额定功率与实际功率在初中物理中是个难点,讲清实际功率与额定功率间的关系,一方面可加深理解电功率的含义,另一方面可给解题带来方便.现根据电功率的定义、欧姆定律及串联电路的电阻特点推导出用电器的实际功率与额定功率间的两个关系及简单应用. The rated power and the actual power are difficult in the junior middle school physics. To clarify the relationship between the actual power and the rated power, one can deepen the understanding of the meaning of the electric power, and on the other hand, it can bring convenience to solving problems. According to the definition of electric power, ohms The law and resistance characteristics of the series circuit deduces the two relations between the actual power and the rated power of the appliance and its simple application.