用电流表和电压表测电源电动势和内电阻的实验是高中物理的一个重要实验,也是恒定电流一章的难点。同学们对教材中所给的测量电路图体会不深,认为把电流表放在干路中(如图1所示)和放在滑动变阻器的支路中(如图2所示)效果是一样的。下面我们从两种实验方法所产生的系统误差角度来加以论述。 Using ammeter and voltmeter to test the electromotive force and internal resistance of the experiment is an important experiment in high school physics, but also the difficulty of a chapter constant current. The students did not know enough about the measurement circuit diagram given in the textbooks. They thought that putting the ammeter on the trunk (as shown in Figure 1) and the slip on the slip rheostat (as shown in Figure 2) would be the same. In the following, we discuss the systematic errors produced by the two experimental methods.