【判断题】
因为变化的电流通过导体或线圈而产生自感电动势,自感电动势的大小和线圈形式及导线有关。
A. 对
B. 错
查看试卷,进入试卷练习
微信扫一扫,开始刷题
答案
A
解析
暂无解析
相关试题
【判断题】
晶体三极管有放大和截止两种工作状态。
A. 对
B. 错
【判断题】
电器的触头是各类接触器和继电器中的关键零件,电路的接通和断开都是依靠触头的接触和分离实现的。
A. 对
B. 错
【判断题】
电磁式发电机按励磁方式不同,又可分为他励、并励、串励及复励发电机。
A. 对
B. 错
【判断题】
使用万用表之前,要检查表针是否停在“0”位,否则应调整表盘下的调“0”螺钉。
A. 对
B. 错
【判断题】
万用表用毕后,应将“选择开关”拨到电阻挡位上,防止两笔短接消耗表内电池。
A. 对
B. 错
【判断题】
平波电抗器的作用主要是为了减少整流电流的脉动。
A. 对
B. 错
【判断题】
有动力附挂机车是根据调度命令附挂于列车回送的有动力机车
A. 对
B. 错
【判断题】
机车运转方式也叫机车运转制或机车周转方式,就是机车在交路上担当任务,往返行驶于机务段与折返(机务)段之间的运行方式。
A. 对
B. 错
【判断题】
循环式运转方式适用于电力、内燃机车。
A. 对
B. 错
【判断题】
机车技术速度是指机车牵引列车在区段内(不计入中间站停留时间)平均每小时走行的公里。
A. 对
B. 错
【判断题】
配属机车是指根据铁道部、铁路局配属命令拨交给铁路局、机务段保管、使用,涂有局、段标志并在资产台账内登记的机车。
A. 对
B. 错
【判断题】
机车交路按区段距离分为一般机车交路和长交路。
A. 对
B. 错
【判断题】
牵引总重吨公里是指机车牵引列车所完成的走行公里。
A. 对
B. 错
【判断题】
检查机车电气部分时,禁止手触各电器触头,不得带电检查处理故障或直接接触高压带电部件。
A. 对
B. 错
【判断题】
进行水阻试验或机车带负荷运行时,禁止进入高压室作业。
A. 对
B. 错
【判断题】
更换机车闸瓦作业中,严禁移动自阀或单阀手柄并挂好禁动牌。
A. 对
B. 错
【判断题】
更换闸瓦作业完毕后,应开放相应的制动缸塞门,然后撤除防溜措施。
A. 对
B. 错
【判断题】
进入机械间巡视检查前必须呼唤,经司机同意后方可进入。检查时,禁止接触各运动部件及高温或带电的部件,确保人身安全。
A. 对
B. 错
【判断题】
手触检查部件时,手背触及部件表面的持续时间为可以长时间手触,相应的温度为70℃平热上下。
A. 对
B. 错
【判断题】
使用试灯时要注意试灯有正灯、负灯之分。
A. 对
B. 错
【判断题】
正灯用于测试电器的正端电路故障,负灯用于测试电器的负端电路故障。
A. 对
B. 错
【判断题】
机车电器保养质量就是指电器的技术状态。
A. 对
B. 错
【判断题】
机车在运用中不准随意改变电器的动作整定值,禁止更改电器线路结构。
A. 对
B. 错
【判断题】
允许温升是由最高允许温度减去最高环境温度而得。
A. 对
B. 错
【判断题】
环火是指牵引电动机正负电刷之间被强烈的大电弧所短路。
A. 对
B. 错
【判断题】
牵引缓冲装置的用途是将机车与车辆连接或分离,在运行中传递牵引力,缓和及衰减牵引力与制动力的变化,具有连接、牵引和缓冲的作用。
A. 对
B. 错
【判断题】
在电机火化等级分类中的1级、1¼级 1½级均为持续运行中无害的火花。
A. 对
B. 错
【判断题】
在电刷的整个边缘有强烈的火花,同时有大火花飞出。换向器上严重发黑,用汽油不能擦掉,而且电刷有烧焦和损坏的3级火花是不允许运行的。
A. 对
B. 错
【判断题】
机车检查前必须遵守“先联系,后检查”的制度,并通知有关作业人员,在操纵手柄开关处挂好禁动标志。
A. 对
B. 错
【判断题】
对加封的零部件(如铅封、漆封)严禁随意破封,各种保护装置不得随意变动其动作参数。各部件检查完后,必须恢复定(原)位。
A. 对
B. 错
【判断题】
电力机车升弓做高压试验前,必须确认各高压室和地沟内无人后方可进行。高压试验升、降弓,必须按规定鸣笛和呼唤应答后方可进行,以保证人身安全。
A. 对
B. 错
【判断题】
牵引电动机半悬挂时,约有一半的质量支在车轴上,属于簧下质量;另一半支在构架上,属于簧上质量,所以称为半悬挂,也叫轴悬式。
A. 对
B. 错
【判断题】
动力制动:依靠机车的动力机械产生的制动力,包括电阻制动、再生制动、液力制动。
A. 对
B. 错
【判断题】
制动压力通过制动传动装置的传递,并增大后传给闸瓦,其增大的倍数称为制动倍率。
A. 对
B. 错
【判断题】
闸瓦压力大,制动力也大。但闸瓦压力不能过大,否则使机车、车辆易产生滑行。
A. 对
B. 错
【判断题】
防止空转和发生空转时处理办法之一是正在空转时,应立即降低牵引力,禁止撒砂。
A. 对
B. 错
【判断题】
挂车前适当撒砂,列车起动前适当压缩车钩可以防止空转。
A. 对
B. 错
【判断题】
机车运行中,由于弹簧的振动,动轴载荷产生不均和变化以及线路状态与线路坡道的大小等原因,均会致使机车粘着重量发生变化。
A. 对
B. 错
【判断题】
附加阻力是机车、车辆运行在某些特定条件下才能遇到的阻力。
A. 对
B. 错
【判断题】
列车在曲线上运行时的阻力大于相同条件下直线上的运行阻力。
A. 对
B. 错
推荐试题
【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
【单选题】
Older people are less likely to be ___ their negative emotions (情绪) and more likely to focus on the positive.
A. reserved for
B. caught up in
C. beat up to
D. counted on
【单选题】
I don’t have any bandage, so I have to ___ pressure to the wound to keep the bleeding down.
A. apply
B. involve
C. fulfill
D. establish
【单选题】
It is important that whichever candidate (候选人) is picked the loser should accept the defeat ___.
A. in advance
B. with great pride
C. with good grace
D. in large part
【单选题】
___ that new homes cost more than older homes, but that is not true across the country anymore.
A. It used to be
B. It is used to be
C. It used to being
D. It is used to being
【单选题】
The boss ___ his employees to work longer hours as the company is dreadfully short of staff at present.
A. called on
B. signed up
C. cared for
D. set up
【单选题】
The president’s visit and ___ discussions led to a plan that aimed to improve the trade relations between the two countries.
A. emerging
B. subsequent
C. consequent
D. Submerging
【单选题】
The author ___ his general idea mainly through statistics and results obtained from a survey (调查) about auto customer services in the United States.
A. assumes
B. engages
C. illustrates
D. represents
【单选题】
People in this town starved, several buildings were bombed and crime ___ because you had to steal to eat.
A. eroded
B. reflected
C. released
D. soared
【单选题】
Olympic recognition for bodybuilding (健美) remains ___ since some argue that bodybuilding is not a sport because the actual contest does not involve the same sort of efforts as “real” sports.
A. controversial
B. conventional
C. characteristic
D. influential
【单选题】
Tom tried to justify his absence from the meeting by ___ that he had been ill that day.
A. admitting
B. advocating
C. claiming
D. citing
【单选题】
___ the huge financial benefits, biological companies have been rushing to set up laboratories and new research projects.
A. Aware
B. Aware of
C. Not aware
D. Not aware of
【单选题】
Unfortunately, ___ lack of funds, the studies he began just two months ago, had to be ended early.
A. out of
B. in addition to
C. owing to
D. to begin with
【单选题】
With a good command of English, he soon got ___ to working with British people.
A. accustomed
B. consistent
C. relevant
D. responsible
【单选题】
What needs to be ___ here is that language and culture interact, and that understanding of one requires understanding of the other.
A. altered
B. stressed
C. aroused
D. committed
【单选题】
Policies and organizations must be created to meet workers’ hopes, and to ___ new problems that inevitably arise between workers and managers.
A. compromise
B. ensure
C. undermine
D. resolve
【单选题】
To keep the wheels of industry turning, we produce consumer goods in endless quantities, and, in the process, are rapidly ___ our natural resources.
A. ignoring
B. collapsing
C. enduring
D. exhausting
【单选题】
As a person who loves peace, he is committed ___ realizing peace between countries.
A. of
B. about
C. for
D. to
【单选题】
Learning how to use chopsticks is easy for me, ___ learning how to conduct myself at the table is quite difficult.
A. whereas
B. however
C. therefore
D. besides
【单选题】
___ that the patient smokes 50 cigarettes a day, it would be reasonable to assume there is some lung damage.
A. To give
B. Giving
C. Given
D. Having given
【单选题】
Kenyan (肯尼亚的) women tend to vote for those who could provide them ___ the necessary food to live on.
A. of
B. with
C. for
D. about
【单选题】
___ all obstacles and failures, the scientist continued doing his experiments day and night.
A. In spite of
B. In contrast to
C. As a matter of
D. As a result of
【单选题】
I’m willing to ___ that a larger car would have cost more, but I still think we should have bought one.
A. withdraw
B. indicate
C. abandon
D. concede
【单选题】
Manufacturing (制造) companies spend millions of pounds on advertisements, trying to ___ customers that their products are better than those of other companies.
A. confine
B. convince
C. depress
D. reconcile
【单选题】
He is not the right person for the project: he is not very technically minded and ___, he does not have the sense of responsibility.
A. instead
B. yet
C. furthermore
D. nevertheless
【单选题】
Death rates declined in many places, partly because of the ___ in hunger.
A. decrease
B. myth
C. obstacle
D. burden
【单选题】
In deciding whether or not a situation is safe, pilots must be taught to assume that the worst will happen, and then to ___ whether there is a risk or not.
A. absorb
B. apply
C. assess
D. occupy
【单选题】
The worker was not worried as he knew that if he gave up the job, there would be ___ opportunities for him to work somewhere else.
A. formative
B. marginal
C. vigorous
D. numerous
【单选题】
The research shows the region might ___ overheating (经济过热), but the policymakers so far appear to be relatively relaxed about the future of the economy.
A. catch a glimpse of
B. be at risk of
C. take a toll on
D. be free from
【单选题】
Measures have been taken to ensure that no student will have to ___ of college for economic reasons.
A. lay out
B. cancel out
C. drop out
D. stand out