双管对比式楞次定律演示装置

Double barrel demonstrator of Lenz law

利用圆柱形强磁铁在铜管中下落并与同尺寸圆柱形铁块自由下落相对比以验证感应磁场对强磁铁的阻碍作用,再利用螺线管配合发光二极管演示强磁铁进出螺线管时感应电流方向的变化,从两方各面验证了楞次定律.另外,利用本装置还可测量闭合回路中的感应电流等物理量.装置结构简单且可拆卸,具有组装快捷,操作方便等特点.

This paper presents the improvement scheme of a Lenz law demonstrator aimed to solve some problems of the current instruments. The dropping process of a powerful magnet in a copper tube is compared with that of an iron bulk with the same size and shape to verify the resisting effect of an induced magnetic field to the magnet. The directions of an induced current in a solenoid are visualized using two groups of light-emitting diodes when the powerful magnet passes through the solenoid.