circuits. These are a couple of different circuit diagrams. Remember this stands for

電路。這是幾個不同的電路圖。請記住，這代表

a battery and each of those stand for a resistor. And so this would be a series circuit. Remember

一個電池，每個電池代表一個電阻。這就是一個串聯電路。記住

it's a closed circuit, so there's a loop where electricity can flow the whole way around.

它是一個閉合電路，是以有一個迴路，電力可以一直在迴路中流動。

And then we have three resistors. And so the electricity that goes through this has to

然後我們有三個電阻。是以，通過這裡的電流必須

go through these as well. If we look at this one, this is one battery connected to three

我們也來看看這些。如果我們看一下這個，這是一個電池連接到三個

resistors as well, but they're parallel to one another. In other words there's three

電阻器，但它們彼此平行。換句話說，有三個

loops that that electricity can take and so we call that a parallel circuit. Now the first

是以，我們稱之為並聯電路。現在，第一個

time you look at a series and a parallel circuit when it's actually connected, there's some

當你觀察串聯和並聯電路時，它們實際上是連接在一起的。

stuff that's not super intuitive. In other words there's some weird stuff that takes

不是超級直觀的東西。換句話說，有一些奇怪的東西需要

place. But once you really understand what's going on in both a series and a parallel circuit,

地方。但是，一旦你真正理解了串聯和並聯電路中發生的事情，你就會發現它們之間的區別、

you'll do much better. And so today I want to show you basically a parallel and a series

你會做得更好。所以，今天我要向大家展示的基本上是並聯和串聯

circuit, a few demonstrations. And I'm going to be using the Circuit Construction Kit.

電路，進行一些演示。我將使用電路構造套件。

This is at phet.colorado.edu and I would encourage you to go there and play around with it. It's

該網站位於 phet.colorado.edu，我鼓勵大家去那裡玩一玩。這是

the best way to learn about electricity is to actually play around with it. Okay. So

學習電的最好方法就是實際玩一玩。好的

right here we've got two different loops. This one, this would be a battery right here.

這裡有兩個不同的迴路這個是電池

It's a 9-volt battery. This is an ammeter which is going to measure the amps. We've

這是一個 9 伏電池。這是一個電流表，用來測量安培數。我們已經

then got wires connected to a light bulb back to a switch and then back to the battery again.

然後把電線連到燈泡上，再連到開關上，最後再連到電池上。

And so this would be a series circuit because electricity is going to flow is this direction

是以，這將是一個串聯電路，因為電流將沿著這個方向流動

through the battery and then back, through the bulb and then back again. And so what

通過電池再返回，通過燈泡再返回。所以

I turn it on we can see that electrons are flowing. We've got 0.90 Amps and then it's

打開電源，我們可以看到電子正在流動。我們有 0.90 安培，然後是

running through a light bulb. And so these rays around the outside of the light bulb

穿過燈泡。是以，燈泡外部的這些光線

show you how much light is being given off from that. And so the first thing I'd like

讓你看看有多少光從那裡發出。是以，我想做的第一件事就是

to do, let me turn that off for just a second. So let me open that circuit for a second,

讓我先把它關掉。讓我先打開電路、

is kind of get a sense for how much electricity is coming out or how much current is flowing

可以感覺到有多少電能流出，或有多少電流流過

through there and how much light are we getting off of that. And now I'm going to add another

我們能從那裡獲得多少光線？現在我要再加一個

light bulb and I'm going to put it in series. So let me add another light bulb here, and

燈泡，我要把它串聯起來。所以，讓我在這裡再加一個燈泡，然後

I have to break this with a junction and let me connect to both sides of that. And let

我必須用一個路口來打破這個局面，讓我連接到路口的兩邊。讓

me move it down so it looks a little better. Okay. So now we've got two light bulbs, we've

我把它往下移一點 這樣看起來會好一點好了，現在我們有兩個燈泡了

got the same battery, you kind of remember how much light we were getting out of it before

你可能還記得，在使用這塊電池之前，我們用它發出了多少光？

and you remember the speed. And so let's turn this one on now. Okay, so in a series circuit

你記得速度現在讓我們把這個打開。好了，在串聯電路中

what we have now is those two bulbs are not as bright and the reason why, if you remember

現在的情況是，這兩個燈泡沒有那麼亮，原因是，如果你還記得

how much speed we were getting, how much current we were getting, remember it was 0.90 amps.

我們的速度有多快，電流有多大，記得是 0.90 安培。

And so in a series circuit, if we add more resistance we're going to decrease the amount

是以，在串聯電路中，如果我們增加更多電阻，就會減少

of current. And as a result we are going to have dimmer light bulbs. And so the current

的電流。是以，我們的燈泡會越來越暗。是以電流

is going to be the same through every component in a series circuit. And so the other thing

通過串聯電路中的每個元件都是一樣的。是以

about a series circuit is let me try, let me remove this. So let me split the junction.

關於串聯電路，讓我來試試，讓我把這個拆掉。所以，讓我來拆分接點。

Okay. So when I split the junction there I cut that wire and so it wasn't connected anymore

好吧，當我把接合處分開時，我切斷了那根電線，所以它不再連接了

and so both bulbs went out. And so the two things you should learn number 1 is that

於是兩個燈泡都熄滅了。是以，你應該學會兩件事，第一是

in a series circuit all of them have to be working for a current to flow and the second

在串聯電路中，所有的電路都必須工作，電流才能流動，而第二個

thing is that they all have the same amount of current. Volts is another thing. And so

問題是它們的電流都是一樣的。伏特是另一回事。是以

let's add a volt meter as well. So if we add a voltmeter, this is a 9-volt battery, if

讓我們再加上一個電壓表。如果我們加上一個電壓表，這是一個 9 伏的電池，如果

I look on either side of the light bulbs we'll find that the volts are 9.00 volts. If I move

我查看燈泡兩側的電壓，發現電壓為 9.00 伏。如果我移動

this lead over here, this electrode over here, we find that it's 4.50 volts. And then if

我們發現電壓是 4.50 伏。如果

I shift both of them to this side of that light bulb is 4.5 as well. And so the sum

我把它們都移到燈泡這邊，也是 4.5。是以總和

of the volt or the voltage drop between the two components in that are going to equal

的電壓或兩個元件之間的壓降將等於

the volts that we have for the whole thing. And so it's 9 volts, but then each of those

我們整個系統的電壓。是以，它的電壓是 9 伏，但每一

bulbs is going to be a drop of 4.5 volts. So we have 9 volts and then we have 0 volts

燈泡的電壓將下降 4.5 伏。是以，我們有 9 伏，然後是 0 伏

when we get to the other side. So let's get rid of that volt meter and let me turn this

當我們到達另一邊時所以，讓我們把電壓表扔掉，讓我把這個

one off. And so let's return that for a second. Get a sense of how much light we are getting

一個關閉。讓我們先回到這裡。瞭解我們獲得了多少光線

from these two light bulbs, and we have 0.45 Amps. And now we're going to look down here

這兩個燈泡的電流為 0.45 安培。現在我們往下看

at a parallel circuit. And so a parallel circuit there are two parallel pathways. In other

並聯電路是以，一個並聯電路有兩條並聯路徑。在其他

words there's a wire that goes through this bulb and a wire that goes through this bulb.

話說有一根電線穿過這個燈泡，還有一根電線穿過這個燈泡。

And so when I turn this on there's a clear difference between the two. And the first

所以當我打開它時，兩者之間有明顯的區別。第一個

time I saw this it was totally confusing to me. In other words these two light bulbs are

當我看到這個的時候，我完全糊塗了。換句話說，這兩個燈泡是

as bright as that one light bulb was before, when it wasn't in series. And so the first

就像那隻燈泡在沒有串聯時一樣亮。是以，第一個

thing that should stand out to you is that these two bulbs are as bright as that one

最突出的一點是，這兩個燈泡和那個燈泡一樣亮

bulb before it was hooked up in series. And so another thing that's happening is that

在串聯之前的燈泡。是以發生的另一件事是

we actually have way more amps moving through this. And so you can see that the electrons

我們實際上有更多的電流通過這裡。是以，你可以看到電子

are moving more quickly. And so the difference between a series circuit and a parallel circuit

移動得更快。是以，串聯電路和並聯電路的區別在於

is that the current is actually increased. Remember when we had, let's go back and remove

是電流實際上增加了。還記得嗎，讓我們回到過去，移除

this and just connect it together, so remember here we had 0.90 amps for one light bulb,

然後把它連接起來，記得這裡一個燈泡的電流是 0.90 安培、

but here we now have 1.8 amps. In other words the electricity is actually flowing faster.

但現在我們的電流是 1.8 安培。換句話說，電流實際上流動得更快了。

Why is that? Well here there is the current of this thread and there's the current of

為什麼會這樣？這裡有這條線的水流，也有那條線的水流。

this branch and the two currents together are going to sum up to this current. And so

這兩個電流相加就是這個電流。是以

before when we were saying the voltage dropped in each of those sums up to the voltage of

我們之前說過，每個電壓降的總和會達到

the battery, well in a parallel circuit those two pathways, in other words those two currents

在並聯電路中，這兩個通路，換句話說，這兩個電流

are going to sum up to the current of that, the whole branch. Another thing that happens

的總和，即整個分支。另一種情況

in a parallel circuit, let's kind of remove this light bulb, and so remember when I removed

在並聯電路中，讓我們移除這個燈泡，記得當我移除它時

a series light bulb the whole thing went out, but in a parallel circuit when I remove one

在串聯電路中，燈泡會全部熄滅，但在並聯電路中，當我取下一個燈泡時

of those light bulbs, the other one keeps moving. Now you should've seen that when I

而另一個燈泡卻一直在動。現在你應該看到了，當我

removed that light bulb the Amps dropped down to 0.90 and electricity isn't flowing through

取下燈泡後，安培數下降到 0.90，電力無法流過

this side. But by hooking it up this way we've now got electricity or a path for electricity

這邊但這樣連接起來，我們就有了電或通電的路徑

to go. When I was a kid I remember we had a string of light bulbs that were hooked up

去。我記得小時候，我們家有一串燈泡，這些燈泡連接著

in series and it was the most annoying light bulb strand that you could have for Christmas

串聯起來，是聖誕節最惱人的燈泡串

lights because if you ever had one bulb go out, on a series circuit, then the whole thing

因為在串聯電路中，如果有一個燈泡壞了，那麼整個電路就會

was broken all the way down. So you had to search through that string of lights until

一直都是壞的。是以，你必須在燈串中尋找，直到

you found the one that was burnt out. Now they use parallel circuits and the reason

你找到了燒壞的那一個。現在他們使用並聯電路，原因是

they do that is you don't get that drop in current with each bulb. And the other thing is that you

這樣，每個燈泡的電流就不會下降。還有一點就是

can have a break in one of the bulbs and the other ones are all going to work. And so that's

如果其中一個燈泡壞了，其他燈泡也能正常工作。這就是

kind of an introduction to series and parallel circuits. Remember in a series circuit the

算是對串聯電路和並聯電路的介紹。請記住，在串聯電路中

current is going to be the same through every part of that loop. But in a parallel circuit

通過迴路各部分的電流將是相同的。但在並聯電路中

it's going to be the sum of the two will be the sum of the current through the whole circuit.

兩者之和將是通過整個電路的電流之和。

And the voltage drop if we add our voltmeter, in a parallel circuit it's going to be the

如果加上電壓表，並聯電路中的壓降將是

same along each thread. So remember this would be a 9.00 volt on this pathway, but it's also

每條線路都一樣。是以，請記住，這條通路上的電壓為 9.00 伏，但它也是

going to be a 9.00 volt on this pathway. And so you're not getting anything for free with

這條路上的電壓將達到 9.00 伏。是以，你不會免費得到任何東西。

a parallel circuit, you're actually going to go through more energy using this set up

並聯電路，使用這種設置實際上會消耗更多能量

then you would over here because you're gathering more amps. So that's parallel and series circuit

然後你會在這裡，因為你收集了更多的安培數。這就是並聯和串聯電路

and I hope that's helpful.

希望對你有所幫助。