Name: Conductors and Insulators | Physics | Khan Academy
Uploaded: 2022-07-19T03:00:48.000Z
Duration: 13 min 33 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

like all materials in the universe can be broken down

into a category of insulator, electrical insulator,

There are semi-conductors and super conductors

and other exotic forms of electrical materials

but for most introductory physics classes

and problems and tests, you can get pretty far

assuming that it's either an insulating material

electrically or a conducting material electrically.

Before I talk about the differences between these,

of either an insulating material or a conducting material.

Before I talk about the differences, one similarity

is that both insulators and conductors are composed of

are composed of a positively charged nucleus

and a negatively charged swarm of electrons

Another similarity is that for both conductors

and insulators, the positively charge nucleus cannot move.

just from thermal vibrations, maybe a little bit in place,

but it can't travel freely throughout the material

If it was a fluid, I suppose these things can move

These can move around with almost no resistance,

is that these electrons cannot move around freely.

These don't have the right energy levels and bands

in order to make these electrons move around freely.

For insulators, everything is basically stuck,

but it can't jump around freely from atom to atom

For the conductors, the electrons can do this.

Now the electrons aren't just going to do this on their own,

they have to be compelled to start moving

or setting up some sort of electric field or force.

If that did happen, the electrons in a conductor

but in an insulator, the electrons are stuck

"Well, okay, shoot, for electrical materials

"all we really care about are the conductors.

"The insulators we will just use if we don't want

While that is somewhat true, it is not completely true

because if I set this insulator up to a battery

or set up some sort of electric field or force in here

even though the electrons in an insulator

and the the negatives over on the other end

so what you get is overall this side of the atom

and this side of the atom would be more positive.

now because this is set up where the positive

this material, if you get all of them to do this

an overall electrical effect where this insulator

Even though the charges can't flow through an insulator,

Now, let's see what happens if we add extra charge

I mean, the way they started off right here

we had just as many positives in the nucleus

and that's true for the conductors and insulators.

Well, it'll get really messy if we try to draw it

with all the atoms, so since these all cancel out

their overall charge, I am not going to draw

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Conductors and Insulators | Physics | Khan Academy

sort

stick

bunch

pretend