charge on a mettalic plate

how do i create charge on a metallic plate?
like say copper plate and i want to create charge on it then,how can i do this?

Lets change the question - can you prove it hasn't already got a charge on it?

(Think carefully about the answer - it will give you a clue about how charge is measured)

Brian.

betwixt said:

Lets change the question - can you prove it hasn't already got a charge on it?
Brian.

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no i actually cannot because if i bring a charged plate towards it then it will induce equal and opposite charge on the metallic plate which proves that it has charge.

now let me ask u another question:
suppose if i take the metallic plate which has got charges induced in it(i mean the latter plate) and bring that plate towards another metallic plate(3rd one) will it induce charges on the third plate?
no right?
because the charges which were induced by the first plate on the second plate were based on just mere attraction of the holes/electrons and not by adding any extra charges so,as soon as we remove the first plate the electrons get back to the respective places neutralizing the effect and so effectively there will not be any charge.
That is why asked this question that how to create charge permanently on a metallic plate?(but i didn't mention the word permanently)

It's one of those topics that starts off sounding simple and finishes with arguments about quantum theory :grin:

As I see it, and I'm not an expert in quantum mechanics, the charge can only exist between two points. You have to assume one is your zero reference and the other is the place you are measuring. Of course, you could equally assume the place you are measuring is the zero and other end holds the charge, you would get the same measurement although the voltage may have reversed polarity.

To answer your new question, I disagree! Your assumption that the charge between plate 1 and 2 is created and destroyed again as they move apart is reasonable, (as long as there is no conduction between them) but as plate 2 gets close to plate 3 the process is repeated and a new charge is built up. The original charge may be gone but the new one replaces it.

I think we have to throw this open to experts for debate...

Brian.

Disha Karnataki said:

That is why asked this question that how to create charge permanently on a metallic plate?

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It sounds as you are asking for a way to insert at the metallic plate a negative charge (= free electrons), which is also referred as Static electricity.

Once these electrons have charge with the same polarity, the resulting physical effect is the mutual repulsion, forcing them to accumulate on the external surface of the metallic plate.

Concerning to the original question, as far I can see, would suffice just open circuit of negative plate from reference while plate is negativelly charged.

Here's what you can do....

1. Charge an insulator such as plastic or glass. This can easily be accomplished by rubbing against silk cloth.
2. Bring the metal plate in proximity to the insulator plate (already charged). Take care not to establish a physical contact between the two.
3. Due to induction, the side (say side A) of the metal plate close to the plastic plate will acquire an opposite charge. The other side (Side B) would acquire the same charge as that on the plastic plate.

Now most important...

4. The charge on side A is BOUND CHARGE. Its not free to move. However the charge on side B is free charge. It can move.
5. Make a ground connection to side B. The charge will move to the ground, and side B will neutralize to zero potential.
6. Move the copper plate away from the plastic plate. The bound charges are no more bound now (due to the absence of binding electric field that was created by the virtue of the charge on plastic plate)
7. The charge that was bound will distribute evenly on the copper plate. Leaving the plate with a net charge, opposite to that on the plastic plate.

betwixt said:

It's one of those topics that starts off sounding simple and finishes with arguments about quantum theory :grin:
To answer your new question, I disagree! Your assumption that the charge between plate 1 and 2 is created and destroyed again as they move apart is reasonable, (as long as there is no conduction between them) but as plate 2 gets close to plate 3 the process is repeated and a new charge is built up. The original charge may be gone but the new one replaces it.
Brian.

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yes charges on the plate 2 get destroyed not on 1.
and i have a point if u disagree that is:
let us take two copper plates and place them facing each other assuming they have gone through the same process as before mentioned then, will they behave as parallel plate capacitor?
then in a similar way we could connect many to get a battery out of it right?
but this all is not my topic to discuss i want to know method to charge a plate permanently.

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mrinalmani said:

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yes this is the exact answer ...
thank you
i will try this.

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