一、问题的提出交流电的有效值是高中物理教学中一个十分重要的概念,既是教学中的重点和难点,也是高考的热点.现行高中《物理》(必修)第二册第113面对交流电的有效值是这样定义的:“交流的有效值是根据电流的热效应来规定的.让交流和直流通过同样阻值的电阻,如果它们在·同·一 First, the issue of the effective value of AC is a very important concept in high school physics teaching, is not only the focus and difficulty in teaching, but also a hot spot of the college entrance examination. The current high school “Physics” (required) in the second volume 113th face of the AC The effective value is defined as follows: "The effective value of the AC is regulated according to the thermal effect of the current. Let the AC and DC pass through the resistance of the same resistance if they are in the same