闭合电路欧姆定律在电学中占有很重要的位置 ,新教材第 58面用了图 13- 5到图 13- 7三个图来说明这一定律 ,但就是没有介绍用演示实验来证实这一定律 .关于这一实验 ,一般学校实验室是用的原电池 ,由于内阻很小 ,实验很难成功 .笔者经过多年的教学试验 ,设计自制了一个实验演示 Closed-circuit Ohm’s law occupies a very important position in electricity. The 58th plane of the new textbook uses the three diagrams shown in Figures 13-5 to 13-7 to illustrate this law, but it does not introduce demonstration experiments to verify this law. About this experiment, the general school laboratory is the original battery, because the internal resistance is very small, the experiment is very difficult to succeed. After years of teaching experiments, the author designed an experimental demonstration