Charge induced on parallel plates if a charge between plates

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Homework Help Overview

The problem involves two infinite conducting plates separated by a distance, with a point charge located between them. Participants are tasked with finding the charges induced on each plate due to the presence of the point charge. The context suggests a focus on electrostatics and the behavior of electric fields in the presence of conductors.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the method of images as a potential solution, noting the complexity of using an infinite sequence of image charges. Some express uncertainty about the assumptions involved in this method. Others mention Green's reciprocation theorem as an alternative approach.

Discussion Status

The discussion is ongoing, with participants sharing their attempts and expressing difficulties in applying the image method. There is acknowledgment of the complexity of the algebra involved. Some participants are seeking clarification on whether the discussed methods yield the induced charge distribution or merely the electric field or potential.

Contextual Notes

Participants note that the problem may be challenging due to the infinite nature of the plates and the point charge's position. There is a sense of urgency among some participants, particularly those with a background in physics, who are looking for a deeper understanding of the problem.

Rakesh Kumar Jaiswal
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Two infinite conducting plates 1 and 2 are separated by a distance l. A point charge q is located between the plates at a distance x from plate 1. Find the charges induced on each plate.

Many of the places this problem has been solved by considering an infinitely large plate in place of the point charge. This solution is also given in the Irodov book itself. I get the answer by this assumption but I don't understand this assumption fully. I have tried a lot to find any alternate method to solve this problem but could not get one. Now I am posting here with a lot of hope that somebody would certainly help me out.

Can anybody solve this question by any alternate method?
 
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Rakesh Kumar Jaiswal said:
Two infinite conducting plates 1 and 2 are separated by a distance l. A point charge q is located between the plates at a distance x from plate 1. Find the charges induced on each plate.

Many of the places this problem has been solved by considering an infinitely large plate in place of the point charge. This solution is also given in the Irodov book itself. I get the answer by this assumption but I don't understand this assumption fully. I have tried a lot to find any alternate method to solve this problem but could not get one. Now I am posting here with a lot of hope that somebody would certainly help me out.

Can anybody solve this question by any alternate method?

One solution would be to use the method of images. But, in this case, you will need an infinite sequence of image charges in both directions.

Using Green's reciprocation theorem is another approach.
 
PeroK said:
One solution would be to use the method of images. But, in this case, you will need an infinite sequence of image charges in both directions.

Using Green's reciprocation theorem is another approach.

Thanks ReroK

I have tried to solve this by image method also but could not get the answer. At the limiting case (boundary conditions) I get equal charges induced on both plates.

Would you please solve this for me?
 
Rakesh Kumar Jaiswal said:
Thanks ReroK

I have tried to solve this by image method also but could not get the answer. At the limiting case (boundary conditions) I get equal charges induced on both plates.

Would you please solve this for me?

I'm afraid, we can't just do your homework.

For what it's worth, I suspect the image method is quite hard. Quite complicated algebraically, at least.
 
PeroK said:
I'm afraid, we can't just do your homework.

For what it's worth, I suspect the image method is quite hard. Quite complicated algebraically, at least.

Many people says this problem can be solved by image method but I could not find one who could actually solve this.

I am a physics faculty and I do my homework. It is long waited question to be solved for me. Please help me if you can.
 
Rakesh Kumar Jaiswal said:
Many people says this problem can be solved by image method but I could not find one who could actually solve this.

I am a physics faculty and I do my homework. It is long waited question to be solved for me. Please help me if you can.

Well, I found at least one solution just by searching:

"method of images two parallel planes"

Although it seems that the method of images leads to an infinite series that cannot be simplified.

I also found a solution based on the Green reciprocation theorem, which looks like the way to go.
 
PeroK said:
Well, I found at least one solution just by searching:

"method of images two parallel planes"

Although it seems that the method of images leads to an infinite series that cannot be simplified.

I also found a solution based on the Green reciprocation theorem, which looks like the way to go.
The question asks for
Rakesh Kumar Jaiswal said:
Find the charges induced on each plate.
I take that as meaning the induced charge distribution. Do those methods answer that or only find the field/potential?
 
haruspex said:
The question asks for

I take that as meaning the induced charge distribution. Do those methods answer that or only find the field/potential?

The Green method finds the charge distribution. I searched for "two infinite grounded conducting planes". It's problem 1.13 from Jackson.

The method of images solution I found was looking for the force on the particle.
 

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