力电路开关的字母代码是（ ）。《车辆电工》P86___
【单选题】
57.看电路图时，通常要（ ）看。《车辆电工》P88___
A. 从左往右
B. 从右往左
C. 从上往下
D. 从下往上
【单选题】
58.我国规定的安全电压为：50～500Hz的交流电压额定值有（ ）四种。《车辆电工》P101___
A. 36V、24V、12V、6V
B. 48V、24V、12V、6V
C. 48V 、36V、24V、12V
D. 55V 、48V 、36V、24V
【单选题】
59.我国规定的安全电压为：直流电压额定值有（ ）四种。《车辆电工》P101___
A. 36V、24V、12V、6V
B. 48V、24V、12V、6V
C. 48V 、36V、24V、12V
D. 55V、48V 、24V、12V
【单选题】
60.当使用大于（ ）V的安全电压时，必须有防止人身接触及带电体的保护措施。《车辆电工》P101___
推荐试题
【填空题】
46.无坝取水渠首一般由___，___和___三部分构成。
【填空题】
48.___由蓄水大坝，水电站厂房，通航建筑物船闸及升船机等主要建筑物组成。
【填空题】
49.利用潮水涨落产生的水位差所具有的势能来发电的方法是___。
【填空题】
50.___基础是指桩，墩，沉井，沉箱和地下连续墙等基础。
【填空题】
51.按桩的施工方法，桩分为___和___两类。
【填空题】
52.即可用作深基坑的支护结构，又可作为深基坑的支护和建筑物地下室外墙的是___。
【填空题】
53.砌筑用脚手架是砌筑过程中堆放材料和工人进行操作的___。
【填空题】
54.混凝土浇筑包括___和___两个过程。
【填空题】
55.无粘结预应力混凝土结构在张拉后容许预应力筋对周围混凝土发生___滑动。
【填空题】
56.斜拉桥是新型的桥梁形式，这种形式大桥的主桥分为___和___两大部分。
【填空题】
57.___和___是国际通行的工程建设项目组织实施方式。
【填空题】
58.BIM 中的图形是赋予了___属性的实体。
【填空题】
59.BIM 是指建筑物在设计和建造过程中，创建和使用的“___”。
【单选题】
The word "wag" (Line 1, Para.1) most probably means _________.
A. move
B. shake
C. bite
D. play
【单选题】
The video cameras were used to catch the dogs' responses because ___________.
A. the dogs were put in the wooden boxes
and tested one at a time
B. it was easier to catch the dogs’s response changes in the tail wagging
C. they enabled the dogs’owners to know
about their dogs’; habit
D. the dogs wagged their tails in different
directions when they were in different
moods
【单选题】
When there are no stimuli, a dog will ___________.___
A. wag to the right
B. no wag at all
C. wag to the left
D. wag to the left and then wag to the right
【单选题】
The purpose of doing the experiment is _________.___
A. to train dogs for their owners
B. to help dogs find companion
C. to help people choose their pet dogs
D. to help people judge the mood of dogs
【单选题】
The underlined word "they" in the last sentence refers to __________.___
A. the trainers
B. the systems
C. the researchers
D. the dogs
【单选题】
The new law passed in Rome will ________.___
A. help improve fishing environment
B. stop people from catching goldfish
C. guarantee better conditions for goldfish
D. discourage keeping goldfish at home
【单选题】
People in Rome believe that the civilization of a city can be judged by _________.___
A. awareness of animal protection
B. exchanges with other cities
C. protection of ancient ruins
D. recognition of animal lovers
【单选题】
The underlined word "compassion" in Para 2 is the closest in meaning to __________.___
A. support
B. pity
C. help
D. love
【单选题】
People may break the law in Turin if they ________.___
A. keep their dogs or cats in cars
B. shut their dogs home all day long
C. raise their cats near ancient ruins
D. feed homeless animals in car parks
【单选题】
We can infer from the passage that _________.___
A. the owners can leave their dogs in hot cars
B. the cat only lives in modern life
C. the new law can prevent cruelty to animals
D. the new law gives recognition to the
people who feed homeless cat
【单选题】
If a person finds getting up early a problem, most probably ________.___
A. he is a lazy person
B. he refuses to follow his own energy cycle
C. he is not sure when his energy is low
D. he is at his peak in the afternoon or evening
【单选题】
Which of the following may lead to family quarrels according to the passage?___
A. Unawareness of energy cycles.
B. Familiar monologues.
C. A change in a family member's energy cycle.
D. Attempts to control the energy cycle of other family members.
【单选题】
If one wants to work efficiently at his low point in the morning, he should __________.___
A. change his energy cycle
B. overcome his laziness
C. get up earlier than usual
D. go to bed earlier
【单选题】
You are advised to rise with a yawn and stretch because it will __________.___
A. help to keep your energy for the day's work
B. help you to control your temper early in the day
C. enable you to concentrate on your routine work
D. keep your energy cycle under control all day
【单选题】
Which of the following statements is NOT true?___
A. Getting off to work with a minimum effort helps save one's energy.
B. Dr. Kletman explains why people reach their peaks at different hours of day.
C. Habit helps a person adapt to his own energy cycle.
D. Children have energy cycles, too.
【单选题】
An effective way to prevent the burnout of young athletes is __________.___
A. to increase their sense of success
B. to make sports less competitive
C. to reduce their mental stress
D. to make sports more challenging
【单选题】
According to the passage sport is positive for young people in that __________.___
A. it can help them learn more about society
B. it enables them to find flaws in themselves
C. it teaches them how to set realistic goals for themselves
D. it can provide them with valuable experiences
【单选题】
Many coaches and parents are in the habit of criticizing young athletes __________.___
A. without realizing criticism may destroy their self-confidence
B. in order to make them remember life's lessons
C. believing that criticism is beneficial for their early development
D. so as to put more pressure on them
【单选题】
According to the passage parents and coaches should __________.___
A. help children to win every game
B. pay more attention to letting children enjoy sports
C. train children to cope with stress
D. enable children to understand the positive aspect of sports
【单选题】
The author's purpose in writing the passage is _________.___
A. to persuade young children not to worry about criticism
B. to stress the importance of positive reinforcement to children
C. to discuss the skill of combining criticism with encouragement
D. to teach young athletes how to avoid burnout
【单选题】
As pointed out at the beginning of the passage, people used to think that air pollution _______.___
A. cause widespread damage in the countryside
B. affected the entire eastern half of the United States
C. had damaged effect on health
D. existed merely in urban and industries areas
【单选题】
As to the greenhouse effect, the author ________.___
A. share the same view with the scientist
B. is uncertain of its occurrence
C. rejects it as being ungrounded
D. thinks that it will destroy the world soon
【单选题】
The underlined word "offset" in the second paragraph could be replaced by _________.___
A. slip into
B. make up for
C. set up
D. catch up with
【单选题】
It can be concluded that ____________.___
A. raising the world's temperature only a few degrees would not do much harm to life on earth
B. lowering the world's temperature merely a few degrees would lead major farming areas to disaster
C. almost no temperature variations have occurred over the past decade
D. the world's temperature will remain constant in the years to come
【单选题】
This passage is primarily about __________.___
A. the greenhouse effect
B. the burning of fossil fuels
C. the potential effect of air pollution
D. the likelihood of a new ice age
【单选题】
What is the major function of paragraph 1?___
A. To arouse the reader's concern.
B. To introduce the theme of the whole passage.
C. To summarize the whole passage.
D. To state the primary uses of TV.
