例谈测电阻的方法

• 作 者: 吴炘国
• 机 构: 湖北
• 出 处: 中学生理科月刊
• 发表日期: 2001年09期
• 关键词: 定值电阻 中考命题 综合考查 滑动变阻器 设计型实验 并联电路 伏安法 流关系 示数 新题型

“伏安法”测电阻是初中电学中重要的学生实验，也是各地中考命题的热点．近年来，各地中考物理的设计型实验题已跳出对教材中常规方法的考查，成为综合考查素质和能力的开放性的新题型。本文通过一例，结合同学们学过的串并联电路中的电流关系、电压关系及滑动变阻器的使用等知识，变换此实验中的某些器材和条件，根据不同要求，设计出几种特殊的测电阻的方法．

“Volt-Ampere” measuring resistance is an important student experiment in junior high school electricity, and it is also a hot spot in the propositions of local exams. In recent years, design-type experimental subjects in the physics of local examinations have jumped out of the examination of conventional methods in textbooks, and have become open-ended new questions for comprehensive examination of diathesis and competence. This article uses an example to combine the knowledge of the current relationship, the voltage relationship, and the use of a sliding rheostat in the series-parallel circuit learned by the students, transform some of the equipment and conditions in this experiment, and design several special measurements according to different requirements. Resistance method.