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我们在进行电磁感应教学时遇到这样一道题,如图1所示,一只粗细均匀的金属环,其电阻为R,将它套在变压器的铁芯上作为副线圈,当环中出现图示的感生电流I时,则AB间的电势差是多少?(图中A、B、C三点把环等分为三段) 这道题涉及到涡旋电场问题,师生中存在两种截然不同的看法。第一种观点认为此题根本不存在电势问题,即不能引进电势问题,其理由是圆环中存在的是涡旋电场,由场理论可知,涡旋电场的电力线是闭合的,即(?)E旋·dl(?)0,由此可知,涡旋电场不是势场,不能引入电势概念。(注:《中学物理教学参考》1989年第二期p.15“电学中
We encountered such a problem when conducting electromagnetic induction teaching. As shown in Fig. 1, a uniform metal ring with a resistance of R was placed on the core of the transformer as a secondary coil. When the induced current I is shown, what is the potential difference between AB? (A, B, and C in the figure divide the ring into three equal parts) This question involves the vortex electric field problem, there are two kinds of teachers and students Different views. The first view is that there is no potential problem at all in this issue, that is, the potential problem cannot be introduced. The reason is that the eddy current field exists in the ring. It can be known from the field theory that the power line of the vortex field is closed, that is, (?) E rotation dl (?) 0, it can be seen that the vortex electric field is not a potential field, can not introduce the concept of potential. (Note: “Physical Education in Middle School Reference” 1989, second issue, p.15, "Electricity