20春学期《测试技术基础》在线平时作业3

adminhan

<p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-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">频域<span style="COLOR: black; mso-bidi-font-weight: bold">信号与</span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-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">相应的<span style="COLOR: black; mso-bidi-font-weight: bold">时域</span>信号</span></p><p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-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="599" height="103" alt="" src="http://file.open.com.cn/ItemDB/65628/0549f5f9-723c-4e46-b0dd-01231894a0c9/2014610215237898.jpg" /></span></p>
A:A
B:B
C:C
D:D

<p><font size="4">两个信号叠加:</font></p><p><img width="595" height="159" alt="" src="http://file.open.com.cn/ItemDB/65628/6ac95ca9-0f80-46d5-8105-b2e8015e180d/2014610181138149.jpg" /></p>
A:A
B:B
C:C
D:D

<br>按照奈奎斯特采样定理，采样频率至少为（）<br>（A）有用的最高频率的一半<br>(B)有用的最高频率的两倍<br>(C)与有用的最高频率相同<br>(D)有用的最高频率的3倍<br><br>
A:A
B:B
C:C
D:D

选择题:<br>由两个时间具有少量频率差的波形引起的拍频等于（）<br>（A）两个频率的平均<br>（B）两个频率的和<br>（c）两个频率的差<br>（D）两个频率之比<br><br>
A:A
B:B
C:C
D:D

<span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-fareast-language: ZH-CN; 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-bidi-language: AR-SA">记录磁带慢录快放，放演信号的频谱带宽<strong style="mso-bidi-font-weight: normal"><u><span style="COLOR: red">（</span></u></strong></span><strong style="mso-bidi-font-weight: normal"><u><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: &quot;Times New Roman&quot;; COLOR: red; mso-fareast-language: ZH-CN; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体"><span style="mso-spacerun: yes">&nbsp;&nbsp;</span> <span style="mso-spacerun: yes">&nbsp;&nbsp; </span></span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; COLOR: red; mso-fareast-language: ZH-CN; 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-bidi-language: AR-SA">）</span></u></strong>
A:变窄，幅值压低
B:扩展，幅值压低
C:变窄，幅值增高
D:扩展，幅值增高

<p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">将若矩形窗函数</span></p><p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><img width="499" height="99" alt="" src="http://file.open.com.cn/ItemDB/65628/0556414e-8047-486b-a9ff-d6e0c7a6fcb1/2014615133113244.jpg" /></span></p>
A:A
B:B
C:C
D:D

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-font-kerning: 1.0pt; mso-hansi-font-family: 'Times New Roman'">当某些晶体沿一定方向受外力作用而变形时，其相应的两个相对表面产生极性相反的电荷，去掉外力时电荷消失，这种现象称为（</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 12pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体" lang="EN-US"><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;</span></span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 12pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体" lang="EN-US"><span style="mso-spacerun: yes">&nbsp;&nbsp;</span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-font-kerning: 1.0pt; mso-hansi-font-family: 'Times New Roman'">）。</span>
A:压阻效应
B:压敏效应
C:逆压电效应
D:正压电效应

<p><img height="117" alt="" width="392" src="http://file.open.com.cn/ItemDB/65628/dd183efd-32af-4888-ae49-9a0f4d784732/20102114641404.jpg" /></p><p>&nbsp;</p><p>xua选择题</p>
A:A
B:B
C:C
D:D

<p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-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"><strong>两个信号叠加:</strong></span></p><p><span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-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"><strong><img width="597" height="143" alt="" src="http://file.open.com.cn/ItemDB/65628/890c97bd-5f0a-4320-809c-f8ca9e0bde7d/2014610214012968.jpg" /></strong></span></p>
A:A
B:B
C:C
D:D

<p>不失真的幅频相频特性</p><p><img height="127" width="443" alt="" src="http://file.open.com.cn/ItemDB/65628/37d66957-5efd-4a2d-9ae3-d623287dd384/201021145346144.jpg" /></p>
A:A
B:B
C:C
D:D

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">附加传感器质量将使被测振动系统的固有频率<strong style="mso-bidi-font-weight: normal"><span style="COLOR: black">降低</span><u><span style="COLOR: red">。</span></u></strong></span><strong><u><span style="FONT-FAMILY: 宋体; COLOR: red; FONT-SIZE: 14pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">（&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ）</span></u></strong>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 12pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-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; mso-bidi-font-weight: bold">若信号的独立变量取值离散，则是<strong>离散信号</strong>。</span>
A:错误
B:正确

<span style="FONT-SIZE: 12pt; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; 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">传感器的功能是将被测信息转换成某种电信号的器件。它包括敏感器和转换器两部分。</span>
A:错误
B:正确

<span style="FONT-SIZE: 14pt; COLOR: red; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'"><strong><u>判断题</u></strong></span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">实心圆柱弹性元件高度</span><em><span lang="EN-US" style="FONT-SIZE: 12pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">H</span></em><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">变小时，弹性元件固有频率降低。</span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; 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; mso-bidi-font-weight: bold">引用误差是仪表的最大示值误差与仪表的<strong><span style="COLOR: black">满量程</span></strong></span><u><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 12pt; 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"><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span></span></u><strong><span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; 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">之比。</span><u><span style="FONT-FAMILY: 宋体; COLOR: red; FONT-SIZE: 14pt; 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">（</span><span style="FONT-FAMILY: 宋体; COLOR: red; FONT-SIZE: 12pt; 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">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="FONT-FAMILY: 宋体; COLOR: red; FONT-SIZE: 14pt; 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">）</span></u></strong>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-weight: bold; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">椭圆齿轮流量计是借助于固定的容积来计量流量的，与流体的流动状态及粘度有关。<strong><u><span style="COLOR: red">（&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ）</span></u></strong></span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">稳态正弦激振是最普遍的激振方法，它是借助激振设备对被测对象施加一个频率可控的瞬态激振力。</span><strong><u><span style="FONT-FAMILY: 宋体; COLOR: red; FONT-SIZE: 14pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">（&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ）</span></u></strong>
A:错误
B:正确

<p class="MsoNormal" style="MARGIN: 0cm 0cm 6pt 34.45pt; TEXT-INDENT: -34.45pt; mso-char-indent-count: -2.45"><strong><u><span style="FONT-SIZE: 14pt; COLOR: red; FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">判断题</span></u></strong><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">轮辐式弹性元件形似带有辐条的车轮。应变片沿轮辐轴线成</span><span lang="EN-US" style="FONT-SIZE: 12pt"><font face="Times New Roman">45^o </font></span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">角的方向贴于梁的两个侧面。</span></p>
A:错误
B:正确

<p style="TEXT-INDENT: -23.5pt; MARGIN: 0cm 0cm 0pt 23.5pt; mso-char-indent-count: -1.96" class="MsoNormal"><span style="FONT-FAMILY: 宋体; FONT-SIZE: 12pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">测量扭矩使用的水银集流装置和电刷&mdash;滑环集流装置相比，<strong style="mso-bidi-font-weight: normal"><span style="COLOR: black">水银集流装置</span></strong>的接触电阻大，测量精度高。</span><strong><u><span style="FONT-FAMILY: 宋体; COLOR: red; FONT-SIZE: 14pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">（&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ）</span></u></strong><span style="FONT-SIZE: 12pt" lang="EN-US"><o:p></o:p></span></p>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-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; mso-bidi-font-size: 12.0pt">方波是由奇次谐波的时间波形合成的。</span>
A:错误
B:正确