Simple Circuits · 简单电路
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| circuit/ˈsɜːkɪt/ | 电路 | diàn lù |
| electromotive force/ɪˌlektrəʊˈməʊtɪv fɔːs/ | 电动势 | diàn dòng shì |
One battery, one bulb, one loop — and light
- Connect a battery to a bulb with two wires and the bulb glows.
- Break either wire and the light dies at once — the loop must be complete.
- A circuit 电路 is a closed path that lets charge flow from a source and back.
- Learn to read this simple loop and every complex circuit becomes approachable.
一节电池、一个灯泡、一个回路——就有了光
- 用两根导线把电池接到灯泡上,灯泡就亮了。
- 弄断任一根导线,光立刻熄灭——回路必须完整。
- 电路是一条闭合路径,让电荷从电源流出再流回。
- 学会读懂这个简单回路,每一个复杂电路都变得可以着手。
The parts of a circuit
- A source (battery or cell) supplies the energy, its voltage the "push".
- Wires carry the current with almost no resistance.
- Components (bulbs, resistors) use the energy the current delivers.
- A switch opens or closes the loop, turning the current on or off.
电路的组成部分
- 电源(电池或电池组)提供能量,它的电压就是"推力"。
- 导线几乎没有电阻地承载电流。
- 元件(灯泡、电阻)使用电流送来的能量。
- 开关断开或闭合回路,让电流开或关。
A single loop · 单个回路
Build a simple series circuit and see the same current flow through each part. · 构建简单的串联电路，观察相同电流流经每个部分。
For current to flow in a circuit, the loop must be: · 要使电路中产生电流，回路必须是：
A complete, closed loop is needed; any break stops the current. · 需要一个完整的闭合回路；任何断开都会导致电流停止。
What does a switch do in a circuit? · 开关在电路中起什么作用？
A switch opens (off) or closes (on) the circuit loop. · 开关打开（关闭）或闭合（开启）电路回路。
Select all · 所有 parts of a basic circuit. · 选择所有基本电路的组成部分。
A basic circuit needs a source, wires and a component. A magnet is not required. · 基本电路需要电源、导线和元件。不需要磁铁。
EMF: the battery's push
- A battery's electromotive force (EMF) 电动势 is the voltage it provides — the energy per unit charge.
- It "lifts" charge to a high potential, ready to flow round and deliver energy.
- The current is the same everywhere in a single unbranched loop.
- Energy is carried from the battery to the components and turned into light or heat.
电动势:电池的推力
- 电池的**电动势(EMF)**是它提供的电压——单位电荷的能量。
- 它把电荷"抬"到高电势,准备流动一圈去输送能量。
- 在单一不分支的回路中,电流处处相同。
- 能量从电池被带到元件,变成光或热。
The voltage a battery provides — its energy per unit charge — is called its . · 电池提供的电压——即单位电荷的能量——被称为其。
The electromotive force (EMF) is the battery's energy per unit charge. · 电动势 (EMF) 是电池的单位电荷能量。
In a single unbranched loop, the current is the same at every point. · 在单个无分支回路中，每一点的电流都相同。
With one path, the same current flows through every component. · 只有一条路径时，相同的电流流经每个元件。
Reading a circuit diagram
- Circuits are drawn with standard symbols: lines for wires, a pair of bars for a cell.
- Trace the loop from the + terminal, through each component, back to the −.
- If the loop is unbroken, current flows; a gap (open switch) stops it.
- This shorthand lets us plan and analyse circuits on paper before building them.
读电路图
- 电路用标准符号画:线表示导线,一对横杠表示电池。
- 从 + 端出发追踪回路,穿过每个元件,回到 −。
- 若回路不断,电流就流动;有缺口(开关断开)就停止。
- 这种速记让我们在动手之前就能在纸上规划和分析电路。
A circuit only works if the loop is complete. A single break anywhere — a loose wire, an open switch, a burnt-out bulb in series — stops all the current, not just at that spot. In a single loop the current is the same at every point.
电路只有在回路完整时才工作。任何地方的单个断口——松动的导线、断开的开关、串联中烧坏的灯泡——都会让所有电流停止,而不只是那一处。在单回路中,电流处处相同。
A bulb in a single-loop circuit burns out. What happens to the current elsewhere in the loop? · 单回路电路中的一个灯泡烧坏了。回路其他地方的电流会发生什么变化？
A break in the single loop stops all current, not just at the bulb. · 单回路的断开会阻止所有电流，而不仅仅是灯泡处。
A $6\ \text{V}$ battery is connected to a single bulb, and $2\ \text{A}$ flows.
- The current is $2\ \text{A}$ everywhere in the loop — the same leaving and returning to the battery.
- Open a switch anywhere and the current everywhere drops to zero.
一节 $6\ \text{V}$ 的电池接到单个灯泡上,有 $2\ \text{A}$ 流过。
- 电流在回路中处处是 $2\ \text{A}$——离开电池的和流回电池的相同。
- 在任何地方断开开关,处处的电流都降到零。
A circuit is a complete loop that lets current flow from a source (with its EMF) through wires and components and back. Break the loop anywhere and all current stops. In a single unbranched loop, the current is the same at every point.
电路是一个完整回路,让电流从电源(带其电动势)出发,穿过导线和元件再流回。任何地方断开回路,所有电流都停止。在单一不分支的回路中,电流处处相同。