物理学中的许多概念 ,都是从定量分析与被研究概念相关的物理量的比值关系定义的 ,注重这些概念的教学 ,对促进学生正确理解概念 ,了解物理学的研究方法 ,会起到事半功倍的作用 .1　为什么要用比值定义物理量我们先看电场强度的定义过程 .在图 1所示的电场中的同一点 ,分别放置 Many of the concepts in physics are defined by the relationship between the quantitative analysis and the ratio of physical quantities related to the concept being studied. Paying attention to the teaching of these concepts will promote students’ understanding of concepts and understanding of physics research methods, which will do more with less. Function.1 Why use the ratio to define the physical quantity? Let’s look at the definition process of the electric field strength. At the same point in the electric field shown in Fig. 1, they are placed separately.