【单选题】
开关接1时,电流表中流过的短路电流为___。
A. 0A
B. 0.2A
C. 10A
D. 约等于0.2A
查看试卷,进入试卷练习
微信扫一扫,开始刷题
答案
C
解析
暂无解析
相关试题
【单选题】
正弦交流电常用的表达方法有___。
A. 解析式表示法
B. 波形图表示法
C. 相量表示法
D. 以上都是
【单选题】
电感两端的电压相位超前电流___。
A. 90°
B. 180°
C. 360°
D. 30°
【单选题】
电容两端的电压相位滞后电流___。
A. 30°
B. 90°
C. 180°
D. 360°
【单选题】
应用戴维南定理求含源二端网络的输入等效电阻是将网络内各电动势___
A. 串联
B. 并联
C. 短接
D. 开路
【单选题】
LC 选频振荡电路,当电路频率等于谐振频率时,电路性质为___。
A. 电阻性
B. 感性
C. 容性
D. 纯电容性
【单选题】
阻值为4Ω的电阻和容抗为3Ω的电容串联,总复数阻抗为___
A. 3+j4
B. 3-j4
C. 4+j3
D. 4-j3
【单选题】
电动势为10V,内阻为2Ω的电压源变换成电流源时,电流源的电流和内阻是___
A. 10A,2Ω
B. 20A,2Ω
C. 5A,2Ω
D. 2A,5Ω
【单选题】
电流为5A,内阻为2Ω的电流源变换成一个电压源时,电压源的电动势和内阻为___
A. 10V,2Ω
B. 2.5V,2Ω
C. 0.4V,2Ω
D. 4V,2Ω
【单选题】
额定电压都为220V的40W、60W、100W三灯泡串联在220V的电源中,它们的发热量由大到小排列为___
A. 100W 60W 40W
B. 40W 60W 100W
C. 100W 40W 60W
D. 60W 100W 40W
【单选题】
在正弦交流电的解析式i=ImSin(ωt +φ)中,φ表示___
A. 频率
B. 相位
C. 初相位
D. 相位差
【单选题】
正弦交流电压u=100Sin(628t + 600)V,它的最大值为___。
A. 100 V
B. 100 V
C. 60V
D. 628 V
【单选题】
能表示容性电路电压与电流关系的相量图是___。
A.
B.
C.
D.
【单选题】
如图判断同名端为___
A. a与c
B. a与 d
C. b与c
【单选题】
电路中___定律指出:流入任意一节点的电流必定等于流出该节点的电流。
A. 欧姆
B. 基尔霍夫电流
C. 楞次
D. 基尔霍夫电压
【单选题】
已知电源电压为12 V ,四只相同灯泡的工作电压都是6 V,要使灯泡都能正常工作,则灯泡应___
A. 全部串联
B. 两只并联后与另两只串联
C. 两两串联后再并联
D. 全部并联
【单选题】
用戴维南定理分析电路“入端电阻”时,应将内部的电流源___处理。
A. 作开路
B. 作短路
C. 不进行
【单选题】
任何一个含源二端网络都可以用一个适当的理想电压源与一电阻___来代替。
A. 串联
B. 并联
C. 串联或并联
D. 随意联接
【单选题】
用交流电流表测得交流电流10A,则电路中电流的最大值为___。
A. 10A
B. 14.1A
C. 20A
D. 70.7A
【单选题】
如右图所示电路中,已知各支路的电流I1=I2=10A, 则电路的总电流I为___。
A. 20A
B. 0 A
C. 14.1A
D. 50A
【单选题】
1杂质半导体中多数载流子的浓度取决于___
A. 温度
B. 杂质浓度
C. 电子空穴对数目
【单选题】
2在电场作用下,空穴与自由电子运动形成的电流方向___
A. 相同
B. 相反
【单选题】
3光敏二极管应在___下工作
A. 正向电压
B. 反向电压
【单选题】
4下列半导体材料哪一种的热敏性突出“导电性受温度影响最大”?___
A. 本征半导体
B. N型半导体质
C. P型半导体
【单选题】
5用万用表电阻挡检测某一个二极管时,发现其正、反电阻均近于1000KΩ,这说明该二极管是属于___。
A. 短路状态;
B. 完好状态;
C. 断路状态;
D. 极性搞错。
【单选题】
6稳压二极管是一个可逆击穿二极管,稳压时工作在___状态。
A. 正偏
B. 反偏 E、正向导通 F、截止
【单选题】
7三端集成稳压器CW7812的输出电压是___。
A. 12V
B. 5V
C. 9V
【单选题】
8三端集成稳压器CXX7805的输出电压是___
A. 5v
B. 9v
C. 12v
【单选题】
9一个平衡PN结,用导线将P区和N区连起来,而导线中___。
A. 有微弱电流
B. 无电流
C. 有瞬间微弱电流
【单选题】
10二极管两端正向电压大于___电压时,二极管才导通。
A. 击穿电压;
B. 死区;
C. 饱和。
【单选题】
11当温度升高时,二极管的反向饱和电流 ___ 。
A. 增大;
B. 减小;
C. 不变;
D. 无法判定。
【单选题】
12硅二极管的正向导通压降比锗二极管的___ 。
A. 大
B. 小
C. 相等
【单选题】
13三端集成稳压器 CW7906的输出电压是___
A. -12v
B. -9v
C. -6V
【单选题】
14稳压管的工作是利用伏安特性中的___。
A. 正向特性
B. 反向特性
C. 反向击穿特性
【单选题】
15二极管具有___
A. 正向特性
B. 反向特性
C. 单向导电特性
D. 反向击穿特性
【单选题】
16图中D1-D3为理想二极管,A,B,C灯都相同,试问___灯最亮。
A. A灯
B. B灯
C. C灯
【单选题】
18在单相桥式整流电容滤波电路中,设U2为其输入电压,输出电压的平均值约为___。
A. U0=0.45U2
B. U0=1.2U2
C. U0=0.9U2
D. U0=1.4U2
【单选题】
19在单相桥式整流电路中,设U2为其输入电压,输出电压的平均值约为___。
A. U0=0.45U2
B. U0=1.2U2
C. U0=0.9U2
D. U0=1.4U2
【单选题】
20在半波整流电容滤波电路中,设U2为其输入电压,输出电压的平均值约为___。
A. U0=0.45U2
B. U0=1.2U2
C. U0=0.9U2
D. U0=1.4U2
【单选题】
21在半波整流电路中,设U2为其输入电压,输出电压的平均值约为___。
A. U0=0.45U2
B. U0=1.2U2
C. U0=0.9U2
D. U0=1.4U2
【单选题】
22温度影响了放大电路中的___,从而使静态工作点不稳定。
A. 电阻;
B. 电容;
C. 三极管;
D. 电源。
推荐试题
【填空题】
advocate,involve,confine,respond,subsequent ,distinct ,intense, fulfill,circumstance, reconcile The duties to provide services for children in need are not [ ] to the local social services department
【填空题】
advocate,involve,confine,respond,subsequent ,distinct ,intense, fulfill,circumstance, reconcile We pray that all nations be [ ] and that all people around the world live in peace
【填空题】
controversial,assess, resolve,decrease,alter,abandon,indicate,undermine,compromise, conventional It was reported the president had [ ]to fight If war was necessary,even if it meant destroying his chances of re-election
【填空题】
controversial,assess, resolve,decrease,alter,abandon,indicate,undermine,compromise, conventional I had to [ ] one of my email accounts as it was filled with junk mail
【填空题】
controversial,assess, resolve,decrease,alter,abandon,indicate,undermine,compromise, conventional Darwin's theory of evolution remains[ ] partly because it challenges the religious belief that God created man
【填空题】
advocate,involve,confine,respond,subsequent ,distinct ,intense, fulfill,circumstance, reconcile He suggested a small but [ ] improvement on our former plan; I really appreciate it.
【填空题】
in sb. 's words,count on,make sense of ,reserve for, shield from,call on, sum up, relate to ,in need, be/ get caught up in She held her hand above her eyes to [ ]them [ ] the sun so that she could see more clearly the man in front of her
【填空题】
in sb. 's words,count on,make sense of ,reserve for, shield from,call on, sum up, relate to ,in need, be/ get caught up in The boy studied the signs for over an hour,but still could not [ ]them, so he turned to his teacher for help
【填空题】
in sb. 's words,count on,make sense of ,reserve for, shield from,call on, sum up, relate to ,in need, be/ get caught up in They [ ] the developed countries to commit more money to protecting the environment
【填空题】
in sb. 's words,count on,make sense of ,reserve for, shield from,call on, sum up, relate to ,in need, be/ get caught up in We will continue to care for those [ ] and work to establish a society that is generous and prosperous
【填空题】
in sb. 's words,count on,make sense of ,reserve for, shield from,call on, sum up, relate to ,in need, be/ get caught up in Many people [ ]careers and raising kids so that they forget that their marriages also need to be taken good care of
【填空题】
in sb. 's words,count on,make sense of ,reserve for, shield from,call on, sum up, relate to ,in need, be/ get caught up in My most favorite program is the one that deals with scientific subjects that ordinary people can [ ]
【填空题】
in sb. 's words,count on,make sense of ,reserve for, shield from,call on, sum up, relate to ,in need, be/ get caught up in Finally, I would like to [ ]by saying that it has been a tremendous pleasure to work with you all
【填空题】
in sb. 's words,count on,make sense of ,reserve for, shield from,call on, sum up, relate to ,in need, be/ get caught up in He is a person that you always [ ]when you need help.
【填空题】
in sb. 's words,count on,make sense of ,reserve for, shield from,call on, sum up, relate to ,in need, be/ get caught up in This restaurant is very popular because it has some separate, smaller rooms [ ] families with small children
【填空题】
in sb. 's words,count on,make sense of ,reserve for, shield from,call on, sum up, relate to ,in need, be/ get caught up in Betty loves reading.[ ],“Reading is the most wonderful thing in the world.”
【填空题】
open the door to,In advance,all at once,reap the benefits (of), make the most of,over time, get by, stand a chance (of),remind of, take pleasure in, Every one of you has made a contribution and I [ ] knowledging what each of you has done to make this academic convention such a success.
【填空题】
open the door to,In advance,all at once,reap the benefits (of), make the most of,over time, get by, stand a chance (of),remind of, take pleasure in They all tried to talk [ ], but I couldn't hear anything they said
【填空题】
open the door to,In advance,all at once,reap the benefits (of), make the most of,over time, get by, stand a chance (of),remind of, take pleasure in, Yellow flowers in the field always [ ] me [ ] my childhood in the countryside
【填空题】
open the door to,In advance,all at once,reap the benefits (of), make the most of,over time, get by, stand a chance (of),remind of, take pleasure in, We have been practicing for so long and so hard that our team should [ ]winning the game
【填空题】
open the door to,In advance,all at once,reap the benefits (of), make the most of,over time, get by, stand a chance (of),remind of, take pleasure in, Research on genes will [ ] exciting new medical treatments.,
【填空题】
open the door to,In advance,all at once,reap the benefits (of), make the most of,over time, get by, stand a chance (of),remind of, take pleasure in, My family [ ] on my father's unemployment benefit after he lost his job
【填空题】
open the door to,In advance,all at once,reap the benefits (of), make the most of,over time, get by, stand a chance (of),remind of, take pleasure in, Many subway riders read books or listent music in order to [ ] their time on the way to work
【填空题】
open the door to,In advance,all at once,reap the benefits (of), make the most of,over time, get by, stand a chance (of),remind of, take pleasure in, In order to make sure he would be able to attend the meeting, I called him up two weeks [ ]
【填空题】
open the door to,In advance,all at once,reap the benefits (of), make the most of,over time, get by, stand a chance (of),remind of, take pleasure in, In order to [ ]physical exercise, you have to exercise regularly and for at least half an hour each time
【填空题】
embarrass,polish, emotional, etticiency,curb ,await, donation ,dump,stuff ,historical Mary was a careful speaker, every word seemed to have been [ ] before it was allowed to escape through her lips
【填空题】
embarrass,polish, emotional, etticiency,curb ,await, donation ,dump,stuff ,historical He has a special feeling for the brilliant birds, and each spring he eagerly [ ] their return
【填空题】
embarrass,polish, emotional, etticiency,curb ,await, donation ,dump,stuff ,historical Thanks to the [ ] of air transport,everyone is free to go anywhere at any time
【填空题】
embarrass,polish, emotional, etticiency,curb ,await, donation ,dump,stuff ,historical John believes that the [ ] of food to the hungry is more helpful than giving money
【填空题】
embarrass,polish, emotional, etticiency,curb ,await, donation ,dump,stuff ,historical When she heard it was snowing in the city they were going to, she [ ] two more sweaters into her bag.
【填空题】
embarrass,polish, emotional, etticiency,curb ,await, donation ,dump,stuff ,historical During our stay in Europe we visited many places of [ ] interest, including several castles
【填空题】
embarrass,polish, emotional, etticiency,curb ,await, donation ,dump,stuff ,historical The wedding ceremony of my sister was a very [ ] experience for our family
【填空题】
embarrass,polish, emotional, etticiency,curb ,await, donation ,dump,stuff ,historical He was [ ]when he discovered that he didn't have enough money to pay for the red wine he had ordered
【填空题】
embarrass,polish, emotional, etticiency,curb ,await, donation ,dump,stuff ,historical The local government is pressed to find new places to [ ] dump waste
【填空题】
embarrass,polish, emotional, etticiency,curb ,await, donation ,dump,stuff ,historical The new system designed to [ ] harmful emissions排放物) from factories will be put into use soon
【填空题】
explore ,transmit, resource, emerge,yield, pose, assume, confidence,inherit, comprehensive It is so difficult to [ ] the bottom of the ocean because some parts are very deep.
【填空题】
explore ,transmit, resource, emerge,yield, pose, assume, confidence,inherit, comprehensive It was about 30 seconds before Alex [ ] from the water, we were quite scared
【填空题】
explore ,transmit, resource, emerge,yield, pose, assume, confidence,inherit, comprehensive We often [ ] that when other people do the same things as we do, they do them,for the same reasons; but this assumption is not always reasonable
【填空题】
explore ,transmit, resource, emerge,yield, pose, assume, confidence,inherit, comprehensive There is widespread concern that the rising unemployment may [ ] a threat to social stability.
【填空题】
explore ,transmit, resource, emerge,yield, pose, assume, confidence,inherit, comprehensive After a(n) [ ] physical exam, my doctor said I was in good condition except that my blood pressure was a little high