电路如图所示，ab两端的等效电阻为（   ）。

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69470' and id < 4499473 and id<>'4499473' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69470' and id > 4499473 and id<>'4499473' order by id asc limit 5