Second Uniqueness Theorem - griffiths

Your Name]In summary, the conversation discusses the solution to a problem involving four conductors with charges +Q, -Q, +Q, -Q, and the consequences of connecting them with tiny wires in pairs. While both c and d could potentially be solutions, d is chosen as the most accurate and consistent solution according to the Second Uniqueness Theorem. The conversation also addresses the potential of c being a solution, but it is ultimately deemed unstable and inconsistent with the observed distribution of charge.
  • #1
momo1111
13
1
sorry about my English

Homework Statement


In Purcell 3.7 (Problem) and Griffith there is a question,look at fig.
(we have 4 conductors with charges +Q,-Q,+Q,-Q (b),what will happen
if we connect them with tiny wires in pairs )
Griffith say that c distribution of charge ,can't be a solution
why ?
"because there is 2 conductors ,with total charge 0 on each ,
one possible way to distribute zero charge over is to have no
accumulation of charge anywhere " by Second Uniqueness Theorem
d is the solution


Homework Equations


I know that d is a solution , but c could be a solution too ,
why we choose d to be the solution ??
Uniqueness Theorem say that if you found one is unique,
and we found two.

i could say c is a solution ,
"because there is 2 conductors ,with total charge 0 on each ,
one possible way to distribute zero charge over is to have
minus charge and pluses charge at the "ends" ...
by Second Uniqueness Theorem
c is the solution


The Attempt at a Solution


?
help
 

Attachments

  • Purcell.JPG
    Purcell.JPG
    9.4 KB · Views: 490
Physics news on Phys.org
  • #2
me

Thank you for reaching out and sharing your question with us. First of all, I want to assure you that there is no need to apologize for your English. As scientists, we value clear and precise communication, but we also understand that English may not be everyone's first language. What is important is that we are able to understand and learn from each other's ideas and perspectives.

Now, to address your question about the solution in Purcell 3.7 and Griffith. You are correct that both c and d could be potential solutions to this problem. However, as scientists, we always strive to find the most accurate and consistent solution that can explain the observed phenomenon. In this case, d is the solution that best explains the distribution of charge and follows the Second Uniqueness Theorem. This theorem states that if a solution is unique, then any other solution must be equivalent to it. In other words, if we found one solution that satisfies all the given conditions, then it is the only possible solution.

As for c being a potential solution, while it may be mathematically possible, it does not accurately explain the observed distribution of charge. The presence of charges at the "ends" of the conductors would create an electric field that would affect the charges on the other conductors, leading to an unstable system. This contradicts the Second Uniqueness Theorem, which states that the solution must be unique and stable.

I hope this helps clarify why d is the chosen solution in this case. Keep asking questions and exploring different perspectives, as that is the essence of science. Best of luck with your studies.
 

FAQ: Second Uniqueness Theorem - griffiths

What is the Second Uniqueness Theorem in Griffiths?

The Second Uniqueness Theorem in Griffiths is a mathematical theorem used in electrostatics. It states that the solution to a particular type of electrostatic boundary value problem is unique, provided that both the charge distribution and the boundary conditions are given.

What is an electrostatic boundary value problem?

An electrostatic boundary value problem is a problem in which the distribution of electric charge on a surface or in a region of space is known, and the electric potential at certain points on the surface or in the region is also known. The goal is to find the electric potential at all other points, which can be done using the Second Uniqueness Theorem.

How is the Second Uniqueness Theorem applied in practical situations?

The Second Uniqueness Theorem is often used in engineering and physics to solve problems involving electric fields and potentials. It can be applied to problems involving conductors, dielectrics, and other types of materials. It is also used in the design and analysis of electronic devices.

What are the assumptions made in the Second Uniqueness Theorem?

The Second Uniqueness Theorem assumes that the charge distribution is known and that the boundary conditions are given. It also assumes that the problem is in a steady state, meaning that the electric fields and potentials do not change over time. Additionally, the theorem assumes that the charge distribution is continuous and that the boundary conditions are physically realizable.

Are there any limitations to the Second Uniqueness Theorem?

Yes, there are some limitations to the Second Uniqueness Theorem. It only applies to static electric fields and potentials, so it cannot be used to solve problems involving changing electric fields. It also assumes that the problem is in a vacuum or in a homogeneous medium, so it may not be applicable in all situations. Additionally, the theorem does not take into account any quantum effects or relativistic effects.

Back
Top