“电功率”是初中物理电学部分的重点和难点,它几乎涉及电学的所有内容,知识综合性较强.各地中招考试中涉及电学的综合性试题大都落脚在对用电器电功率的考查上,重点考查电功率的概念、额定功率和实际功率的区别以及电功率的计算等. “Electrical power ” is the focus and difficulty of the physics part of junior high school physics, it involves almost all of the electrical content, knowledge is comprehensive and comprehensive.Everywhere in the examination involving the electrical comprehensive test mostly settled in the test of electrical power consumption , Focusing on examining the concept of electric power, the difference between rated power and actual power, and the calculation of electric power.