Explorers of the Deep - 2020-09-03

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7:47 AM

Hey I was reading your question

0

Q: Why do electrons in a conductor not connected to a power source not fly away due to repulsion?

Let's assume that a conducting element is kept on a table (to indicate that no power source is connected across its ends). So, all the electrons move in random directions and repel each other. The question I have is "Why do they not fly away?" I think that they don't have enough energy to escape...

electrostatics electrons charge

You said ,"So, all the electrons move in random directions and repel each other."

I have read somewhere that electrons in a conductor only start moving when an emf is provided.

So how can they move when conductor is not connected to a power source?

Aren't they motionless when an emf is not provided?

8:03 AM

They repel each other and so, they should move haphazardly (it seems random), I think.

8:20 AM

Ok

Let me ask Rennie

Good idea

Let me know too

Hey

I have a doubt

Are you free for 2 minutes?

Yes @Mayank

Go on

8:35 AM

It is from electrostatic.

Okay, what is it?

I have to tell you in advance, I will most probably not be able to answer it

When a positive charged ebonite rod is placed near a neutral metal conductor standing on an insulating rod.

Hmm...

Then the negative charge accumulate near that ebonite road in metal conductor

I think we should think in terms of electrons and protons

rather than positive and negative charges. I am more comfortable with it

8:39 AM

What will we do if we have to remove positive charge from conductor?

Also, it gives me some intuition.

I think I can answer that

Now, let's translate your question in terms of electrons and protons, shall we?

In book it is given that we would ground the other side of conductor by wire?

@RajdeepSindhu wait

@Mayank Okay...

I am not able to edit the message

No problem, just copy it and make the changes and resend it

8:42 AM

How would we remove positive charge from the conductor?

Is that the complete question?

Yes

The summary of your question is "How do we remove positive charge from the conductor?", right?

Okay, we still have to translate to electrons and protons for better understanding

I may sound stupid asking this question

Not at all

these are the questions that give you great insight and intuition

Also, one MUST ask stupid questions. Now, back to the question

We have a positive net charge on the ebonite rod

8:44 AM

@RajdeepSindhu can you do translation because i don't know how to replace positive charge with proton?

@Mayank Yeah, sure

Cause positive charge mean less electrons

Which mean that there are more protons than electrons

Now, the fact that there are more protons than electrons will cause the electrons in the atoms of the conductor on the rod to move towards the ebonite rod

Yes

which means that on the left side, there will be lack of electrons

8:46 AM

Yes

When we ground the left side (the side with a positive charge or less electrons), the electrons will flow from the earth to the left side and so, the left side will become electrically netural

Wait

And the excess of electrons on the right will be equally distributed over the conductor on the rod (if it is a sphere, that is) and the sphere will become negatively charged

I think this should be the answer...

Can electrons travel from earth to an metalic rod?

I believe they can, I read it in a book

I can confirm this and let you know in the evening if you don't need the answer immediately...

Do you?

8:48 AM

Yes

I an not in a haste

Good, anything else?

Hey Rennie sir have answered the question

"That's a complicated question because the electrons in a conductor are in a delocalised state i.e. they are spread out over a large volume of the metal.
To a good approximation they are in momentum eigenstates so any individual electron has a non-zero and actually very large velocity. But on average the electron velocity is zero when no current is flowing."

Nice, what did he say?

I have no idea what momentum eigenstates is

Neither do I, neither do I, lol

Tell him you're in 10th grade

He answered my question with vector calculus, I think

8:50 AM

He know

I have told him

Yesterday

Well, tell him that you don't know what it means

Which room are you in?

Hey

Something is in my mind

Have you read about drift speed?

What is it?

Not properly

I think I am relating that to drift speed

Because in drift speed the velocity of an electron is very hight but it averages out to nearly $10^-6$

Sorry, I don't know much (read as 'anything') about it

10^-6 what (units)?

8:54 AM

I just googled eigenstates movement

@RajdeepSindhu m/s

Let me confirm

@Mayank High level stuff

Nope

It is 10-3 m/s

@RajdeepSindhu it is in class 12 ncert electric current chapter

Oh, still high level, lol

Did you get your answer @Mayank?

Google says eigenstates movement is related to quantum mechanics

Yeah, high level stuff, as I said :/

8:57 AM

@RajdeepSindhu you said you would tell me in the evening

I will, about the question you asked me about charging from induction

Yes

Not about the question that you asked about my question. I'm not so sure about the answer to that

That's why I am doing it from 12th

I fear that only doing class 10th electricity will lead me to make certain assumptions that turn out to be wrong and turn into misconceptions

I have fallen a victim to this many a times

The worst thing is not being able to know what you don't know

I think you get it...

@RajdeepSindhu yes

Hey

So, is that all?

@Mayank yeah?

9:04 AM

Don't you find relative permittivity and refractive index samein a sense both compares things in air to a particular medium?

I don't know what "relative permittivity" is

Is the the permittivity of a medium with respect to permittivity of another medium?

I do find the similar, not same.

Yes I mean the same

By in sense of

Ok

Bye

Bye :)

4 hours later…

1:20 PM

Did you get the answer?

4 hours later…

5:13 PM

@RajdeepSindhu

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