律师案源长远发展之道——解决中小型律所面临的十大课题.pptVIP

Lesson 2 Application of Ohm’s Law 学习目标： 掌握有关基本电路元素、电路结构和电学参量的专业词汇； 掌握简单的电路原理；理解欧姆定律中元件串并联的含义及电路中各参量之间的关系。 二. 课文翻译讲解 2、课文翻译讲解： How to monitor the brightness of a light in a circuit? Which segment decides the brightness of the light in the circuit, as shown in Fig2-1? We can see the brightness adjustable light anywhere in the market or in our home. Rotate the knob, the light will turn brilliant or turn dark. So when you rotate the knob, what has changed in the circuit? 如何调节灯的亮度？ 如图2-1所示，电路中哪部分决定灯的亮度？不论是家里还是在市场，我们都可以看见亮度可调的灯。当你旋转旋钮的时候，灯就会变亮或者变暗。那么当你旋转旋钮的时候，究竟改变了电路中的什么参数呢？ All electrical circuits fall into one of three classes: series circuits, parallel circuits, and seriesparallel circuits. A series circuit is one in which the current flows in a single continuous path and is of the same value at every point in circuit (Fig2-2). 所有的电路都可以归为三类：串联电路、并联电路以及串并联电路。串联电路是指这样一种电路：在这个电路里，电流在单一的连续的路径里流动，并且在这个电路的任何一个点，电流值都是一样的，如图2-2所示。  In a parallel circuit there are two or more current paths between two points in the circuit, as shown in Fig2-3.Here the current divides at A, one part going through R1, and the other part through R2, and combines at B to return to the battery。 而并联电路是指：在这个电路里，某两个节点之间，存在两个或者两个以上的回路，如图2-3，在这个电路里，电流在A点分流，一部分流经R1，一部分流经R2，最后在B点汇合，再回到电池中。 Fig2-4 shows series parallel circuits. There are two paths between points A and B as in the parallel circuit, and in addition there are two resistances in series in each branch of the parallel combination. The other example of series parallel arrangements appears in Fig2-5.The way in which the current splits to flow through the parallel branches is shown by the arrows. 图2-4所示的是串并联电路，并联部分在A点和B点之间有两个回路，此外，在每一个并联回路中，还串联了一个电阻。图2-5是串并联电路的另一个例子，图中已用箭头标出了电流的流动方向。 2.疑难解析 （1）All electrical circuits fall into one of three classes: series circuits, parallel circuits, and seriesparallel circuits. Fall into 1）落入，陷入，掉进： The boy fell into water and had to be pulled out at once. 2）盲目或无意中陷入(危险或不愉快的境地或状态)；进入(身心的某种状态，如昏迷、