相关试题
【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
【单选题】
48分析运放的“虚断”是指是___。
A. U-≈U+
B. I-≈I+≈0
C. I-≈I+
D. U-≈U+≈0
【单选题】
51两级放大电路，Au1=-40，Au2=-50，若输入电压U1=5mv，则输出电压Uo为 ___
A. -200mv；
B. -250mV；
C. 10V；
D. 100V
【单选题】
52通用型集成运放的输入级多采用___。
A. 共基接法
B. 共集接法
C. 共射接法
D. 差分接法
【单选题】
53理想运放的两个重要性质是___。
A. 虚短与虚地
B. 虚断与虚短
C. 断路与短路
【单选题】
54振荡器的输出信号最初由___而来的。
A. 基本放大器
B. 选频网络
C. 干扰或噪声信号
【单选题】
55产生正弦波自激震荡的稳定条件是___。
A. 引入正反馈
B. |AF|≥1
C. AF=1
【单选题】
56从结构上来看，正弦振荡电路是一个 ___ 。
A. 有输入信号的负反馈放大器；
B. 没有输入信号的带选频网络的正反馈放大器；
C. 没有输入信号的不带选频网络的正反馈放大器。
【单选题】
57对频率稳定度要求较高的振荡器，要采用： ___ 。
A. LC振荡电路；
B. RC振荡电路；
C. RL振荡电路；
D. 石英晶体振荡电路。
【单选题】
58在甲类、乙类、甲乙类放大电路中，其导通角分别为___
A. 小于180 O、180 O、360O
B. 360O、180 O、小于180 O。
C. 180 O、小于180 O、360O
【单选题】
W78XX系和列W79XX系列引脚对应关系为 ___ 。
A. 一致；
B. 1脚与3脚对调，2脚不变；
C. 1、2对调。
【单选题】
60两个β相同的晶体管组成复合管后，其电流放大系数约为 ___ 。
【单选题】
1三极管的开关特性是___。
A. 截止相当于开关接通
B. 放大相当于开关接通
C. 饱和相当于开关接通
D. 截止相当于开关断开，饱和相当于开关接通
【单选题】
2数字集成门电路，目前生产最多应用最普遍的门电路是___
【单选题】
3由一个三极管组成的基本门电路是___。
【单选题】
4在遥测系统中，需通过___把非电量的变化转变为电信号。
A. 电阻器、
B. 电容器、
C. 传感器、
D. 晶体管
【单选题】
5半导体发光数码管由___个条状的发光二极管组成。
【单选题】
6“有0出1，全1出0”属于___
A. 与逻辑
B. 或逻辑
C. 非逻辑
D. 与非逻辑
【单选题】
7二进制数11101转化成十进制数为___
【单选题】
8TTL系列集成芯片工作电源电压的典型值是___。
A. 18V
B. 5V
C. 3V
D. 10V
【单选题】
10以下表达式中符合逻辑运算法则的是___。
A. 1+1=10
B. A+A=2A
C. A+=1.
D. A·=1
推荐试题
【单选题】
You shouldn't ______ your time like that, Bob, and was cold yesterdak tonight.
A. cut
B. do
C. kill
D. kick
【单选题】
Both the kids and their parents ____ English, I think. I know it from their accent.
A. is
B. been
C. are
D. was
【单选题】
You had better ___ a doctor as soon as possible.
A. seeing
B. saw
C. see
D. seen
【单选题】
He opened the letter and it contained ___.
A. an important information
B. some important informations
C. many important information
D. some important information
【单选题】
He has been writing for 3 years, but being a writer is not his ___.
A. chance
B. choice
C. change
D. character
【单选题】
They have never heard any ___.
A. a customer complaint
B. the customer's complaints
C. customer's complaint
D. the customers' complaints
【单选题】
He is not a child ___.
A. no more
B. no longer
C. any much
D. any more
【单选题】
The retired man is used to ___ his two dogs early in the morning.
A. exercise
B. exercising
C. exercised
D. exercises
【单选题】
It was not ___ midnight that they discovered the children were not in their bedroom.
A. before
B. at
C. after
D. until
【单选题】
Young ___ he is, he knows how to get along with others.
A. like
B. as
C. although
D. however
【单选题】
Could you show me where the___ shoes are?
A. Women
B. womens
C. woman
D. women's
【单选题】
He succeeded ___ out a lot of things entirely new in the world.
A. in working
B. to work
C. working
D. at working
【单选题】
It took me a long time to ___ the disappointment of failing the exam.
A. get over
B. get up
C. get into
D. get down
【单选题】
She ___ 100 pages of the book today.
A. has already read
B. already reads
C. already read
D. was already read
【单选题】
He has been ___ for nearly three weeks after the death of his dear pet.
A. sad
B. satisfied
C. evil
D. joyful
【单选题】
One cannot learn a foreign language well ___he studies hard.
A. unless
B. if
C. as
D. when
【单选题】
A large number of people___ present at the meeting, which was out of our expectation.
A. was
B. were
C. have
D. has
【单选题】
When the girls saw the funny man, they couldn't ___ laughing.
A. keep from
B. keep on
C. keep away
D. keep at
【单选题】
We are glad that we finally managed to get into contact ___ them.
A. at
B. on
C. from
D. with
【单选题】
This kind of plant___a lot of water at all times.
A. assumes
B. limits
C. produces
D. requires
【单选题】
Look! Here ___ the famous player.
A. comes
B. come
C. had come
D. coming
【单选题】
Uncle Sam sent him a___ bicycle as a birthday present.
A. red sports new
B. sports new red
C. new sports red
D. new red sports
【单选题】
I couldn't find my English-Chinese dictionary___.
A. anywhere
B. everywhere
C. nowhere
D. somewhere
【单选题】
The plane was about to___, and yet I left my ticket behind.
A. take off
B. take on
C. take up
D. take in
【单选题】
John succeeded ___ what he wanted.
A. to get
B. to getting
C. in getting
D. and getting
【单选题】
The accident was ___ to careless driving.
A. for
B. likely
C. due
D. because
【单选题】
With a good command of reading skills, most students can manage to read ___as they could the year before.
A. as twice fast
B. as fast as twice
C. as twice as fast
D. twice as fast
【单选题】
Some famous singers live on the ___from their record sales.
A. salary
B. price
C. bill
D. income
【单选题】
_____of them thinks that is a good idea.
A. Anyone
B. No one
C. None
D. Someone
【单选题】
Don't be too ___about things you're not supposed to know.
A. strange
B. amusing
C. curious
D. conscious
【单选题】
It was in 1969 ___the American astronauts succeeded in landing on the moon.
A. when
B. the moment
C. which
D. that
【单选题】
___people in the world are sending information by e-mail every day.
A. Several million
B. Many millions
C. Several millions
D. Many million
【单选题】
He___less time reading stories about film stars than before.
A. takes
B. spends
C. costs
D. pays
【单选题】
Selecting a mobile phone for personal use is no easy task because technology___so rapidly.
A. is changing
B. has been changed
C. will have changed
D. will change
【单选题】
The taxi driver always reminds passengers to ___their belongings when they leave the car.
A. keep
B. catch
C. hold
D. take
【单选题】
Little Tom is used to getting up ___eight every morning.
【单选题】
If the doctor had been available, the child _______.
A. would not die
B. could not have died
C. might not die
D. should not have died
【单选题】
If Mary___shopping this afternoon, please ask her to write a shopping list first.
A. will go
B. goes
C. went
D. has gone
【单选题】
These desks and chairs ___to the children in the mountain villages next week.
A. are sent
B. will send
C. have sent
D. will be sent
【单选题】
Every society has its own peculiar customs and ___of acting.
A. attitudes
B. behavior
C. ways
D. means
