file:08看规律写关系式.mp4 file:07探究实验.mp4 file:03伏安法测电阻.mp4 file:02凸透镜成像规律.mp4 file:25电功率之字母问题.mp4 file:22多档位电热器.mp4 file:21比较额定功率和实际功率.mp4 file:20照顾最小原则.mp4 file:19变化量问题.mp4 file:17电路故障分析.mp4 file:15机械效率公式选择.mp4 file:24电磁感应.mp4 file:04能源的可持续发展.mp4 file:04越来越宽的信息之路.mp4 file:03无线电广播信号的发射和接收.mp4 file:01现代顺风耳―电话.mp4 file:09左手定则与右手定则的辨析.mp4 file:08磁场对通电导线的作用、电动机.mp4 file:07电磁继电器的构造及作用.mp4 file:06电磁铁及影响电磁铁磁性强弱的因素.mp4 file:04奥斯特实验（电流的磁效应）.mp4 file:01磁现象及磁极间相互作用.mp4 file:04家庭电路中电流过大的原因.mp4 file:02测电笔的结构与使用.mp4