相关试题
【单选题】
晶闸管触发电路发出触发脉冲的时刻是由___来定位的，由偏置电压来调整初始相位，由控制电压来实现移相。
A. 脉冲电压
B. 触发电压
C. 异步电压
D. 同步电压
【单选题】
晶闸管触发电路发出触发脉冲的时刻是由同步电压来定位的，由___来调整初始相位，由控制电压来实现移相。
A. 脉冲电压
B. 触发电压
C. 偏置电压
D. 异步电压
【单选题】
KCO4集成触发电路由锯齿波形成、___、脉冲形成及整形放大输出等环节组成。
A. 三角波控制
B. 移相控制
C. 方波控制
D. 偏置角形成
【单选题】
KCO4集成触发电路中11脚和12脚上所接的R8、C2决定输出脉冲的___。
【单选题】
KCO4集成触发电路在3脚与4脚之间的外接电容器Cl上形成___。
A. 正弦波
B. 三角波
C. 锯齿波
D. 方波
【单选题】
KCO4集成触发电路中，锯齿波同步电压与直流偏置电压和直流控制电压进行___。
A. 串联叠加
B. 并联叠加
C. 微分叠加
D. 积分叠加
【单选题】
KCO4集成触发电路一个周期内可以从1脚和15脚分别输出相位差___的两个窄脉冲。
A. 60°
B. 90°
C. 120°
D. 180°
【单选题】
用PLC控制可以节省大量继电-接触器控制电路中的___。
A. 熔断器
B. 交流接触器
C. 开关
D. 中间继电器和时间继电器
【单选题】
在FX系列PLC控制中可以用___替代中间继电器。
【单选题】
PLC编程语言用得最普遍的是___。
A. 指令表
B. 梯形图
C. 顺序功能图
D. 结构化文本
【单选题】
在FX2NPLC中PLS是___指令。
A. 计数器
B. 定时器
C. 上升沿脉冲
D. 下降沿脉冲
【单选题】
在FX2NPLC中PLF是___指令。
A. 下降沿脉冲
B. 上升沿脉冲
C. 暂停
D. 移位
【单选题】
FX2系列可编程序控制器的上升沿脉冲指令，可以___。
A. 配合高速计数器
B. 隔离电源干扰
C. 防止输入信号消失
D. 防止输入信号抖动
【单选题】
FX2N系列可编程序控制器的上升沿脉冲指令，可以___。
A. 隔离输出
B. 防止输入信号抖动
C. 延时
D. 快速读人
【单选题】
FX2NPLC中使用SET指令时必须___。
A. 配合使用停止按钮
B. 配合使用置位指令
C. 串联停止按钮
D. 配合使用RST指令
【单选题】
在FX系列PLC控制中可以用___替代计数器。
【单选题】
FX.m系列可编程序控制器在使用计数器指令时需要配合使用___指令。
A. STL
B. RST
C. OUT
D. PIS
【单选题】
在FXN PLC中要配合使用PIS实现___功能。
【单选题】
在FXoNPLC中，T100的定时精度为___。
A. 1ms
B. 10ms
C. 100ms
D. 10s
【单选题】
在FX2N PLC中，T200的定时精度为___。
A. 1ms
B. 10ms
C. 100ms
D. 1s
【单选题】
在FX2NPLC中，TO的定时精度为___。
A. 10ms
B. 100ms
C. 1s
D. 1ms
【单选题】
在FX，NPLC中，___是积算定时器。
A. TO
B. T100
C. T245
D. T255
【单选题】
在以下FX2NPLC程序中，X0闭合后经过___s时间延时，YO得电。
A. 3000
B. 300
C. 30000
D. 3100
【单选题】
在使用FX2x可编程序控制器控制交通灯时，将相对方向的同色灯并联起来，是为了___。
A. 减少输出电流
B. 节省PLC输出口
C. 提高输出电压
D. 提高工作可靠性
【单选题】
在使用FX小可编程序控制器控制交通灯时，将相对方向的同色灯并联起来，是为了___。
A. 简化电路
B. 节约电线
C. 节省PLC输出口
D. 减少工作量
【单选题】
在使用FX2v可编程序控制器控制电动机星三角启动时，至少需要使用___个交流接触器。
【单选题】
___不是PLC控制系统设计的原则。
A. 只需保证控制系统的生产要求即可，其他无须考虑
B. 最大限度地满足生产机械或生产流程对电气控制的要求
C. 在满足控制系统要求的前提下，力求使系统简单、经济、操作和维护方便
D. PLC的LVO点数要留有一定余量
【单选题】
以下不是PLC控制系统设计原则的是___。
A. 最大限度地满足生产机械或生产流程对电气控制的要求
B. 导线越细成本越低
C. 在满足控制系统要求的前提下，力求使系统简单、经济、操作和维护方便
D. 以上都是
【单选题】
下列选项不是PLC控制系统设计原则的是___。
A. 保证控制系统的安全可靠
B. 最大限度地满足生产机械或生产流程对电气控制的要求
C. 在选择PLC时要求输入输出点数全部使用
D. 在满足控制系统要求的前提下，力求使系统简单、经济、操作和维护方便
【单选题】
以下不是PLC控制系统设计原则的是___。
A. 保证控制系统的安全可靠
B. 最大限度地满足生产机械对电气的要求
C. 在满足控制要求的同时，力求使系统简单、经济、操作和维护方便
D. 选择价格贵的PLC来提高系统可靠
【单选题】
PLC控制系统的主要设计内容不包括___。
A. 选择用户输入设备、输出设备以及由输出设备驱动的控制对象
B. PLC的保养和维护
C. 分配VO点，绘制电气连接图，考虑必要的安全保护措施
D. 必要时设计控制柜
【单选题】
PLC控制系统的主要设计内容描述不正确的是___。
A. 选择用户输入设备、输出设备以及由输出设备驱动的控制对象
B. 分配VO点，绘制电气连接图，考虑必要的安全保护措施
C. 编制控制程序
D. 下载控制程序
【单选题】
PLC控制系统设计的步骤是___。1正确选择PLC来保证控制系统的技术和经济性能指标2深入了解控制对象及控制要求3系统交付前，要根据调试的最终结果整理出完整的技术文件4PLC进行模拟调试和现场调试
A. 2-1-4-3
B. 1-2-4-3
C. 4-2-1-3
D. 1-3-2-4
【单选题】
PLC控制系统设计的步骤是___。1确定硬件配置，画出硬件接线图2PLC进行模拟调试和现场调试3系统交付前，要根据调试的最终结果整理出完整的技术文件4深入了解控制对象及控制要求
A. 1324
B. 1243
C. 2143
D. 4123
【单选题】
以下PLC控制系统设计的步骤描述错误的是___。
A. 正确选择PLC对于保证控制系统的技术和经济性能指标起着重要的作用
B. 深入了解控制对象及控制要求，是PLC控制系统设计的基础
C. 系统交付前，要根据调试的最终结果整理出完整的技术文件
D. PLC进行程序调试时直接进行现场调试即可
【单选题】
以下PLC控制系统设计的步骤描述不正确的是___。
A. PLC的LVO点数要大于实际使用数的两倍
B. PLC程序调试时，进行模拟调试和现场调试
C. 系统交付前，要根据调试的最终结果整理出完整的技术文件
D. 确定硬件配置，画出硬件接线图
【单选题】
以下PLC编程软件安装方法不对的是___。
A. 安装前，请确定下载文件的大小及文件名称
B. 在安装的时候，最好把其他应用程序关掉，包括杀毒软件
C. 安装选项中，选项无需都打勾
D. 解压后，直接点击安装
【单选题】
PLC编程软件安装方法不正确的是___
A. 安装选项中，所有选项要都打勾
B. 先安装通用环境，解压后，进入相应文件夹，点击安装
C. 在安装的时候，最好把其他应用程序关掉，包括杀毒软件
D. 安装前，请确定下载文件的大小及文件名称
【单选题】
PLC编程软件安装方法不正确的是___。
A. 安装前，请确定下载文件的大小及文件名称
B. 安装过程中，每一步都要杀毒
C. 在安装的时候，最好把其他应用程序关掉，包括杀毒软件
D. 先安装通用环境，解压后，进入相应文件夹，点击安装
【单选题】
以下PLC编程软件安装方法不正确的是___。
A. 安装前，请确定下载文件的大小及文件名称
B. 在安装的时候，最好把其他应用程序关掉，包括杀毒软件
C. 安装前，要保证VO接口电路连线正确
D. 先安装通用环境，解压后，进入相应文件夹，点击安装
推荐试题
【单选题】
How did the speaker feel about his childhood? ___
A. Alone.
B. Happy.
C. Sad.
D. Interesting.
【单选题】
Which is NOT mentioned when the speaker curled up in a chair? ___
A. Reading fairytales and myths.
B. Daydreaming.
C. Writing poems.
D. Listening to music.
【单选题】
What kind of person was the speaker’s grandma? ___
A. Often critical, judgmental.
B. Very strict.
C. Easygoing.
D. Successful.
【单选题】
When was the speaker’s first conscious memory of feeling different? ___
A. Fourth grade.
B. Fifth grade.
C. First grade.
D. Second grade.
【单选题】
Which is NOT included in the speaker’s inner world? ___
A. Reading books.
B. Writing.
C. Watching TV.
D. Daydreaming.
【单选题】
What does integrity mean? ___
A. You do what you do because it's fashionable.
B. You do what you do because it's politically correct.
C. You do what you do because it's right.
D. You do what you do because somebody asked you to.
【单选题】
Is there cheating in World Cup? ___
A. It's none.
B. It's rare.
C. It's some.
D. It's popular.
【单选题】
Which one of the following situations is NOT mentioned for making us upset? ___
A. Some reward we thought we deserved has been denied us.
B. Some man we helped has proved ungrateful.
C. Some man we believed to be a friend has betrayed us.
D. Some woman we believed to be a friend has spoken ill of us.
【单选题】
In which year the Tour of France was hit by a drug-taking scandal? ___
A. In 1996.
B. In 1997.
C. In 1998.
D. In 1999.
【单选题】
Cheap fake products are everywhere except ___
A. clothes.
B. cut-price DVDs.
C. cut-price CDs.
D. cosmetics.
【单选题】
What should we do after exercise? ___
A. Stretch the muscles.
B. Have a sleep.
C. Maintain high body temperature.
D. Take a shower.
【单选题】
What shouldn’t we wear when we exercise? ___
A. Properly fitted sportswear.
B. Well-fitted sneakers.
C. Tight pants.
D. Sports bra for women.
【单选题】
Which of the following is NOT good for health? ___
A. Training with a friend.
B. Slack off a fitness regimen.
C. Keep our body hydrated.
D. Take small sips every few minutes.
【单选题】
What does the speaker do? ___
A. Public relations consultant.
B. Home cook.
C. Website administrator.
D. Writer.
【单选题】
Which is NOT included in the speaker’s favorite breakfasts? ___
A. Egg.
B. Prosciutto.
C. Papaya.
D. Cabbage.
【单选题】
When do the students start learning Chinese? ___
A. Since kindergarten
B. Since elementary school
C. Since middle school
D. Since high school
【单选题】
When can the students continue studying Chinese? ___
A. In elementary school and middle school.
B. In middle school and high school.
C. In high school and university
D. After the university.
【单选题】
How many American students are currently learning Chinese? ___
A. About 22,000
B. About 24,000
C. About 44,000
D. About 2,400
【单选题】
How much did the Defense Department give Oregon schools? ___
A. $70,000
B. $1.3 million
C. $700,000
D. $1.3 billion
【单选题】
What’s Isabel Weiss’s purpose of learning Chinese? ___
A. For fun
B. For more opportunities for jobs
C. For more opportunities of making money
D. For more opportunities for promotions
【单选题】
What ability do the standardized tests reward to? ___
A. Think.
B. Create.
C. Quickly answer superficial questions.
D. Above all.
【单选题】
In what ways the IQ scores can be changed? ___
A. Training.
B. Nutrition.
C. More friendly people administered the test.
D. Above all
【单选题】
What do schools focus on? ___
A. Concepts.
B. Science.
C. Social Studies.
D. Foreign languages.
【单选题】
Why tests and standards are a necessary fact of life? ___
A. They protect us from hazardous products.
B. They protect us from inept drivers.
C. They protect us from shoddy professionals.
D. Above all.
【单选题】
How many percent did the scores on statewide tests rise? ___
A. 4%.
B. 14%.
C. 40%.
D. None.
【单选题】
What was the woman’s reaction when she was nominated? ___
A. She was surprised at the nomination.
B. She was calm at the nomination.
C. She was indifferent to the nomination.
D. She was scared of the nomination.
【单选题】
According to the woman, who paid for her trip to San Francisco? ___
A. Her trip to San Francisco was sponsored by the Academy.
B. Her trip to San Francisco was paid for by her company.
C. Her trip to San Francisco was paid for by her family.
D. Her trip to San Francisco was paid for by herself.
【单选题】
What is the name of George Miller’s new movie? ___
A. Happy Feeling.
B. Happy Dancing.
C. Happy Foot.
D. Happy Feet.
【单选题】
Which name is not mentioned in the film? ___
A. Nicole Kidman.
B. Hugh Jackman.
C. George Clooney.
D. Robin Williams.
【单选题】
Which of the following statement is not true about “Life in the Freezer”? ___
A. It was a documentary film.
B. It was made by National Geographic and the BBC.
C. It was a story of the amazing life of Emperor penguins.
D. The
E. mperor penguin sang to each other to find a mate and made friends.
【单选题】
What should you do during a high-pressure periods? ___
A. Lock yourself in a room with your work.
B. Leave your work and go on a vocation.
C. Tell your boss you can’t finish your work.
D. Get together with people who will revitalize and inspire you.
【单选题】
Which of the following is the correct description of TempWorld? ___
A. The era of guaranteed jobs is history.
B. We are all temporary workers.
C. You have to equip yourself with the skills.
D. All of the above.
【单选题】
What should a career activist do? ___
A. Being a career activist means concentrating on daily business.
B. Being a career activist means you can do a business as long as it meets your short-term needs.
C. A career activist should take the long view of his career.
D. A career activist should plan everything in advance.
【单选题】
What should you do in the TempWorld? ___
A. In TempWorld you must withstand disappointment, juggle stressful situations, and handle pressure.
B. You must learn from your setbacks and use them to your advantage in the future.
C. Things always go well for successful people because they are honest.
D. Both A and B.
【单选题】
Which of the following statements is Not True? ___
A. Your boss may be willing to change his behavior than your think.
B. Some managers don’t care how much their words or actions upset staffers.
C. You should tell your managers how their outbursts make you feel.
D. If the boss values your work, he may stop his abusiveness.
【单选题】
Which of the following public places is NOT mentioned that have banned mobiles? ___
A. restaurants
B. gas stations
C. theatres
D. museums
【单选题】
What happened when the cellphone of the speaker’s friend rang? ___
A. His friend answered the phone and the speaker became invisible to his friend.
B. They answered the phone together.
C. The speaker threw away his friend’s cellphone.
D. His friend hung up the phone and kept talking to the speaker. (C)
【单选题】
What happened to the man? ___
A. He had a car accident.
B. He had his arms broken.
C. He lost his mobile phone.
D. He was not able to use his mobile because he was in a remote area.
【单选题】
Which of the following is NOT true? ___
A. Today there are about 400 million cellphone owners.
B. Today there are about 300 million Personal Computer subscribers.
C. Cellphones will be more often used.
D. Cellphones will completely replace Personal Computers.
【单选题】
Which of the following is true? ___
A. Ellen Johnson-Sirleaf stayed in her country during the nation’s civil war.
B. She is still working for the United Nations.
C. She is the first woman ever elected president of an Asian country.
D. She is a Liberia.
