We know from the principles of physics concerning electromagnetic induction that an electrical current always has an associated magnetic field. 我們從有關(guān)電磁感應的物理學(xué)原理獲知，電流總是要有一個(gè)相關(guān)的磁場(chǎng)的。
Because the core current is somewhat symmetrical around the axis of rotation, the associated magnetic field is similar to that of a bar magnet. 因為地核流在旋轉軸周?chē)嬖谥?zhù)一些對稱(chēng)，所以相關(guān)的磁場(chǎng)與棒磁鐵的磁場(chǎng)相似。
