论文部分内容阅读
全日制十年制学校高中课本下册在讲到“感生电流的方向、楞次定律”这一节时,提到如图1所示的一个实验。书中对这个实验的说明是:“用磁铁的任一极来接近闭合的A环,可以看到A环被磁铁推斥;移走磁铁,又可以看到A环被磁铁吸引。但是,用磁铁去接近或离开断开的B环时,B环都不运动。”(着重号是作者加图1的)并说,这一现象是符合能量守恒定律的。“ 这里说的符合能量守恒定律,是指:①当磁铁的一极移近闭合的A环时,A环里产生感生电流,表明有机械能转化成电能,即外力对A环做了功(A环被推斥);当磁铁的一极从A环移开,A环被吸
A full-time, 10-year high school textbook, referred to in the section “Direction of induced currents, Lenz’s law”, refers to an experiment as shown in Figure 1. The explanation of this experiment in the book is: ”Use any pole of the magnet to get close to the closed A ring, you can see that the A ring is being repelled by the magnet; remove the magnet and you can see that the A ring is attracted by the magnet. However, When the magnet is used to approach or leave the broken B-ring, the B-ring is not moving. "(The emphasis is on the author plus Fig. 1) and said that this phenomenon is in line with the law of conservation of energy. The law of conservation of energy, here, refers to: 1 When a pole of a magnet moves closer to the closed A-ring, an induced current is generated in the A-ring, indicating that mechanical energy is converted into electrical energy, that is, external forces do work on the A-ring. (A ring is repulsed); when the pole of the magnet moves away from ring A, ring A is sucked