20春学期《机械设备电气控制（含PLC）》在线平时作业2

adminhan

<div>从组成结构形式上，PLC可以分为（&nbsp; ）</div>
A:整体式、模块式
B:独立式、协同式
C:整体式、独立式
D:模块式、独立式

&nbsp; <p class="MsoNormal"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">保持电源电压不变，电枢回路不串联电阻，当磁通减小时，理想空载转速、机械特性的斜率分别（</span> <span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">）</span></p>
A:<font face="宋体">减小、减小</font>
B:<font face="宋体">减小、增大</font>
C:<font face="宋体">增大、减小</font>
D:<font size="3" face="宋体">增大、增大</font>

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">数控机床电气控制系统由（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体"> </span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">）、进给伺服系统、主轴伺服系统、机床强电控制系统等组成。</span>
A:<div>液压系统</div>
B:弱电控制系统
C:硬件系统
D:数控装置

<div>下列哪种不属于三相异步电机常用的调速途径（ ）</div>
A:改变定子绕组极对数
B:改变转差率
C:改变电枢电流
D:改变电源频率

<div>图示梯形图方块为（&nbsp; ）</div><div><img width="217" height="196" alt="" src="http://file.open.com.cn/ItemDB/77902/ce667db0-d79c-4de2-b20f-96d813ce85e2/2010102915817560.JPG" /></div>
A:定时器指令
B:计数器指令
C:置位指令
D:输出指令

<div>直流电动机的定子主要由机座、（）、换向磁极、电刷装置、前后端盖等构成。</div>
A:线圈绕组
B:励磁绕组
C:磁通
D:主磁极

<p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">下列图形是（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">&nbsp; </span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">）的图形符号</span></p><p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><img width="211" height="96" alt="" src="http://file.open.com.cn/ItemDB/77902/f183f63d-e651-41a9-978e-8f2d418e37c4/20101029111616709.JPG" /></span></p>
A:<div>熔断器</div>
B:热继电器
C:电流继电器
D:电压继电器

<div>电动机的机械特性指电源电压为常数、励磁电流为常数、电枢回路电阻为常数时，电动机的电磁转矩与（ ）之间的关系。</div>
A:转速
B:电压
C:磁通
D:转速

<div>图示梯形图方块为（&nbsp;&nbsp; ）</div><div>&nbsp;<img width="272" height="246" alt="" src="http://file.open.com.cn/ItemDB/77902/26325248-2e8c-4358-93fe-05e434e6f606/201010291594063.JPG" /></div>
A:定时器指令
B:计数器指令
C:置位指令
D:输出指令

<p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">下列图形是（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">&nbsp; </span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">）的图形符号</span></p><p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><img style="WIDTH: 51px; HEIGHT: 103px" width="142" height="257" alt="" src="http://file.open.com.cn/ItemDB/77902/6fd5b692-681f-4ed1-af34-bd6edfa83754/2010102911139875.JPG" /></span></p>
A:&nbsp;<p class="MsoNormal"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">熔断器</span></span></p>
B:<font face="宋体">热继电器</font>
C:<font face="宋体">电流继电器</font>
D:<font face="宋体">电压继电器</font>

<span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">PLC</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">应用最基本、最广泛的领域是位置控制方面。</span>
A:错误
B:正确

&nbsp;自动控制系统的动态性能要求是稳定性。
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">三相笼型异步电机有全压起动和降压起动两种方式。</span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">步进电电将电脉冲信号转换为角位移，精度很高，误差不会累积。</span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">熔断器可以用作过载保护器。</span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">直线控制系统的刀具运动轨迹一般是平行于各坐标轴的直线，因此刀具运动轨迹不能与坐标轴成一定夹角。</span>
A:错误
B:正确

<span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">PLC</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">不仅应用于逻辑控制场合，还适用于模拟量和数字量的控制。</span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">桥式触点有点接触和面接触两种，前者适用于小电流电路，后者适用于大电流电路。</span>
A:错误
B:正确

<p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">大容量的直流电动机可直接起动。</span></p>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">在直流电力拖动自动控制系统中，降低电枢电压调速得到广泛应用。</span>
A:错误
B:正确