High in the polar regions, the lines of magnetic force point almost straight upwards.
在极地的高空，磁力线几乎是垂直指向上方。
When a charged particle is in a magnetic field, it tends to travel along that field's lines of force, spiralling as it goes.
当一个带电微粒在磁场中时，它会倾向于沿着磁力线螺旋运动。
I say "relatively" Because charged particles will experience a retarding force if they travel along magnetic field lines that converge.
我说“比较”，是因为当带电粒子沿著逐渐汇聚的磁力线方向运动时，会感受到一股迟滞力。
应用推荐