B1 中級 34 分類 收藏
開始影片後,點擊或框選字幕可以立即查詢單字
字庫載入中…
回報字幕錯誤
What is a candle flame really made of?
I am at the Palace of Discovery in Paris to do an experiment
that beautifully demonstrates the answers.
Ok so we're turning on an electric field here
and we see that the flame is spreading out.
Thats very cute,
it's like a butterfly.
And you can see that the flame
has two separate pieces to it now.
One is going towards the negative plate.
Those would be the positive ions,
and the negative ions will be going towards a positively charged plate.
So we see the flame kinda flattening out.
But if that didn't convince you
that flame contains ions,
then check part two of our experiment
where we compare the conductivity of a
flame to the connectivity of air,
which is normally a pretty good insulator.
It requires about 10,000 volts
to break down a centimeter of air.
So right now this plate is is about 20,000 V.
You see that the spark is only little,
but if I put it around the flame,
we will see if we can get a bigger spark happen.
Look at that, yeaaa!
Because the flame has those ions in it,
that means that we can break down
a greater distance of air.
This greater conductivity.
It's awesome! You love doing this, right?
A strong enough electric field
can actually extinguish the flame
but watch carefully what happens when the flame goes out.
Just like in the flame, the opposite charges in the smoke
are pulled in opposite directions.
Now while some may argue that a flame is not
truly a plasma because it's not hot enough
and it doesn't have a high enough density of ions,
one thing is for sure, it does contain ions
which have important electrical properties,
which can be demonstrated if you have a strong enough electric field.
提示:點選文章或是影片下面的字幕單字,可以直接快速翻譯喔!

載入中…

What's In A Candle Flame?

34 分類 收藏
林宜悉 發佈於 2020 年 3 月 29 日
看更多推薦影片
  1. 1. 單字查詢

    在字幕上選取單字即可即時查詢單字喔!

  2. 2. 單句重複播放

    可重複聽取一句單句,加強聽力!

  3. 3. 使用快速鍵

    使用影片快速鍵,讓學習更有效率!

  4. 4. 關閉語言字幕

    進階版練習可關閉字幕純聽英文哦!

  5. 5. 內嵌播放器

    可以將英文字幕學習播放器內嵌到部落格等地方喔

  6. 6. 展開播放器

    可隱藏右方全文及字典欄位,觀看影片更舒適!

  1. 英文聽力測驗

    挑戰字幕英文聽力測驗!

  1. 點擊展開筆記本讓你看的更舒服

  1. UrbanDictionary 俚語字典整合查詢。一般字典查詢不到你滿意的解譯,不妨使用「俚語字典」,或許會讓你有滿意的答案喔