依据磁感线方向、导体运动方向及感应电流方向的一个原始对应图,判定上述三个方向中的一个或两个发生变化后,剩余的那个方向的情况,是电磁感应部分常见的一类问题。本文介绍一种借助数学运算法则来分析处理这类问题的方法。 According to an original correspondence diagram of the magnetic line of direction, the conductor movement direction and the induced current direction, after determining whether one or two of the above three directions have changed, the remaining direction is a common problem in the electromagnetic induction section. . This article describes a method that uses mathematical algorithms to analyze and deal with such problems.