欧姆定律是研究电流、电压、电阻三个物理量间的变化关系.课本中的研究步骤是: 1.保持电阻不变,通过改变电压,观察电流的变化; 2.保持电压不变,通过变换电阻,观察电流的变化,从而得出了它们之间的关系. 研究过程用了控制变量法.步骤是: (1)、明确研究的问题中有多少个物理量,研究的对象是哪个物理量; Ohm’s law is to study the relationship between the three physical quantities of current, voltage, and resistance. The study steps in the textbook are: 1. Keep the resistance constant, observe the change of current by changing the voltage; 2. Keep the voltage constant, pass the conversion resistance Observe the changes in the current and thus the relationship between them. The research process uses the control variable method. The steps are: (1) Explicitly examine the number of physical quantities in the problem and which physical quantity is the object of the study;