初中物理教材(人教版)第二册第148页演示磁极间相互作用的实验,采用一条细绳悬挂一根条形磁铁,手抓另一根相同的条形磁铁去靠近它,以演示同名磁极互相排斥,异名磁极互相吸引。此实验在具体操作过中有如下不足:在实验时,用细绳悬吊着条形磁铁时,绳子本身产生扭矩力,使悬吊的条形 The junior high school physics textbook (PEP) Volume 2 Page 148 Demonstrates the interaction between magnetic poles, using a thin string to suspend a bar magnet, grab another same bar magnet to get close to it, to demonstrate the same name The magnetic poles are mutually exclusive and the magnetic poles of different names attract each other. This experiment has the following deficiencies in the actual operation: During the experiment, when the bar-shaped magnet is suspended with a string, the rope itself generates a torque force, so that the hanging bar