题目内容
如图甲所示,在圆形线框的区域内存在匀强磁场,开始时磁场垂直于纸面向里.若磁场的磁感应强度B按照图乙所示规律变化,则线框中的感应电流I (取逆时针方向为正方向)随时间t的变化图线是( )
试卷相关题目
SQL Error: select id,body,options from ***_enewstiku_ where sourceid='15523' and id < 2637920 and id<>'2637920' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='15523' and id > 2637920 and id<>'2637920' order by id asc limit 5