20春学期《电机拖动》在线平时作业2

adminhan

&nbsp; <p style="LINE-HEIGHT: 150%" class="MsoNormal"><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-size: 10.5pt">连续工作制电机工作时温升达到稳定温升（</span><span style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt" lang="EN-US"><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp; </span></span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-size: 10.5pt">）</span><span style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt" 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-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">三相异步电动机旋转磁场转速与电源频率成正比，与电机极对数成反比。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"> </span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">　）</span>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-SIZE: 10.5pt">电机处于电动状态时，电磁转矩与转向相同。（　）<span lang="EN-US"><o:p></o:p></span></span></p>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">电刷轴线两边导体中电流方向相反。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"> <span style="mso-spacerun: yes">&nbsp;</span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">　）</span>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-SIZE: 10.5pt">交流绕组短距系数是不大于<span lang="EN-US">1</span>的数值。（ 　）<span lang="EN-US"><o:p></o:p></span></span></p>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-SIZE: 10.5pt">异步电动机处于正向回馈状态时，转差率<span lang="EN-US">s&lt;0</span>。（ 　）<span lang="EN-US"><o:p></o:p></span></span></p>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">机械特性曲线硬度好，表示电磁转矩有较大变化时，电机转速变化不大。（　）</span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">电机处于电动状态时，电磁转矩与转向相同。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"> <span style="mso-spacerun: yes">&nbsp;</span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">　）</span>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-SIZE: 10.5pt">定子旋转磁场与转子同步。（　）<span lang="EN-US"><o:p></o:p></span></span></p>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-SIZE: 10.5pt">一相交流绕组通入正弦交流电产生旋转磁场。（　）<span lang="EN-US"><o:p></o:p></span></span></p>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">在变压器中由交变磁通产生的感应电动势，其正方向与产生该磁通的电流方向相反。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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; </span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">）</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"><br style="mso-special-character: line-break" /><br style="mso-special-character: line-break" /></span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">同时改变直流电动机电枢两端和励磁两端电压极性，可以改变电机转向。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"> <span style="mso-spacerun: yes">&nbsp;</span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">　）</span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">直流电机的电枢绕组是闭合的。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"> <span style="mso-spacerun: yes">&nbsp;</span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">　）</span>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-SIZE: 10.5pt">三相异步电动机以最大转矩起动，临界转差率为<span lang="EN-US">1</span>。（ 　）<span lang="EN-US"><o:p></o:p></span></span></p>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">变压器的效率是输出有功功率与输入有功功率之比。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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; </span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">）</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"><br style="mso-special-character: line-break" /><br style="mso-special-character: line-break" /></span>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-SIZE: 10.5pt">电动机能耗制动比反接制动更消耗电能。（　）<span style="COLOR: red" lang="EN-US"><o:p></o:p></span></span></p>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">绕线式异步电动机转子回路串电阻越大，起动转矩越大，最大转矩也越大。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"> </span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　）</span>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-SIZE: 10.5pt">使用变压器标幺值计算电路参数，要将二次侧参数折算到一次侧。（　）<span lang="EN-US"><o:p></o:p></span></span></p>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">气隙增大，电机磁路的磁阻也将增大。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"> <span style="mso-spacerun: yes">&nbsp;</span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">　）</span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">三相异步电动机正常运行时，负载转矩增加，转差率增大。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"> </span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　）</span>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">一台三相异步电动机，电源频率为</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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" lang="EN-US">50Hz</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">极对数是</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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" lang="EN-US">2</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">这台电动机的旋转磁场转速为</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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" lang="EN-US">3000</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">转</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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" lang="EN-US">/</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">分。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"> </span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">　）</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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" lang="EN-US"><br style="mso-special-character: line-break" /><br style="mso-special-character: line-break" /></span>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-SIZE: 10.5pt">三相异步电动机额定转速<span lang="EN-US">1470r/min</span>，则同步转速也是<span lang="EN-US">1470r/min</span>。（ 　）<span lang="EN-US"><o:p></o:p></span></span></p>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-SIZE: 10.5pt">绕线异步电动机，如果负载转矩不变则转子回路串不同电阻时临界转矩不变。（　）<span lang="EN-US"><o:p></o:p></span></span></p>
A:错误
B:正确

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">发电机的电磁转矩和空载转矩是阻碍电机旋转的制动转矩。（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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"> <span style="mso-spacerun: yes">&nbsp;</span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; 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">　）</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; 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" lang="EN-US"><br style="mso-special-character: line-break" /><br style="mso-special-character: line-break" /></span>
A:错误
B:正确

&nbsp; <p style="LINE-HEIGHT: 150%" class="MsoNormal"><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-size: 10.5pt">电动机运行时间与工作周期之比成为负载持续率（</span><span style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt" lang="EN-US"><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-size: 10.5pt">）</span><span style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt" lang="EN-US"><o:p></o:p></span></p>
A:错误
B:正确