Questions tagged [conductors]

For questions about materials which allow the flow of an electric charge (electrical conductors) or the transfer of heat (thermal conductors) through them.

Filter by
Sorted by
Tagged with
0 votes
1 answer
32 views

Field outside a hollow conductor

Feynman shows in his Lectures on physics, Volume 2, Section 5.10 that in a hollow conductor there can be no electric fields inside the cavity. But he also says that no static charge distribution Q ...
Leif Dietz's user avatar
0 votes
1 answer
19 views

Equilibrium constellations of classical point charges in hollow conductors

As far as I know, in free space there can be constellations of $N$ point charges in electrostatic equilibrium (albeit unstable equilibrium) for all $N$ except $N=2$. Some discussions here already ...
Jos Bergervoet's user avatar
1 vote
0 answers
106 views

Why Can The Charge Distribution of A 2D Conductor Be Determined By Flattening Its 3D Counterpart?

The most famous instance of this trick is probably in the case of finding the surface charge distribution of a charged conducting disc, where this disc can be perceived as a squashed down version of a ...
davidaddisonsenjaya's user avatar
0 votes
1 answer
64 views

Could you calculate the force between two NON-PARALLEL, straight current carrying wires?

Just like there are ways to solve for the force between two straight parallel wires, what is the way we could find the force between non-parallel wires?
linoloml's user avatar
0 votes
1 answer
60 views

How does charge move in conducter which is between two connected conductors [closed]

Two square conductors with neutral charge and surface $A$ and $d<<\sqrt{A}$. The conductor in the middle is the same shape but with a very small hight, $dh$, and is charged with $q$ How to ...
amit's user avatar
  • 11
1 vote
3 answers
43 views

Charge Inside a conducting hollow sphere

Let two concentric hollow charged conducting spheres of radius R1 and R2. If charge on inner sphere is Q1 and for outer it is Q2, wouldn't the resulting electric field due to the whole system be '0' ...
Amit Rai's user avatar
  • 143
1 vote
1 answer
47 views

What is the electric field inside a perfect conductor connected to a DC source?

We all know from a course on electrostatics that the electric field inside a perfect conductor, placed inside a static electric field, is zero. Now imagine the same perfect conductor is connected to a ...
Solidification's user avatar
1 vote
1 answer
53 views

Why force by electric field is appearing?

I want to ask about the Hall effect. Why is the force by the electric field appearing? I can understand the appearance of the Lorentz force. However, I do not know for what reason the force due to the ...
diana's user avatar
  • 11
0 votes
0 answers
13 views

What is meant by a source-free conductor?

I have recently worked with a source-free conducting slab filled with free space and with an electric field inside, and I have determined the corresponding magnetic field from MW's eq's. Next, I ...
Rasmus Andersen's user avatar
2 votes
5 answers
200 views

Electric displacement field in a conductor

The photo given below is from the solution manual to Griffiths Electrodynamics, it claims that the displacement field inside a conductor a zero. Now I do not see why it is obvious , $ D = εE + P $, ...
L lawliet's user avatar
  • 297
0 votes
0 answers
17 views

How would surface dipoles change the internal potential in a conducting sphere?

In the nanoscience literature, there is a model of semiconductor nanoparticle doping which ascribes the effect to surface dipoles shifting the absolute state energies relative to the environmental ...
intraband's user avatar
0 votes
0 answers
37 views

Expectation Value of the BCS Hamiltonian

I want to calculate the expectation value of the BCS Hamiltonian $ H = \sum_k E(k) c_k^\dagger c_k - \frac{V}{2} \sum_{k,q} c_{k+q}^\dagger c_{-k-q}^\dagger c_{-k} c_k $ in the state $| \Psi \rangle = ...
ConanFromChester's user avatar
2 votes
2 answers
73 views

Would seawater flow be affected by a magnet?

Let's suppose that there are two streams of sea water, flowing on a flat inclined surface. Both of the streams are distant, independent of each other and parallel to each other. Now lets image I put a ...
Dario Deniz Ergün's user avatar
3 votes
3 answers
566 views

Understanding Kirchhoff's first law in charged conductors

I wonder about Kirchhoff's first law in charged conductors. Consider: $$j = \sigma E \implies \nabla \cdot j = \sigma (\nabla \cdot E) = \frac{\sigma \rho}{\epsilon_0}$$ This means that Kirchhoff's ...
Niclas's user avatar
  • 191
0 votes
3 answers
101 views

If $\vec{E}=0$ inside a conductor, then there's no charge distribution?

I got this answer to my last post, See answer. That raises another question, then. Knowing $\nabla\cdot\vec{E}=\frac{\rho}{\epsilon _0}$, then $\rho$ should be $0$ (because $\vec{E}=0$). But it's not, ...
Ruba18's user avatar
  • 152
6 votes
1 answer
346 views

Will charges rearrange inside a conductor, or not?

I'm confused about how conductors work. So, imagine we have a spherical conductor, charged with a certain potential, $V$, that must remain constant. Now, this sphere has a cavity inside, where we put ...
Ruba18's user avatar
  • 152
0 votes
1 answer
63 views

Why is potential difference across resistor different than potential difference across a wire?

As far as I understand, the electric potential is the amount of energy that a third party agent has to spend to move a positive charge from infinite separation to a point. Thus, the electric potential ...
Роман Кирьянов's user avatar
3 votes
3 answers
419 views

Confusion about Circuits

I have two questions: When dealing with simple DC circuits, it is often said that the electrons in the wire move because the charge density of the surface charges decreases. Is that due to the fact ...
Blue2001's user avatar
  • 268
0 votes
1 answer
46 views

Electric field in the hole of a conductor

My textbook has the following question: A hollow charged conductor has a tiny hole cut into its surface. Show that the electric field in the hole is $ \sigma/2\epsilon_0$ $\hat{\mathbf{n}}$, where $\...
archthegreat's user avatar
1 vote
2 answers
98 views

What is resistivity? [closed]

What is actually resistivity? I read that when the temperature increases the the resistance of the conductor increase. Length and area of a material doesn't change so it means that the resistivity of ...
Alex's user avatar
  • 1,431
1 vote
0 answers
44 views

Electromagnetic fields in voltage biased conducting strip

Consider a conducting rectangular strip of length $L$ (along x-axis) and width $W$ (along y-axis), with a potential difference (rather EMF $\int E.dx$) V(t) applied. We can assume that V(t) changes ...
evening silver fox's user avatar
0 votes
2 answers
50 views

How does a conductor in electrostatic equilibrium have no interior electric field?

Can't you construct a Gaussian surface small enough to surround only one of the interior protons, thus the surface has a charge enclosed and a electric field by Gauss's law.
Atticus Deutsch's user avatar
1 vote
1 answer
74 views

Why does current not decrease in/after a resistor if electrons are impeded/lose energy? [duplicate]

I was told that current is uniform across a series circuit. Yet I was also told that a resistor works by impeding the flow of free electrons, which should mean slowing them down. Does this mean that ...
rde's user avatar
  • 11
2 votes
0 answers
43 views

What is the most electrically conductive material at standard temperature and pressure?

Searching the internet, I find plenty of sources telling you the most conductive element is silver, and plenty of articles about potential room temperature superconducting alloys (none of which have ...
Mark Raymond's user avatar
0 votes
2 answers
130 views

Why are lithium and beryllium such good conductors but not chlorine?

Why are lithium and beryllium so conductive? The $2s$ band has a much different energy range from the $2p$ band, so I guess the only explanation is that $N$ states are empty. But if that was the case, ...
Root Groves's user avatar
0 votes
1 answer
48 views

Pn junction and the structure of diodes

I've read the part about pn-junction from Manfred Albach's "Elektrotechnik" book and I've seen some resources online as well. However, there are a few questions that bother me and prevent me ...
Electricity's user avatar
0 votes
1 answer
35 views

How to calculate impedance in a wire moving through a magnetic field?

I'm trying to build a homemade rail accelerator. I understand that the force on a wire is proportional to the cross product of the magnetic field vector and the current vector. I asked my professor ...
Joseph Summerhays's user avatar
2 votes
2 answers
82 views

How are neutral conductors neutral even though they microscopically aren't?

When dealing with electromagnetic waves inside conductors we take $$\nabla \cdot E = 0$$ and I believe we use the fact that conductors are neutral to do this. However, even though conductors on ...
eli morhayim's user avatar
2 votes
1 answer
149 views

Why is the potential due to induced charges constant?

Over the past few days, I have taken the time to read this interesting paper, where an unexpected counterexample is given that shows how the electrostatic force between a neutral metal conductor and a ...
Bml's user avatar
  • 399
1 vote
1 answer
55 views

Is Faraday's cage described in electrostatic 100% insulated?

I apologies if my wording is bad or it is duplicate. I'm new to Electrostatics. During the topic of conductors & electric field I was introduced to Electrostatic Equilibrium state in which the ...
Prabhas Kumar's user avatar
1 vote
0 answers
27 views

Do electrons build up at the entrance of a resistor? [duplicate]

There is a voltage drop between the start and end point of a resistor. How does it achieve this difference in potential? For there to be a difference in potential there must be difference in charges. ...
WilliamHarvey's user avatar
0 votes
1 answer
26 views

Can the formula for a conductor be applied to a grounded infinite conductor plate?

I'm studying about Image method with "Introduction to electrodynamics-Grffiths" And, this book explains the process finding the induced surface charge density when a point charge $q$ is held ...
KHJ's user avatar
  • 105
0 votes
0 answers
25 views

Electric field inside wire [duplicate]

So I m a high school student and I learned that electric field inside conductor is 0 when it is placed in external electric field due to induced Electric field inside. How can electrons flow if E(net)=...
AIŚVARYA SINGH's user avatar
1 vote
4 answers
77 views

In a conductor responding to an external $E$-field do the electron clouds just shift slightly or do the electrons fully dissociate to go to one side?

For a conductor in an external field, I would like to know whether the electron clouds of each atom, just shift slightly (resulting in positive charges just on one edge, and negative charges just on ...
PhysMs's user avatar
  • 160
0 votes
1 answer
50 views

When electrons go to the outside surface of a conductor why doesn't that create an electric field pointing radially outwards? $E$ is supposed to be 0

If an isolated conductor has a net zero charge and is not in an external field, would the free charges still move to the surface of the conductor eg. a conducting sphere? Wouldn't this create an ...
PhysMs's user avatar
  • 160
0 votes
1 answer
33 views

Electric potential generated by the accumulated charge on a grounded spherical conductor near a point charge

Suppose that a positive point charge is placed near a grounded spherical conductor. According to my understanding: the point charge would generate a positive, generally non-uniform electric potential ...
Maury's user avatar
  • 13
1 vote
2 answers
33 views

Static condition of surface charges

We know that when charge is supplied to a conductor,they rearrange themselves on the surface thus making a static equilibrium condition. Let's suppose we have $+2e$ charge on a plane sheet conductor. ...
a_i_r's user avatar
  • 341
0 votes
2 answers
75 views

How did we figure out what resistance was?

We were able to figure out that every material offered some resistance. And we were also able to figure out that there is a constant between current and voltage at a specific temperate. But how did we ...
Mathematition_From_Wallmart's user avatar
0 votes
0 answers
81 views

What is quantum mechanical explanation of resistance?

I would be very happy if I get any help with any of this questions. And I am sorry if I make any grammatical mistakes, I don't know grammar well. I guess, the problem for understanding how resistance ...
malikbeyy's user avatar
3 votes
1 answer
129 views

Contractions in current-current correlator for Kubo formula

To calculate the conductance $\sigma_{ij}(\mathbf{q}, \omega)$ of e.g. a disordered electron gas using the Kubo formula, one must compute the (imaginary-time-ordered) current-current correlation ...
xzd209's user avatar
  • 2,147
0 votes
1 answer
33 views

What happens if you connect a surface to ground?

Let's say we have the concentric spherical conductor surfaces, and we connect them to $V_1,V_2,V_3$ respectively, and say we wanted to disconnect the middle one and connect it to the ground such that $...
Ulshy's user avatar
  • 69
1 vote
3 answers
128 views

Is current directly proportional to electron density?

If current $i$ is directly proportional to free charge density $n$, then this means that a greater charge density will lead to a greater current. But simultaneously, this will also lead to more ...
Sukriti Sharma's user avatar
0 votes
1 answer
57 views

Unique distribution of charge on a conductor

If i place some charge on a conductor then it will distribute itself in such a way that electric field everywhere inside is zero. My text book says that only one kind of such charge distribution is ...
Mr. Wayne's user avatar
  • 343
3 votes
3 answers
288 views

Motional EMF and Faraday's law in this case

My textbook states that when a straight conductor with a velocity perpendicular to itself and the magnetic field (see image), an emf will be induced between the two ends of a conductor. This means ...
Xyz Zyx's user avatar
  • 31
2 votes
0 answers
52 views

Distribution of charge in uniform hollow sphere

In electrostatics we learn that if we put excess charge in a hollow sphere, the charges eventually get distributed on the surface uniformly. But there is one thing I don't understand: hollow sphere ...
a_i_r's user avatar
  • 341
1 vote
0 answers
44 views

What happens in a conductor when the electric field has a plasma frequency?

The complex index of refraction for a conductor is given by the equation: $$N(\omega)=n+ik=\sqrt{1- \frac{\omega_p^2}{\omega^2+i\gamma\omega}} $$ where $\omega_p^2=Nq_e/\epsilon_0m_e$ is the plasma ...
davise's user avatar
  • 11
1 vote
2 answers
72 views

Non-resonant source in a conducting cavity, what happens?

First of all I'm aware of this post but my question is a little different. Say we have a perfectly conducting cavity with supported frequencies $\omega_n$ and a harmonically varying source within ...
AfterShave's user avatar
  • 1,780
0 votes
1 answer
157 views

Does the physical shape of a current carrying conductor affect the shape of its magnetic field?

I am wondering if the physical shape of a current carrying conductor will have any effect on the shape of its magnetic field or is it that the magnetic field surrounding any current carrying conductor ...
user57467's user avatar
  • 403
5 votes
1 answer
786 views

Doubt regarding an assumption made in an example in Griffiths

In Griffiths' Introduction to Electrodynamics, example 14 in chapter 7, "Electrodynamics." He makes an assumption/claim that I don't understand the reason behind, or don't agree with. ...
nickbros123's user avatar
0 votes
1 answer
55 views

Conducting liquid between the parallel plates in a capacitor

Let's consider an electrical circuit consisting of a battery, some resistance and a parallel plate capacitor. If the space between the two plates of the capacitor is replaced by a conducting fluid (...
CrookedWarden13's user avatar

1
2 3 4 5
27