The field may be provided by permanent magnets or by electromagnets.外地可能提供的永磁材料,或由电磁铁.The rails of their Maglev train were made of about 100 magnets.他们所做的磁悬浮列车轨道采用了约100块磁铁.Magnets are used for the controller's attac...
We know about magnetism by the way magnets act.我们通过磁铁的作用知道磁性是怎么一回事.The N pole and S pole of two magnets will attract each other.两个磁体的N极和S极互相吸引.The entire ring has about 1000 magnets spaced at regular intervals.整个圆环由大约100...