某三相50Hz异步电动机的额定转速RTN=980r/min。该电机的额定转差率是

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='30223' and id < 2444860 and id<>'2444860' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='30223' and id > 2444860 and id<>'2444860' order by id asc limit 5