Series and Parallel Circuits | 串联与并联电路

📚 Series and Parallel Circuits | 串联与并联电路

Electric circuits can be connected in two main ways: series and parallel. Knowing how current, voltage and resistance behave in each type helps you predict whether lamps will glow brightly, why one broken bulb can affect a whole circuit, and how homes are wired safely.

电路主要有两种连接方式：串联和并联。了解电流、电压和电阻在每种连接中的表现，有助于你预测灯泡的亮度、为什么一个灯泡损坏会影响整个电路，以及家庭电路如何安全布线。

1. Circuit Basics and Symbols | 电路基础与符号

A complete circuit needs a source of electrical energy, such as a cell or battery, conducting wires, and components like lamps, switches, resistors, ammeters and voltmeters. We draw circuits using standard symbols so that anyone can read the diagram without needing a realistic picture.

一个完整电路需要电源（如电池）、导线以及灯泡、开关、电阻、电流表和电压表等元件。我们使用标准符号绘制电路，这样任何人都能看懂电路图，而不需要实物图。

A cell provides a push of voltage. A battery is two or more cells joined together. An open switch breaks a circuit; a closed switch completes it.

电池提供电压推动。电池组是由两个或多个电池组成的。断开的开关会切断电路；闭合的开关会接通电路。

2. What Is a Series Circuit? | 什么是串联电路？

In a series circuit, components are connected one after another in a single loop. Electric current has only one path to follow from the positive terminal of the cell around the circuit and back to the negative terminal.

在串联电路中，元件一个接一个地连接成一个回路。电流从电池正极出发，围绕电路流回负极，只有一条路径可走。

Because there is only one path, if one component breaks or a switch is opened, the whole loop is broken and all components stop working.

由于只有一条路径，如果一个元件损坏或开关断开，整个回路就会中断，所有元件都会停止工作。

3. What Is a Parallel Circuit? | 什么是并联电路？

In a parallel circuit, components are connected on separate branches between the same two points of the circuit. Each branch provides its own path, so the circuit contains more than one loop for current.

在并联电路中，元件连接在电路两个相同点之间的独立支路上。每条支路都有自己的路径，因此电路包含多个电流回路。

If one branch is switched off or broken, current can still flow through the other branches. This independent operation is a major advantage of parallel circuits.

如果一条支路被关断或损坏，电流仍可通过其他支路流动。这种独立工作的特性是并联电路的一大优势。

4. Current in Series and Parallel | 串联与并联中的电流

Current is the rate of flow of electric charge, measured in amperes (A). In a series circuit there is only one path, so the current is exactly the same at every point in the loop.

电流是电荷流动的速率，单位是安培 (A)。在串联电路中只有一条路径，因此回路中各点的电流完全相同。

I₁ = I₂ = I₃

In a parallel circuit, the total current from the supply splits between the branches. The sum of the branch currents equals the total current, and the branch with lower resistance takes a larger share.

在并联电路中，来自电源的总电流在各支路间分配。各支路电流之和等于总电流，电阻较低的支路获得较大的电流。

I_total = I₁ + I₂

5. Voltage in Series and Parallel | 串联与并联中的电压

Voltage is the energy transferred per unit charge, measured in volts (V). In a series circuit the supply voltage is shared between the components in the loop. The individual voltages add up to the total voltage.

电压是每单位电荷转移的能量，单位是伏特 (V)。在串联电路中，电源电压在回路中的元件之间分配。各元件电压之和等于总电压。

V_total = V₁ + V₂

In a parallel circuit, every branch is connected directly to the supply, so each branch receives the full supply voltage. Identical lamps in parallel therefore glow at normal brightness.

在并联电路中，每条支路都直接与电源相连，因此每条支路都获得全部电源电压

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