对称星形负载接于线电压为380V的三相四线制电源上，如图所示。当M点和D点同时断开时，U1为（     ）V。（0.5）

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69423' and id < 4495227 and id<>'4495227' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69423' and id > 4495227 and id<>'4495227' order by id asc limit 5