初中物理题目 ,大多是根据教材中的概念、公式、定理、定律进行解答的。在学习中 ,如果能总结出教材中没有明确的规律 ,就会给解题带来很多方便 ,提高解题的效率。下面举例说明。例 1　已知电阻R1与R2 的阻值之比是R1∶R2 =1∶3,如果将这两个电阻接在一电源上 ,接通电路 ,则两 Junior high school physics topics are mostly based on concepts, formulas, theorems, and laws in the textbooks. In the course of learning, if we can conclude that there is no clear rule in the textbook, it will bring a lot of convenience to solving problems and improve the efficiency of solving problems. The following is an example. Example 1 The ratio of the resistances of known resistors R1 and R2 is R1:R2 = 1:3. If the two resistors are connected to a power supply and the circuit is turned on, the two