相关试题
【单选题】
36在12MHz的8×51系统里，哪一种方式一次可定时5ms？___
A. Mode 0及Mode 1
B. Mode 1及Mode 2
C. Mode 2及Mode 3
D. Mode3及Mode 1
【单选题】
37若要让Timer作为外部计数只用，应如何设置？___
A. Gate=0
B. Gate=1
C. C/=0
D. C/=1
【单选题】
39下列哪个不是8×51所提供的省电方式？___
A. PD方式
B. IDL方式
C. LP方式
D. 待机方式
【单选题】
89S51的看门狗有何作用？___
A. 重复执行程序
B. 找回遗失数据
C. 复位系统
D. 防止中毒
【单选题】
41若要启用WDT，则应依次填入WDTRST寄存器哪些数据？___
A. 0xe1、0xe2
B. 0xe1、0x1e
C. 0x1e、0xe1
D. 0x10、0x01
【单选题】
8×51的定时器，在下列哪种方式下具有自动加载功能？___
A. Mode0
B. Mode1
C. Mode2
D. Mode3
【单选题】
45下列哪种AD转换器的转换速度比较快？___
A. 双斜率型AD转换器
B. 比较型AD转换器
C. 连续计数式AD转换器
D. 逐渐接近式AD转换器
【单选题】
46下列哪种AD转换器的精密度比较高？___
A. 双斜率型AD转换器
B. 比较型AD转换器
C. 连续计数式AD转换器
D. 逐步逼近式AD转换器
【单选题】
47对于8×8 LED点阵而言，其中的LED个数及引脚各为多少？___
A. 64、16
B. 16、16
C. 64、12
D. 32、12
【单选题】
48在共阳极型8×8 LED点阵里，其阳极如何连接？___
A. 各行阳极连接到行引脚
B. 各列阳极连接到列引脚
C. 各行阳极连接到列引脚
D. 各列阳极连接到行引脚
【单选题】
49在共阳极型8×8 LED点阵里，其阴极如何连接？___
A. 各行阴极连接到行引脚
B. 各列阴极连接到列引脚
C. 各行阴极连接到列引脚
D. 各列阴极连接到行引脚
【单选题】
50双色8×8 LED点阵的列引脚与行引脚各位多少？___
A. 12、12
B. 8、16
C. 16、8
D. 24、8
【单选题】
___的方向规定由高电位点指向低电位点。
【单选题】
三相电动势到达最大的顺序是不同的，这种达到最大值的先后次序，称三相电源的相序，相序为U-V-W-U，称为___。
【单选题】
电路的作用是实现能量的传输和转换、信号的___和处理。
【单选题】
电阻器反映导体对电流起阻碍作用的大小，简称___。
A. 电动势
B. 功率
C. 电阻率
D. 电阻
【单选题】
___反映了在不含电源的一段电路中，电流与这段电路两端的电压及电阻的关系。
A. 欧姆定律
B. 楞次定律
C. 部分电路欧姆定律
D. 全欧姆定律
【单选题】
并联电路中的总电流等于各电阻中的___。
A. 倒数之和
B. 相等
C. 电流之和
D. 分配的电流与各电阻值成正比
【单选题】
串联电路中流过每个电阻的电流都___。
A. 电流之和
B. 相等
C. 等于各电阻流过的电流之和
D. 分配的电流与各电阻值成正比
【单选题】
___的一端连在电路中的一点，另一端也同时连在另一点，使每个电阻两端都承受相同的电压，这种联结方式叫电阻的并联。
A. 两个相同电阻
B. 一大一小电阻
C. 几个相同大小的电阻
D. 几个电阻
【单选题】
___的电阻首尾依次相连，中间无分支的联结方式叫电阻的串联。
A. 两个或两个以上
B. 两个
C. 两个以上
D. 一个或一个以上
【单选题】
电流流过负载时，负载将电能转换成___。
A. 机械能
B. 热能
C. 光能
D. 其他形式的能
【单选题】
电功的数学表达式不正确的是___。
A. W=Ut/R2t
B. W=UIt
C. W=U2t/Rt
D. W=I2Rt
【单选题】
测量电压时，电压表应与被测电路___。
【单选题】
测量电流时,万用表的接线方法与直流电流表一样，应把万用表___在电路中。测量直流电压时，应把万用表与被测电路并联。
【单选题】
串联电路中各电阻两端电压的关系是___。
A. 各电阻两端电压相等
B. 阻值越小两端电压越高
C. 阻值越大两端电压越高
【单选题】
确定正弦量的三要素为 ___。
A. 相位、初相位、相位差
B. 最大值、频率、初相角
C. 周期、频率、角频率
【单选题】
当电压为5V时,导体的电阻值为5欧,那么当电阻两端电压为2V时,电阻值为___欧。
【单选题】
对称负载接成星形时,三相总电流___。
A. 等于零
B. 等于其中一相电流的三倍
C. 等于其中一相电流。
【单选题】
一段有源支路如图1所示，AB两端的电压UAB为___。
A. 10 V
B. —2V
C. 2V
D. —10V
【单选题】
如图2电路中，等效电阻=___
A. 150Ω
B. 900Ω
C. 600Ω
D. 100Ω
【单选题】
电流表的读数是4A，则电路中电流表的读数是 ___
【单选题】
在R、L、C串联电路中，已知＝3Ω，＝5Ω，＝8Ω，则电路的性质为 ___。
A. 感性
B. 容性
C. 阻性
D. 不能确定
【单选题】
工业生产中大量的设备均为感性负载，功率因数往往很低，常采取___的方法来提高电网的功率因数。
A. 并联电容
B. 串联电容
C. 串联电感
D. 并联电感
【单选题】
交流电压表及电流表指示的数值是___
A. 平均值
B. 有效值
C. 最大值
D. 瞬时值
【单选题】
RLC串联电路发生谐振，，R=10Ω，Ω，则谐振时的感抗为___
A. 10Ω
B. 40Ω
C. 20Ω
D. 30Ω
【单选题】
RL从电路获得最大功率，此时RL=___。
【单选题】
使用电解电容时___。
A. 负极接高电位，正极接低电位
B. 正极接高电位，负极接低电位
C. 正极接高电位，负极也可以接高电位
D. 不分正负极
推荐试题
【判断题】
现金流量表的分析填列法是直接根据资产负债表、利润表和有关会计科目明细账的记录分析计算出现金流量表各个项目的金额，据此编制现金流量表的方法
【判断题】
为了清晰反映构成所有者权益各组成部分当期的增减变动情况，所有者权益变动表采用矩阵形式列示
【判断题】
销售净利率是20%，资产周转率是1次，权益乘数是2，则净资产收益率是40%
【判断题】
一般认为，资本保值率越高，表明企业的资本保全状况越好，所有者权益增长越快，债权人的债务越有保障
【判断题】
如果企业的负债资金的利息率低于其资产报酬率，则提高资产负债率可以增加所有者权益报酬率
【判断题】
杜邦分析体系是利用各主要财务比率之间的内在联系，综合分析企业财务状况的方法。建立财务分析指标体系
【判断题】
沃尔比重评分法是将选定的财务比率用线性关系联系起来，并分别给定各自的分数比重，然后通过与标准比重进行比较，确定各项指标的得分及总体指标的累积分数，从而对企业的信用水平做出评价的方法
【填空题】
boost prospect calculate accelerate promote
mystery destruction analysis insight barrier
1 In our class,most discussions and activities take place in assigned small groups,These groups provide a supportive and safe environment that （） learning
【填空题】
commence,deserve,tempting, coordinate,
lodge,confess, grant, proceed ,display, consequently
9 As the finance ministry rejected the defor its "lack of clarity",it[ ]complaint with the Europear Commission that this deal was against the law
【填空题】
commence,deserve,tempting, coordinate,
lodge,confess, grant, proceed ,display, consequently
5 State governments and the colleges themselves have [ ] financial help to students with special abilities and those with financial needs
【填空题】
commence,deserve,tempting, coordinate,
lodge,confess, grant, proceed ,display, consequently
10 Dogs cannot distinguish the color of trafficlights, so the master must make the decision of when it is safe to [ ] across the road
【填空题】
commence,deserve,tempting, coordinate,
lodge,confess, grant, proceed ,display, consequently
6 The committee agreed that his papers
[ ] a wider circulation because of their essential and fundamental interest to a larger audience.
【填空题】
prepare for , be bound to , stand up for , in favor of ,speculate about , in the company of, in the form of , be liable to , invest..with , in succession
1 Because women often restrict their diet
In an effort to control weight,they may
Not consume enough iron-rich food and
( ) experience an iron Deficiency.
【填空题】
commence,deserve,tempting, coordinate,
lodge,confess, grant, proceed ,display, consequently
8 Americans defend the right to obtain a gun and they have[ ] been willing to turn a blind eye to the harm that people owning guns have caused
【填空题】
commence,deserve,tempting, coordinate,
lodge,confess, grant, proceed ,display, consequently
7 The anger and frustration [ ] by the local people who do not understand what is happening to them will be a terrible and dangerous force
【填空题】
prepare for , be bound to , stand up for , in favor of ,speculate about , in the company of, in the form of , be liable to , invest..with , in succession
2 Some reform advocates ignore the impact of
Class size on student achievement,and they
are ( ) what they call as a Priority:teacher effectiveness.
【填空题】
prepare for , be bound to , stand up for , in favor of ,speculate about , in the company of, in the form of , be liable to , invest..with , in succession
3 Because of easy access to the Internet,the
New breakthrough tq create something
Truly creative ( ) happen anytime now.
【填空题】
prepare for , be bound to , stand up for , in favor of ,speculate about , in the company of, in the form of , be liable to , invest..with , in succession
4 Indeed,if teachers want to( ) how far students might get in life, a better measurement than grades might be how hard the students try.
【填空题】
prepare for , be bound to , stand up for , in favor of ,speculate about , in the company of, in the form of , be liable to , invest..with , in succession
5 Nature has( ) these animals ( ) a capacity for not showing Fear.
【填空题】
prepare for , be bound to , stand up for , in favor of ,speculate about , in the company of, in the form of , be liable to , invest..with , in succession
6 During the weeks of discussion,delegations
from groups who are interested in the
Resolution may call on representatives to
( ) their point of view.
【填空题】
prepare for , be bound to , stand up for , in favor of ,speculate about , in the company of, in the form of , be liable to , invest..with , in succession
7 Plato was a superb writer,and his works are
Part of the world’s great literature.Most of
His existing work is ( )Dialogs and letters.
【填空题】
prepare for , be bound to , stand up for , in favor of ,speculate about , in the company of, in the form of , be liable to , invest..with , in succession
8 Young people should enter into a broad
Flexible training program,through which
They can learn a lot and be ( ) their future careers.
【填空题】
prepare for , be bound to , stand up for , in favor of ,speculate about , in the company of, in the form of , be liable to , invest..with , in succession
9 The young man is very happy and proud to
be ( ) the old professor because he always feeIs great when talking With him.
【填空题】
prepare for , be bound to , stand up for , in favor of ,speculate about , in the company of, in the form of , be liable to , invest..with , in succession
10 One day they passed more than 20 villages ( ),and some of these are Said to have stretched for six miles or more.
【填空题】
boost prospect calculate accelerate promote
mystery destruction analysis insight barrier
7 Being asingle parent,there is no way for her
to ( ) the time and energy she has
devoted to her children for the past 10 years.
【填空题】
boost prospect calculate accelerate promote
mystery destruction analysis insight barrier
8 It is essential that you start by listening because one of the main ( ) teenagers and their parents face in forming positive relationships is that neither listens to the other.
【填空题】
boost prospect calculate accelerate promote
mystery destruction analysis insight barrier
9 We all know the dangers of an earthquake: the ( ) to buildings,the troubles can be caused by falling trees,and the terror occurs when the earth actually opens uip.
【填空题】
boost prospect calculate accelerate promote
mystery destruction analysis insight barrier
10 Not until recently have we realized that the increasing world population may lead to a potential gloomy ( ) for humanity starvation.
【填空题】
boost prospect calculate accelerate promote
mystery destruction analysis insight barrier
2 It is the development strategy/of the company to ( ) its overseas expansion in order to take a slice of the world market
【填空题】
boost prospect calculate accelerate promote
mystery destruction analysis insight barrier
3 Nearly six million people go to see the Mona
Lisa every year,attracted by the ( )of her smile.When you're not lodking at her, she seems to be smiling;when you look at her,she stops.
【填空题】
Boost prospect calculate accelerate promote
mystery destruction analysis insight barrier
4 To live with a family whose native language is English is the ideal way to further improve one's English and to gain ( )into its culture.
【填空题】
Boost prospect calculate accelerate promote
mystery destruction analysis insight barrier
5 There is a real need to ( ) academic
achievement in schools and help with the
development of a student's overall character.
【填空题】
boost prospect calculate accelerate promote
mystery destruction analysis insight barrier
6 Einstein said his scientific discoveries grew
from his imagination rather than from( ),
reason and language.
【填空题】
commence,deserve,tempting, coordinate,
lodge,confess, grant, proceed ,display, consequently
1 When the police caught up with him, Mr.Foster had to [ ] that he'd broken the speed limit.
【填空题】
commence,deserve,tempting, coordinate,
lodge,confess, grant, proceed ,display, consequently
2 Whenever my boss makes a decision that I don't agree with, I tell him what I really think, though it's [ ] to make him happy by telling him his ideas are always right
【填空题】
commence,deserve,tempting, coordinate,
lodge,confess, grant, proceed ,display, consequently
3 As can be probably perceived, a manned tip to Mars may soon[ ] since scientists have achieved the manned moon mlssion
【填空题】
commence,deserve,tempting, coordinate,
lodge,confess, grant, proceed ,display, consequently
4 A number of countries are [ ]their efforts to send out food to the area worst affected by the flood.
