在九年义务教育三年制初级中学教科书物理第二册（人民教育出版社）第九章的“电功和电功率”的“电功”一节教学中，有一个研究电流做功的多少跟哪些因素有关的演示实验。由于电流做功看不见，摸不着，学生缺乏这方面的感性认识，所以该实验以初二做功的知识为桥梁，将电流做 In the nine-year compulsory education three-year primary school textbook physics second volume (People’s Education Press) chapter nine “electric power and electric power” in the “electricity” section, there is a study of how much and what Factors related to the demonstration experiment. Because the current work cannot be seen and cannot be touched, the students lack the perceptual knowledge in this respect. Therefore, the experiment uses the knowledge of the second year as a bridge to make currents.