小灯泡I-U图像是非线性的,与之相关试题频繁出现.文章分析了学生解题困难的原因,并对几道典型试题作了较详尽的解析,总结出了解题方法. The light bulb I-U image is non-linear, and related questions frequently appear. The article analyzes the reasons for students’ difficulty in solving problems, and makes a detailed analysis of several typical test questions, and summarizes the methods for understanding problems.