自制电力线演示器何钟（河北怀来县沙城中学０７５４００）高中物理中电力线概念比较抽象，学生难以理解．如果能够用图形把电场中各点场强的大小和方向形象地表示出来，就能使学生深刻地认识电场、电力线的概念．我们曾用购置的几套“电力线谱”（２３１４，涿县师范教学... Self-made power line demonstrator He Zhong (Shacheng Middle School, Huailai County, Hebei Province, 075400) The concept of power lines in high school physics is relatively abstract and difficult for students to understand. If we can graphically represent the magnitude and direction of the field strength at various points in the electric field, we can make students deeply understand the concepts of electric field and power line. We have used several sets of “power line spectrum” purchased (2314, Lixian teacher education ...