一、教学内容分析在初中物理“串联电路的电阻”一节的教学中 ,串联电路总电阻的计算公式是教学的重点 ,用等效观点分析串联电路是教学的难点 .为使学生更好地掌握教学的重点与难点 ,加深对串联电路总电阻的认识 ,多种初中教材中都安排了对插孔式和旋钮式电阻箱的介绍 ,并设计 First, the teaching content analysis In the junior middle school physics “resistor of series circuit” teaching, the calculation formula of the total resistance of the series circuit is the focus of teaching, using the equivalent point of view to analyze the series circuit is difficult to teach. To make students better Grasp the key and difficult points of teaching, deepen the understanding of the total resistance of the series circuit, and arrange the introduction of the jack type and knob type resistance box in a variety of junior high school textbooks and design