题目内容
额定电压为110V,阻值为1000Ω的灯泡,为了接于220V电源,分别串1000Ω电阻和1735Ω感抗使用,如图所示。图(a)的效率和图(b)的效率一样。( )
试卷相关题目
SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69315' and id < 4487634 and id<>'4487634' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69315' and id > 4487634 and id<>'4487634' order by id asc limit 5