“焦耳定律实验”是初中物理教材中非常重要的验证性演示实验 ,教材中的做法是在两只分别放有不同阻值的电阻丝烧瓶中装满煤油 ,通过加热后 ,煤油温度升高、体积膨胀 ,使煤油在玻璃管中上升 ,来确定电流产生的热量跟电流、电阻和通电时间的关系。以此验证 :Ｑ =Ｉ2 Ｒｔ.(如图 “Joule’s Law Experiment” is a very important demonstration demonstration experiment in junior middle school physics textbooks. The practice in the textbook is to fill kerosene in two resistance wire flasks with different resistance values. After heating, the temperature of kerosene increases. The volume expansion causes kerosene to rise in the glass tube to determine the relationship between the heat generated by the current and the current, resistance, and energization time. To verify this: Q = I2 Rt. (Figure