一、规律探索问题1在图1所示的串联电路中,电源电压U保持不变,闭合开关S后,在滑动变阻器的滑片P从图中所示位置A滑到位置B的过程中,定值电阻R1、R2两端的电压变化量与阻值有什么关系?分析:设滑片P在位置A时,电路中的电流为IA,则R1、R2两端的电压分别为UA1=IAR1、UA2=IAR2.向右 First, the law to explore the problem 1 In the series circuit shown in Figure 1, the power supply voltage U remains unchanged, close the switch S, slide the varistor slide P from the position A shown in the figure to the process of the position B, What is the relationship between the value of the voltage change across the constant-value resistors R1 and R2 and the resistance? Analysis: Let the current in the circuit be IA when the slider P is in position A. Then the voltage across the R1 and R2 is UA1 = IAR1, UA2 =IAR2. Right