有关电表示数变化的判定问题，在近几年中考试题中常有出现．这类题目不需要学生做繁琐的定量计算，而是要求学生运用学过的有关知识进行定性的讨论，主要考察学生综合应用知识的能力．那么，怎样快速解答此类题目呢？本人根据多年的教学经验总结了以下判定方法．首先，弄清电 The question of the change of the number of electrical representations has often appeared in examination questions in recent years. Such questions do not require students to do tedious quantitative calculations, but require students to use the knowledge they have learned to conduct qualitative discussions. They mainly examine the students’ ability to apply comprehensive knowledge. So, how to answer such questions quickly? According to my many years of teaching experience, I summarized the following methods of determination. First, find out