赏析一道电磁学好题

Appreciating a good problem in electromagnetics

一道好的题目,应能够起到发散学生思维,整合各部分知识,并对以后的学习具有启发指导意义。在学习了安培力和洛伦兹力以后,我们可以与同学们一起研究讨论这样一道题目。

A good title,should be able to learn the knowledge,integration of each part,and has the inspiration significance to future learning. After learning the ampere force and Lorenz force,we can talk about such a topic with the classmates together.