做此实验时,经常会出现的故障是,当滑动触头D于AC线段上滑动时,电流计中总有电流通过,在AC线段中间,找不到平衡位置,只有在极端位置(图一中的A点或C点)电流计中的电流才为零,实验故障发生的哪里呢?现就以下两种情况作一些简要的分析讨论。 When doing this experiment, the fault that often occurs is that when the sliding contact D slides on the AC line segment, there is always current through the ammeter, and in the middle of the AC line segment, no equilibrium position can be found, only in the extreme position (Figure 1) In point A or point C, the current in the galvanometer is zero. Where does the experimental failure occur? We will briefly discuss and discuss the following two situations.