a temporary magnet made by coiling wire around an iron core; when current flows in the coil the iron becomes a magnet
electromagnet详细解释
e.lec.tro.mag.net n.（名词）A magnet consisting essentially of a coil of insulated wire wrapped around a soft iron core that is magnetized only when current flows through the wire.电磁体：一种磁体，主要由绝缘线圈缠绕的一个软铁芯子组成，只有当电流通过线圈时芯子才被磁化
