【单选题】
变压器负载运行时,随着负载电流的增大,其铁心损耗<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205100008_669.png"/>和铜损耗<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205100015_370.png"/>会()
①
<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205095339_393.png"/>增大,<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205095346_882.png"/>不变
②
<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205095355_176.png"/>不变,<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205095359_427.png"/>增大
【单选题】
单相变压器磁路饱和时,主磁通<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205101139_207.png"/>和励磁电流<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205100752_202.png"/>的波形()
【单选题】
甲乙两个车间工人日加工零件数的均值和标准差如下:甲车间:<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191204/20191204133016_901.png"/>=70件,<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191204/20191204133853_863.png"/>=5.6件,乙车间:<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191204/20191204132636_598.png"/>=90件,<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191129/20191129164519_624.png"/>=6.3件,哪个车间日加工零件的离散程度较大()
【单选题】
额定电压为220/110V的单相变压器,低压边漏电抗为0.075<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205095750_736.png"/>,折合到一次侧为:
①
0.075<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205100447_597.png"/>
②
0.15<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205100458_35.png"/>
③
0.3<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205095823_483.png"/>
【单选题】
关于三相异步电动机转子边产生的磁动势<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205101252_49.png"/>的旋转速度说法正确的是()
①
相对定子边磁动势<imgalt=""src="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205101305_33.png"/>静止
【单选题】
同步发电机直轴电抗<imgsrc="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191121/20191121093404_378.png"alt=""/>三者之间的大小关系为()。
①
<imgsrc="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191121/20191121095321_129.png"alt=""/>
②
<imgsrc="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191121/20191121095408_167.png"alt=""/>
③
<imgsrc="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191121/20191121095350_584.png"alt=""/>
【单选题】
根据等效关系的传递性,若有状态<imgwidth="24"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj056978.png">和<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057002.png">等效,又有状态<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057032.png">和<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057056.png">等效,则状态<imgwidth="24"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057085.png">和<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057109.png">也等效。正确的写法是:______。
①
(<imgwidth="24"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057153.png">,<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057177.png">),(<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057203.png">,<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057227.png">)-à(<imgwidth="50"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057254.png">)
②
(<imgwidth="50"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057281.png">),(<imgwidth="54"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057307.png">)-à(<imgwidth="50"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057334.png">)
③
(<imgwidth="24"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057361.png">,<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057385.png">),(<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057411.png">,<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057435.png">)-à(<imgwidth="24"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057462.png">,<imgwidth="25"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057486.png">)
④
(<imgwidth="50"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057513.png">),(<imgwidth="54"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057539.png">)-à(<imgwidth="54"height="34"src="http://wljy.whut.edu.cn:80/uploadfiles/word/szlj05.files/szlj057566.png">)
【单选题】
设<imgwidth="69"height="22"v:shapes="_x0000_i1152"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image208.png">是来自正态总体<imgwidth="58"height="22"v:shapes="_x0000_i1153"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image210.png">的样本,已知统计量<imgwidth="118"height="22"v:shapes="_x0000_i1154"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image212.png">是方差<imgwidth="18"height="18"v:shapes="_x0000_i1155"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image214.png">的无偏估计量,则常数<imgwidth="12"height="18"v:shapes="_x0000_i1156"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image216.png">等于()
①
<imgwidth="12"height="37"v:shapes="_x0000_i1157"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image218.png">
②
<imgwidth="12"height="37"v:shapes="_x0000_i1158"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image220.png">
【单选题】
设总体<imgwidth="14"height="14"v:shapes="_x0000_i1069"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image002.png">服从两点分布:<imgwidth="259"height="20"v:shapes="_x0000_i1070"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image080.png"><imgwidth="75"height="26"v:shapes="_x0000_i1071"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image081.png">为其样本,则样本均值<imgwidth="12"height="18"v:shapes="_x0000_i1072"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image083.png">的期望<imgwidth="49"height="20"v:shapes="_x0000_i1073"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image085.png">()
①
<imgwidth="12"height="18"v:shapes="_x0000_i1074"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image087.png">
②
<imgwidth="18"height="22"v:shapes="_x0000_i1075"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image089.png">
③
<imgwidth="32"height="22"v:shapes="_x0000_i1076"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image091.png">
④
<imgwidth="20"height="22"v:shapes="_x0000_i1077"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image093.png">
【单选题】
设总体<imgwidth="84"height="22"v:shapes="_x0000_i1356"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image412.png">,<imgwidth="20"height="20"v:shapes="_x0000_i1357"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image461.png">未知,<imgwidth="75"height="26"v:shapes="_x0000_i1358"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image476.png">是来自<imgwidth="12"height="14"v:shapes="_x0000_i1359"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image426.png">的样本,<imgwidth="12"height="20"v:shapes="_x0000_i1360"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image478.png">为样本均值,<imgwidth="12"height="14"v:shapes="_x0000_i1361"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image480.png">为样本标准差。是检验问题为<imgwidth="164"height="22"v:shapes="_x0000_i1362"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image482.png">则检验的统计量为()
①
<imgwidth="135"height="35"v:shapes="_x0000_i1363"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image484.png">
②
<imgwidth="135"height="35"v:shapes="_x0000_i1364"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image486.png">
③
<imgwidth="135"height="37"v:shapes="_x0000_i1365"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image488.png">
④
<imgwidth="115"height="37"v:shapes="_x0000_i1366"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image490.png">
【单选题】
设<imgwidth="95"height="22"v:shapes="_x0000_i1198"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image265.png">与<imgwidth="78"height="22"v:shapes="_x0000_i1199"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image267.png">都是来自于总体<imgwidth="14"height="14"v:shapes="_x0000_i1200"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image154.png">的两独立样本,<imgwidth="14"height="20"v:shapes="_x0000_i1201"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image268.png">,<imgwidth="12"height="20"v:shapes="_x0000_i1202"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image247.png">与<imgwidth="46"height="22"v:shapes="_x0000_i1203"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image270.png">分别是两样本的均值和方差,<imgwidth="144"height="22"v:shapes="_x0000_i1204"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image272.png">,则有()
①
对于任意的常数<imgwidth="179"height="22"v:shapes="_x0000_i1205"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image274.png">是<imgwidth="12"height="18"v:shapes="_x0000_i1206"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image276.png">的无偏估计,且<imgwidth="73"height="42"v:shapes="_x0000_i1207"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image278.png">,<imgwidth="73"height="42"v:shapes="_x0000_i1208"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image280.png">,<imgwidth="32"height="20"v:shapes="_x0000_i1209"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image282.png">达到最小
②
对于任意的常数<imgwidth="179"height="22"v:shapes="_x0000_i1210"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image274.png">是<imgwidth="12"height="18"v:shapes="_x0000_i1211"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image276.png">的无偏估计,且<imgwidth="73"height="42"v:shapes="_x0000_i1212"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image278.png">,<imgwidth="73"height="42"v:shapes="_x0000_i1213"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image280.png">,<imgwidth="32"height="20"v:shapes="_x0000_i1214"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image282.png">达到最小
③
对于任意常数<imgwidth="95"height="29"v:shapes="_x0000_i1215"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image284.png">,<imgwidth="202"height="26"v:shapes="_x0000_i1216"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image286.png">都是<imgwidth="12"height="18"v:shapes="_x0000_i1217"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image276.png">的无偏估计,并且当<imgwidth="46"height="40"v:shapes="_x0000_i1218"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image288.png">时,<imgwidth="35"height="20"v:shapes="_x0000_i1219"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image290.png">达到最小
④
对于任意常数<imgwidth="84"height="26"v:shapes="_x0000_i1220"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image291.png">,<imgwidth="207"height="26"v:shapes="_x0000_i1221"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image292.png">都是<imgwidth="12"height="18"v:shapes="_x0000_i1222"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image276.png">的无偏估计