.在额定频率为50Hz的电网中，用于核电机组的四极同步发电机，其同步转速为（   ）。

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69454' and id < 4497940 and id<>'4497940' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69454' and id > 4497940 and id<>'4497940' order by id asc limit 5