电场中的电力线是很抽象的概念,须通过实验帮助学生建立形象的电力线模型。我们用光滑的腊线织成线网,其大小正好装入一只乒乓球,在结头处各系上一条约4厘米长的带色丝线(以下将此装置称网球),在网球上端装一个用铁丝弯成的钩子(如图1所示), The power line in the electric field is a very abstract concept. It is necessary to help students establish an image of the power line model through experiments. We used a smooth wax thread to woven into a wire mesh, the size of which fits into a table tennis ball. At the end of the knot, each line is tied with a 4 centimeter long colored silk thread (hereinafter referred to as tennis ball). A hook bent from wire (as shown in Figure 1),