电磁感应的实质是利用磁场产生电的现象,产生的感应电流既有大小又有方向,法拉第电磁感应定律很好地解决了电流大小的问题,感应电流方向的判断则要通过楞次定律加以解决.如何才能学好楞次定律呢?学生可以借助我精心设计的问题来掌握楞次定律.首先观察有趣的小实验,让学生感受物理的真实性、趣味性,从而激发出他们听课的热情. The essence of electromagnetic induction is the use of magnetic field to generate electricity. The induced currents have both magnitude and direction. Faraday’s law of electromagnetic induction solves the problem of current size well, and the direction of induced current must be solved by Lenz’s law. How can we learn the Lenz’s law? Students can use my well-designed problems to master the Lenz’s Law. First, observe interesting little experiments and let students feel the authenticity and interest of the physics so as to stimulate their enthusiasm for lectures.