《变阻器》内容是初中电学的难点之一,也是学习欧姆定律、电路分析和动态变化等重点电学知识的基础,其学习效果直接影响对后面电学知识的探究和理解,起着承上启下的关键作用。 “Varistor” content is one of the difficulties of junior high school, but also the basis for learning the important electrical knowledge such as Ohm’s law, circuit analysis and dynamic change. Its learning effect directly affects the exploration and understanding of the latter electrical knowledge and plays a key role in bearing on and off.