Ball on Ferrite Rod

A ferrite rod is placed at the bottom end of a vertical tube. Apply an ac voltage, of a frequency of the same order as the natural frequency of the rod, to a fine wire coil wrapped around its lower end. When a ball is placed on top of the rod, it will start to bounce. Explain and investigate this phenomenon.

将铁氧体棒放置在垂直管的底端。向缠绕在其下端的细线线圈施加频率与杆的固有频率相同的交流电信号。 将一个小球放在杆的顶部，会观察到小球弹跳现象。 解释并探究这一现象。