手电筒里的两节干电池用久了,灯泡发出暗淡的红光,这就是我们常说的“电池没电了”.有人为了节约,在手电筒里只换上一节新电池而与另一节旧电池搭配使用,这样的做法是否合理呢?为此笔者作了下面的实验.图1采用如图1所示的电路测电池的电动势和内电阻,测得新电池的电动势为E1=1. The two dry batteries in the flashlight have been used for a long time. The bulb emits a dim red light. This is what we often call “The battery is dead.” Some people have saved only one new battery in the flashlight to save money. The battery is used together, is this approach reasonable? For this reason, the author made the following experiment. Figure 1 uses the circuit shown in Figure 1 to measure the electromotive force and internal resistance of the battery, and the measured electromotive force of the new battery is E1=1.