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.

將鐵氧體棒放置在垂直管的底端。向纏繞在其下端的細線線圈施加頻率與桿的固有頻率相同的交流電信號。 將一個小球放在桿的頂部，會觀察到小球彈跳現象。 解釋并探究這一現象。