【单选题】【消耗次数：1】
在电力系统潮流计算中，PV节点的待求量是()
①
Q、<imgsrc="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205080031_752.png"alt=""/>
②
P、Q
③
V、<imgsrc="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205080043_336.png"alt=""/>
④
P、V
参考答案：
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相关题目
【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
③
都会增大
【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（）
①
同时为正弦波
②
同为尖顶波
③
不会同时为正弦波
【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】
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】
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()
①
甲车间
②
乙车间
③
两个车间相同
④
无法作比较
【单选题】
下图所示网络中，f点发生三相短路时，关于短路点右侧网络中的电流正确的说法是（）。<imgsrc="http://wljy.whut.edu.cn:80/uploadfiles/kindeditorAttached/image/20191205/20191205075635_277.png"alt=""/>
①
不存在电流
②
过渡过程中存在电流
③
电流始终存在
【单选题】
设总体<imgwidth="14"height="14"v:shapes="_x0000_i1273"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image333.png">服从泊松分布：<imgwidth="217"height="40"v:shapes="_x0000_i1274"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image356.png">，其中<imgwidth="32"height="18"v:shapes="_x0000_i1275"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image358.png">为未知参数，<imgwidth="86"height="22"v:shapes="_x0000_i1276"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image336.png">为样本，记<imgwidth="84"height="40"v:shapes="_x0000_i1277"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image360.png">，则下面几种说法错误的是（）
①
<imgwidth="14"height="18"v:shapes="_x0000_i1278"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image362.png">是<imgwidth="12"height="18"v:shapes="_x0000_i1279"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image364.png">的无偏估计
②
<imgwidth="14"height="18"v:shapes="_x0000_i1280"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image362.png">是<imgwidth="12"height="18"v:shapes="_x0000_i1281"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image364.png">的矩估计
③
<imgwidth="14"height="14"v:shapes="_x0000_i1282"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image365.png">是<imgwidth="35"height="20"v:shapes="_x0000_i1283"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image367.png">的矩估计
④
<imgwidth="14"height="20"v:shapes="_x0000_i1284"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image368.png">是<imgwidth="12"height="37"v:shapes="_x0000_i1285"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image370.png">的矩估计
【单选题】
设总体<imgwidth="14"height="14"v:shapes="_x0000_i1259"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image333.png">的分布中带有未知参数<imgwidth="12"height="14"v:shapes="_x0000_i1260"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image334.png">，<imgwidth="86"height="22"v:shapes="_x0000_i1261"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image336.png">为样本，<imgwidth="29"height="26"v:shapes="_x0000_i1262"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image338.png"><imgwidth="109"height="26"v:shapes="_x0000_i1263"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image340.png">和<imgwidth="146"height="26"v:shapes="_x0000_i1264"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image342.png">是参数<imgwidth="12"height="20"v:shapes="_x0000_i1265"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image343.png">的两个无偏估计，若对任意的样本容量<imgwidth="12"height="14"v:shapes="_x0000_i1266"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image345.png">，若<imgwidth="12"height="26"v:shapes="_x0000_i1267"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image346.png">为比<imgwidth="12"height="26"v:shapes="_x0000_i1268"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image347.png">有效的估计量，则必有（）
①
<imgwidth="95"height="26"v:shapes="_x0000_i1269"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image348.png">
②
<imgwidth="95"height="26"v:shapes="_x0000_i1270"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image350.png">
③
<imgwidth="86"height="26"v:shapes="_x0000_i1271"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image352.png">
④
<imgwidth="86"height="26"v:shapes="_x0000_i1272"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image354.png">
【单选题】
设<imgwidth="12"height="14"v:shapes="_x0000_i1185"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image253.png">个随机变量<imgwidth="86"height="22"v:shapes="_x0000_i1186"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image239.png">是独立同分布，<imgwidth="164"height="42"v:shapes="_x0000_i1187"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image255.png"><imgwidth="32"height="20"v:shapes="_x0000_i1188"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image257.png"><imgwidth="115"height="42"v:shapes="_x0000_i1189"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image259.png">，则下列结论中，正确的是（）
①
<imgwidth="12"height="14"v:shapes="_x0000_i1190"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image261.png">是<imgwidth="12"height="12"v:shapes="_x0000_i1191"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image263.png">的无偏估计量
②
<imgwidth="12"height="14"v:shapes="_x0000_i1192"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image261.png">是<imgwidth="12"height="12"v:shapes="_x0000_i1193"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image263.png">的极大似然估计量
③
<imgwidth="12"height="14"v:shapes="_x0000_i1194"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image261.png">是<imgwidth="12"height="12"v:shapes="_x0000_i1195"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image263.png">的极大似然估计量
④
<imgwidth="12"height="14"v:shapes="_x0000_i1196"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image261.png">是<imgwidth="12"height="12"v:shapes="_x0000_i1197"src="http://wljy.whut.edu.cn:80/uploadfiles/word/xxdsb11.files/image263.png">的极大似然估计量
【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">
随机题目
【单选题】
静脉注射免疫球蛋白（IVIG）调节Th17/Treg具体表现为
①
IVIG促进Treg细胞增殖及相关细胞因子表达
②
IVIG抑制Th17细胞及相关因子增殖发育
③
IVIG降低Th17/Treg细胞比值，升高Treg，降低Th17
④
IVIG促进免疫耐受
⑤
以上均是