相关试题
【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。
【单选题】
7三端集成稳压器CW7812的输出电压是___。
【单选题】
8三端集成稳压器CXX7805的输出电压是___
【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。
【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___ 。
【单选题】
13三端集成稳压器 CW7906的输出电压是___
【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。
【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。
【单选题】
23用直流电压表测得放大电路中某三极管各极电位分别是2V、6V、2.7V，则三个电极分别是___。
A. [B、C、E]
B. [C、B、E]
C. [E、C、B]
【单选题】
24共射极放大电路的交流输出波形上半周失真时为___
【单选题】
25三极管的反向电流ICBO是由___组成的。
A. 多数载流子
B. 少数载流子
C. 多数载流子和少数载流子
【单选题】
27如果在NPN型三极管放大电路中测得发射结为正向偏置，集电结也为正向偏置，则此管的工作状态为___
A. 放大状态；
B. 截止状态；
C. 饱和状态；
D. 不能确定。
【单选题】
28在以下三种电路中输入电阻最大的电路是___。
A. 共基放大电路
B. 共集放大电路
C. 共射放大电路
【单选题】
29在以下三种电路中既能放大电流，又能放大电压的电路是___。
A. 共基放大电路
B. 共集放大电路
C. 共射放大电路
【单选题】
30在以下三种电路中输出电阻最小的电路是___；
A. 共基放大电路
B. 共集放大电路
C. 共射放大电路
【单选题】
当PNP型晶体管工作在放大区时，各极电位关系为uC ___uB。
【单选题】
32当PNP型晶体管工作在放大区时，各极电位关系为uB___uE 。
【单选题】
33测得NPN型三极管上各电极对地电位分别为，，，说明此三极管处在___。
A. 放大区
B. 饱和区
C. 截止区
D. 反向击穿区
【单选题】
34若使三极管具有电流放大能力，必须满足的外部条件是___。
A. 发射结正偏、集电结正偏
B. 发射结反偏、集电结反偏
C. 发射结正偏、集电结反偏
D. 发射结反偏、集电结正偏
【单选题】
35在由PNP晶体管组成的基本共射放大电路中，当输入信号为1KHz、5mV的正弦电压时，输出电压波形出现了顶部削平的失真。这种失真是___ 。
A. 饱和失真
B. 截止失真
C. 交越失真
D. 频率失真
【单选题】
36在由PNP晶体管组成的基本共射放大电路中，当输入信号为1KHz、5mV的正弦电压时，输出电压波形出现了底部削平的失真。这种失真是___ 。
A. 饱和失真
B. 截止失真
C. 交越失真
D. 频率失真
【单选题】
37共集电极放大电路中Re的负反馈组态是___。
A. 电压串联负反馈
B. 电流串联负反馈
C. 电压并联负反馈
【单选题】
38为了使放大器带负载能力强，一般引入___负反馈。
【单选题】
41为了提高三极管放大电路的输入电阻，采用___负反馈 i=i1+i2
【单选题】
42为了稳定输出电流，采用___负反馈。
【单选题】
43为了改善放大器的动态性能，应该引入___电路。
A. 直流负反馈
B. 交流负反馈
C. 电压负反馈
D. 电流负反馈
【单选题】
44为了稳定放大器的静态工作点，应该引入___电路。
A. 直流负反馈
B. 交流负反馈
C. 电压负反馈
D. 电流负反馈
【单选题】
45共模抑制比是差分放大电路的一个主要技术指标，它反映放大电路___能力。
A. 放大差模抑制共模
B. 输入电阻高
C. 输出电阻低
【单选题】
46差分放大电路是为了___而设置的。
A. 稳定Au
B. 放大信号
C. 抑制零点漂移
【单选题】
47分析运放的“虚短”是指是___。
A. U-≈U+
B. I-≈I+≈0
C. U0=Ui
D. U-≈U+≈0
推荐试题
【填空题】
9.The police are investigating the three men allegedly _________organizing and carrying out the bank robbery.
【填空题】
10.I do not doubt in the least that inflation leads to _________decline.
【填空题】
11.A blizzard _______________great drifts of snow across the lake.
【填空题】
12.Tim says _________everybody will be affected by the tax increase, but I’m sure he’s exaggerating.
【填空题】
1.China’s economic success over the past three _________has raised the living standards of hundreds of millions of Chinese citizens.
【填空题】
2.Citibank picked the chief executive of Etang.com as its first Chinese customer Thursday to open an account at its new branch in the _______Pease Hotel along Shanghai’s fabled waterfront.
【填空题】
3.The United States last Wednesday _________tariffs关税 of up to 30 percent on a range of foreign steel imports to help protect its domestic国内的industry.
【填空题】
4.Although he was raised as a Christian, he’s not really very _________.
【填空题】
5.You can distinguish between frogs ands toads蟾蜍 in the following way: frogs have _________bodies, long limbs, and a smooth skin, and toads have stouter bodies, short limbs, and dry skin.
【填空题】
6.From the airplane window I could see a _________of city streets.
【填空题】
7.Aunt Pat smiled at her little niece and _________her to eat.
【填空题】
8.Dr. Rich Hamilton is planning his own World Wide Web _________on the Internet to provide assistance to anyone who asks for medical help.
【填空题】
9.It is difficult to estimate the number of people doing part-time jobs _________
【填空题】
10.The president _________his foreign minister, Mr. Burns, to act as representative to the international conference to be held in Tokyo next month.
【填空题】
11.Advances in telecommunications have meant that it is just as easy to work from a computer _________at home as it is from a town center office.
【填空题】
12.Until the new gym is built, you have no option but _________existing buildings which may or may not suit your immediate目前的requirements.
【填空题】
1.According to some scientists, global warming _________the survival of the whole human race.
【填空题】
2.The number of visitors from parts of Scotland not including the Edinburgh area was, in fact, relatively small19%, and exceeded the number of overseas visitors16%_________.
【填空题】
3.The early Spaniards established a chain of mission _________the local population along the San Antonio River.
【填空题】
4.It was common practice then that when the store owners wanted to go on vacation they simply _________
【填空题】
5.As they didn’t have relatives or friends there they often _________around nearby malls when they got bored.
【填空题】
6.To make a birthday card, you can simply cut out some funny or pretty pictures from magazines, _________them _________a piece of card and then write your message inside.
【填空题】
7.She picked up the receiver and, _________ asking the caller to hold on, went off to tell Jack that he was wanted on the phone.
【填空题】
8.To relax himself for a little while, he rose from the computer desk, walked across the room towards the window and stretched both arms upwards and _________.
【填空题】
9.The new product has a pair of small loudspeakers fitted inside, which you can easily _________ your computer’s sound card.
【填空题】
10.Music in fact is a _________language of a non-verbal nature which is rich in expression.
【填空题】
11.This _________is designed to show at a glance how many rooms have been rented out and how many are still available.
【填空题】
12._________ glorious sunshine, the boundless stretch of corn fields looked an impressive sight.
【填空题】
1.The cook put the meat on a plate, _________it with salt and pepper, wrapped up the plate in aluminum foil铝箔 and then placed it in the oven to roast.
【填空题】
2.Every waking moment we talk to ourselves about the things we experience. Our self-talk, the thought we communicate to ourselves, _________control the way we feel and act.
【填空题】
3.John made everyone laugh when he got the words _________and referred to himself as “my husband’s wife”.
【填空题】
4.You can’t live a perfect day without doing something for someone who will perhaps never be able to _________you.
【填空题】
5.Because the Earth is a sphere, sailors _________only can view other ships to a distance of about 13 miles before those ships seem to disappear into the horizon.
【填空题】
6.Johnson dismissed _________ideas lightly as no good on several occasions.
【填空题】
7.One tends to believe whatever one repeats to oneself sufficiently often, whether the _________be true or false.
【填空题】
8.Susan told me numerous times how her sister _________children.
【填空题】
9.I don’t know what my roommate is up to because he does everything _______________, either when I am away or when I am asleep.
【填空题】
10.For economic reasons, shipbuilders have designed vessels___ that can be loaded and _________in a minimum amount of time with minimum labor.
【填空题】
11.Laugh, and the world laughs with you; _________, and you weep alone.
【填空题】
12.A national debate is now _________about the manner in which we as a society should protect our natural resources.
