相关试题
【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
【单选题】
11对于TTL与非门闲置输入端的处理，不可以___
A. 与有用输入端并联
B. 通过电阻3kΩ接电源
C. 接地
D. 接电源
【单选题】
12十线/四线优先编码器74LS147所用的输出代码为___。
A. 5421BCD码
B. 格雷码
C. 8421BCD码
D. 余3码
【单选题】
13为实现“线与”逻辑功能，应选用___
A. OC门
B. 与门
C. 异或门
D. 同或门
【单选题】
14和逻辑式A+ABC相等的式子是___
【单选题】
15逻辑函数的表示方法中具有唯一性的是___
A. 真值表
B. 表达式
C. 逻辑图
D. 卡诺图
【单选题】
16与模拟电路相比，数字电路主要的优点是___。
A. 容易设计
B. 通用性强
C. 抗干扰能力强
【单选题】
17某门电路的输入输出波形如图所示，试问此逻辑门的功能是___。
【单选题】
18以下电路中常用于总线应用的有___。
A. TSL门
B. OC门
C. 漏极开路门
D. CMOS与非门
【单选题】
逻辑表达式Y=AB可以用___实现。
A. 正或门
B. 正非门
C. 正与门
D. 负或门
【单选题】
20TTL电路在正逻辑系统中，以下各种输入中___相当于输入逻辑“0”。
A. 悬空
B. 通过电阻2.7kΩ接电源
C. 通过电阻2.7kΩ接地
D. 通过电阻510Ω接地
【单选题】
21对于TTL与非门闲置输入端的处理，不可以___。
A. 接电源
B. 通过电阻3kΩ接电源
C. 接地
D. 与有用输入端并联
【单选题】
22STTL数字集成电路与CMO数字集成电路相比突出的优点是___。
A. 微功耗
B. 高速度
C. 高抗干扰能力
D. 电源范围宽
【单选题】
23以下式子中正确的是___
A. 1+A＝A
B. A＋A=1
C. A•A＝1
D. A+AB=A
【单选题】
在一个四变量逻辑函数中，___为最小项。
【单选题】
A+BC=___。
A. A+B
B. A+C
C. （A+B）（A+C）
D. B+C
【单选题】
26以下代码中为无权码的为___。
A. 5421BCD码
B. 8421BCD码
C. 余三码
【单选题】
一位十六进制数可以用___位二进制数来表示。
【单选题】
28十进制数25用8421BCD码表示为___。4位
A. 10 101
B. 0010 0101
C. 100101
D. 10101
【单选题】
29与十进制数（53.5）10不等值的数或代码为___。
A. (0101 0011.0101)8421BCD
B. (35.8)16
C. (110101.1)2
D. (60.4)8
【单选题】
30与八进制数(47.3)8等值的数为___
A. (100111.011)2
B. (97.3)16
C. (27.3 )16
D. (100111.11)2
推荐试题
【单选题】
John Smith is _____ honest young man.___
【单选题】
She __________ in wearing that old – fashioned hat.___
A. insists
B. persists
C. assists
D. consists
【单选题】
Some of the meat came from Canada. How about________？___
A. another
B. the other
C. others
D. the rest
【单选题】
I have brought you ___ flowers for your birthday. ___
A. few
B. a few
C. little
D. a little
【单选题】
I have also experienced many adventures, but nothing that I have seen ___what you have described. ___
A. compares
B. relates
C. resembles
D. assembles
【单选题】
That young man has made so much noise that he ___ not have been allowed attend the concert. ___
A. could
B. must
C. would
D. should
【单选题】
“What is Mary doing at home?” “She is playing ____.”___
A. a piano
B. her piano
C. piano
D. the piano
【单选题】
I’m busy now ,ask him to see me ____ time.___
A. the other
B. some other
C. other
D. another
【单选题】
The child took a spoonful and tasted it carefully __________ it was hot.___
A. in case
B. provided
C. if
D. unless
【单选题】
The French pianist who had been praised very highly __________ to be a great disappointment. ___
A. turned off
B. turned up
C. turned out
D. turned down
【单选题】
“Shall I turn on the television?” – “No, I’d rather not __________ television tonight.”___
A. have watched
B. to watch
C. watch
D. for watching
【单选题】
They said that they had made up their minds to ____the task in spite of the extremely difficult conditions.___
A. carry on
B. carry off
C. carry away
D. carry forward
【单选题】
The two girls are getting on very well and share with each other. ___
A. little
B. much
C. some
D. none
【单选题】
The teacher said that the classroom was empty __________ a few chairs.___
A. but for
B. except for
C. apart from
D. besides
【单选题】
______you choose， make sure that it is a good one. ___
A. What
B. Wherever
C. Whichever
D. Which
【单选题】
Vingo was released from prison_____the successful efforts of his friends to prove his innocence. ___
A. according to
B. as a result of
C. for reasons of
D. with the help of
【单选题】
Entering the room， I found my father __ at the desk and ___ something .___
A. seat... write
B. seated ... wrote
C. seated ... writing
D. seating ... writing
【单选题】
Cake __________ of flour, sugar, egg and some other ingredients. ___
A. contained
B. consists
C. includes
D. composed
【单选题】
Mr. Peter wanted Steve to take half the money, but Steve did not __________ it. ___
A. obtain
B. achieve
C. accept
D. receive
【单选题】
I'd like to take my picture ________stands a high tower. ___
A. where
B. which
C. that
D. there
【单选题】
__________ the English examination I would have gone to the concert last Saturday. ___
A. But for
B. As for
C. In spite of
D. Because of
【单选题】
Cars moved very slowly in the 1920s, but they ______move more quickly than in 1910.___
A. were to can
B. did
C. will
D. can
【单选题】
The little girl needs __________ after her shock. ___
A. being comforted
B. be comforted
C. comforting
D. comforted
【单选题】
The __________ horse ran away from the fire.___
A. having frightened
B. frightening
C. frightened
D. frighten
【单选题】
He is __________ of an actor. ___
A. anybody
B. anything
C. somebody
D. something
【单选题】
You can take ______ seat you like. ___
A. no matter what
B. no matter which
C. what
D. whichever
【单选题】
He changed his name， _____ that nobody would find out what he had done before. ___
A. having thought
B. to think
C. thinks
D. thinking
【单选题】
----- _______is your English teacher？ ----- The one in red. ___
A. who
B. which
C. what
D. where
【单选题】
Can you give me a light for my cigarette? I have ____my matches.___
A. got out of
B. got rid of
C. got away with
D. run out of
【单选题】
Then the speaker __________ the various factors leading to the present economic crisis.___
A. went for
B. went after
C. went into
D. went on
【单选题】
I know Jonathan quite well and never doubt_____ he can do a good job of it___.
A. whether
B. that
C. when
D. what
【单选题】
I'm afraid it ______ tomorrow, but who knows?___
A. may have rained
B. might rain
C. would rain
D. ought to rain
【单选题】
He has spent ____money on his new house.___
A. a large number of
B. the number of
C. lots of
D. numbers of
【单选题】
This is the hotel __________ I like to stay.___
A. in which
B. at which
C. to which
D. at that
【单选题】
Would you mind keeping a（n）__________on the house for us while we are away？___
A. eye
B. /look
C. hand
D. view
【单选题】
He suggested the sports meet be _______because of the bad weather. ___
A. put away
B. put up
C. put down
D. put off
【单选题】
If the weather is __________ suitable, we will play the football match on Tuesday. ___
A. by means of
B. by any means
C. by no means
D. by all means
【单选题】
_____________is one of the five working languages at U.N. , which _______ are very proud of.___
A. The Chinese, the Chinese
B. Chinese language, Chinese
C. Chinese, the Chinese
D. Chinese language, the Chinese
【单选题】
The war lasted so long that people were tired of it. Everyday there was large crowds of demonstrators _____against the war.___
A. protecting
B. prescribing
C. protesting
D. prosecuting
【单选题】
Tom is so talkative. I’m sure you'll soon get tired ________ him.___
A. of
B. with
C. at
D. on
