验电器、静电计、电压表是研究电学知识的重要实验仪器,但对于这3种仪器在结构、作用方面的异同,多数学生并不十分清楚,在处理这3个仪器的有关问题中经常错误百出.例如认为“只要把验电器的金属箔换成金属指针就变成了静电计”,“验电器可以用来检验和比较不同带电体所带电荷量 Electroscope, electrometer, voltmeter is an important experimental instrument for the study of electrical knowledge. However, most students are not very clear about the similarities and differences in the structure and function of the three kinds of instruments. They are often mistakes in dealing with these three instruments For example, that "electrosurgical instruments can be used to test and compare the amount of charge carried by different charged bodies as long as the metal foil of the electroscope is replaced by a metal pointer