发布时间:2025-01-31 08:49:05
①在磁体的外部,磁感线总是从磁体的N极出发回到S极,所以通电螺线管的右端为N极,左端为S极;
磁体A的左端为N极,右端为S极.
②根据安培定则,伸出右手,使大拇指指示螺线管的N极,则四指弯曲的方向为电流的方向,即电流由螺线管的左端流入,则电源的左端为正极,右端为负极.
如图所示:
窗帘长期关住可以挡墙角对窗户吗长期关窗帘可以挡住窗户对墙角的化解吗
2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05我要做滤水器 但是家里只有烧烤用的炭 那些炭怎么做成活性炭呢
2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05 2025-01-31 08:49:05