Questions tagged [charge]
A fundamental property of matter which causes it to experience electromagnetic forces.
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Do conductor plates encloising charged particles exert a force on one another due to the charges induced on them? How to calculate in a 1D model
I would very much appreciate some guidance on the below.
Consider a one-dimensional world as depicted in the attached figure.
We have two (lets say positively charged) particles enclosed by two ...
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Surface charge density of a conductor is inversely proportional to radius of curvature: proof? [duplicate]
I have heard the statement
"The surface charge density at a point on a conductor is inversely proportional to the radius of curvature at that point"
For example in this stackexchange post.
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Independence of electric charge on inertial frame [duplicate]
In most of textbooks I am familiar with (with one exception - Matveev’s course) it is tacitly assumed that electric charge is independent of an inertial frame.
I am looking for a reference to a more ...
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Problems with equipotential lines of electric dipole with different charges
First of all, sorry for the mistakes I may have in my post, I am not very good in English.
I just had an exam and a homework where I was asked the following problem and I attach my solution with my ...
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Purpose of potential difference in the presence of an electric field
Based on my understanding, charges are pushed along wires due to an electric field created by the battery, and charges gain electric energy as they loop through the battery. But I can't seem to ...
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Why do spherical M2 branes have no net charge?
In the paper Invasion of the Giant Gravitons from Anti de Sitter Space, the authors claim that
We are interested in the dynamics of a relativistic spherical membrane moving in $S^4$. The
membrane has ...
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What is the mechanism by which objects feel the electrostatic force?
This is more of a conceptual question than a mathematical one, but you may answer however you wish.
Suppose we imagine a universe with a single proton in it, then magically create an electron one ...
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Field of an Uniformly Charged Infinite Plane Sheet
Let's consider two cases:
Let's say that we have two positive point charges. If we get those charges together very very very close to each other, the repulsive force goes to infinity between those ...
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In JJ Thompson's experiment, why are electrons not making U turns?
In JJ Thompson's experiment,
Why are some electrons able to pass through the slit of the anode, rather than hitting the anode plate itself?
Even though electrons manage to get past the anode, will ...
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Accelerated Electric Charges
We know that an accelerated electric charge produces electromagnetic radiation.
We also know that acceleration is relative to an observer.
Take electrically neutral observers A and B, who are ...
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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 ...
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Interpretation of Gauss law for displacement field
I am studying Griffiths' introduction to electrodynamics and I struggle to understand the field of application of $$\int{D \cdot dA}=Q_{f_{enc}}.$$ Griffiths states that this law holds within ...
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Charged particles deflected by gravitational and magnetic fields
I am trying to better understand one of my previous questions, and another.
Charged particle in uniform Magnetic field
Does a charged particle orbiting Earth radiate?
https://en.wikipedia.org/wiki/...
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Neutral Hydrogen Atom Time-Averaged Potential
I'm self-studying the 3rd edition of Jackson's Classical Electrodynamics and I have a question about a problem. The fifth problem of Chapter 1 asks the reader to determine the volume charge ...
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Charge distribution on co-planar capacitors
I'm looking for books on a complete analysis of co-planar capacitors and their electric fields at DC, such as between narrow and wide traces on a PCB. Any suggestions?
I think there's a some research ...
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Potential at a point at a distance from the centre of spherical shell with uniform surface charge density when point charge potential is abnormal?
So we assume that the electric potential of a point charge has the following form:
$$
V(r) = \frac{1}{4 \pi \varepsilon_0} \frac{q}{r^{1+\epsilon}}
$$
rather than the usual Coulomb potential.
Now we ...
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Does a charged particle orbiting Earth radiate?
I found this question, for which the answers I did not understand:
Does a charged particle accelerating in a gravitational field radiate?
So I want to dumb it down.
From my backyard, can I see ...
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Effect of a current-carrying infinite wire moving towards a stationary charge
An infinite wire carrying electrical current moving towards a stationary charge (perpendicular direction), why is there an electrical force on the charge in a direction parallel to the wire? I can ...
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How does something acquire postive charges?
I understand that an object becomes postively charged when it looses electrons.
I was curious, at 5:45 of this video Electronics at Work - 1943 (https://www.youtube.com/watch?v=hwutHPYGgfU), how does ...
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Deriving continuity equation from 4-current of a charged particle
how can i check that following 4-current for a single charged particle
$$j^{\mu}(x)=qc\int d\tau u^{\mu}(\tau)\delta^{4}(x-r(\tau))$$
satisfies continuity equation $$\partial_\mu j^\mu = 0.$$
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Determining vector fields in a Spherical Capacitor with Quadrant Dielectrics
I am working with a spherical capacitor consisting of an inner radius R1 and an outer radius R2. The region between the plates of the capacitor is filled with four dielectric materials, each shaped ...
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Electric current Lorentz transformation
What is the Lorentz transformation of the (scalar) electric current, $I$ ? I got two answers that are not consistent: Consider a lab frame where the charges are moving with a velocity $\vec{\beta}_q$, ...
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Radiation of accelerated Charge: Impact on macroscopic objects
Accelerated charge obeys an energy loss due to radiation. This is one reason why the classical picture of electrons orbiting the nucleus would result in a non-stable atom since the electrons would ...
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Is electric charge dependent on mass of an object? [closed]
I got this question while reading about electrons and protons where electrons having less mass than protons but possess the same amount of electric charge,though negative.
Could you please elaborate ...
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The Komar mass of the second Killing vector in the Schwarzschild metric
In David Tong's lectures on general relativity the interpretation of the $M$ which appears in Schwarschild metric:
$$ds^2=-\left(1-\frac{2GM}{r}\right)dt^2+\left(1-\frac{2GM}{r}\right)^{-1}dr^2+r^2\...
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Why is mass so variable in elementary particles compared to charge, spin, etc [duplicate]
Why is it that the standard model gives very even charge and spin for elementary particles that can easily be compared to each other as integers and simple 1/2, 1/3, fractions whereas some particles ...
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Electric potential and electric field within a hollow sphere [closed]
suppose there is a hollow conducting sphere with a charge inside it, but not in the center of the sphere. then there is a point charge like $q'$ outside this sphere. here is my question: does the $q'$ ...
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Energy conservation of oscillating electric field interacting with charged particles
Consider a charged particle at rest in a vacuum. A traveling oscillating electric field reaches the particle, making it oscillate as well. The particle has gained kinetic energy with that interaction, ...
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Is the electric charge of a bound electron measurable?
What gives us the certainty that the unit charge of a free electron - measured and confirmed with the highest precision in numerous experiments - is retained even when approaching and integrating into ...
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Why does the mechanism producing matter-antimatter asymmetry keep our universe electrically neutral? Any general argument?
I've noticed what seems to be a fine-tuning issue. To be more specific, electric neutrality implies that the amount of lepton asymmetry produced through some unknown processes precisely cancels out ...
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Behaviour of electric field when an electric dipole is placed inside a conducting shell
Suppose there is a spherical shell made of a perfectly conducting material with inner radius $R_{1}$ and outer radius $R_{2}$. A dipole with charges $+q$ and $-q$ separated by a distance $a$ ($a<R_{...
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For steady current, why volume charge density is zero?
The divergenc of steady current density is zero
$\nabla \bullet \vec{J}=0 $
And, by microscopic Ohm's law $ \vec{J}=\sigma \vec{E} $
If the conductivity is uniform, we can get $\nabla \bullet \vec{J}=\...
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Basics of Capacitor
Looking at the formula $C = \frac{Q}{U}$ does a high capacitance mean that with a low voltage we can bring more charge onto the capacitor? How is total charge on the capacitor linked with voltage?
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How can a free electron "oscillate" in the presence of em waves?
I have been told a many times that in a region with oscillating electric and magnetic field, a free electron if left will also oscillate. But I don't think its true. I actually asked this to my ...
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Charge of a particle is running when getting closed to charged black hole horizon
Given some particle with a mass $m$ and charge $q$ in the background of some charged black hole with a mass $M$ and charge $Q$ given for example by the Reissner Nordström metric.
Is it reasonable that ...
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Charge distribution of a proton
I've been studying high-school level physics and I noticed that protons are composed of up-up-down quarks. It is known that fields can be non-uniform due to geometries: Earth's gravity field is not ...
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Constant Voltage In a parallel circuit
We know that in a parallel circuit the voltage in each resistor is the same, but that doesn't make sense at all, I mean lets consider a circuit with a parallel resistance r1 and r2. V = IR is applied ...
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Total charge calculation of a spherically symmetric electric potential in the background of a Schwarzschild like metric
Given a static, spherically symmetric electric potential $\phi(r)$ in a d-dimensional spacetime with a background metric of a d-dimensional Schwarzschild-Tangherlini black hole, i.e.:
$$ds^2=-f(r)dt^2+...
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Time dependence of de Broglie wavelength of an electron with initial velocity $V\hat{\imath}$ and in a uniform magnetic field $B\hat{\jmath}$
I am supposed to comment on the time dependence of de Broglie wavelength of an electron with initial velocity $V\hat{\imath}$ and in a uniform magnetic field $B\hat{\jmath}$.
Obviously since the ...
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Interpretation of Equation of energy stored in continuous charge distribution [duplicate]
In the book "Introduction to Electrodynamics" by David J. Griffiths, $\boldsymbol\S$ 2.4.3$\blacksquare $ The Energy of a Continuous Charge Distribution, I came across this equation for ...
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Given an electric potential in curved spacetime, how to calculate the total electric charge?
In general $d$ dimensional setup ($d-1$ spatial coordinates and $1$ temporal), with a nontrivial metric $g_{\mu\nu}(t,\vec{r})$, having for simplicity a static electric potential $\phi(\vec{r})$.
How ...
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Evolution of a charge density field with a continuity equation
Imagine you have a field, $\rho(\mathbf x, t)$, that represents the density of electric charge in a region of space.
It is well known that
(If $\nabla \cdot \mathbf u = 0$):
$$
\frac{\partial \rho}{\...
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What is the value of $e^2$ in CGS units? [closed]
Seems yo me that units of the square power of electron charge $e^2$ are in the SI units system Coulombs squared, $[C^2]$.
But what are the corresponding units of $e^2$ in CGS units system? I am not ...
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How do protons transfer from one object to another by induction?
Charging by induction begins with a positively charged object and a neutral object which causes the electrons on the neutral object to be closer to the charged object. In diagrams I saw online, when ...
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When is the charge generating isometries given by a symplectic product?
I am reading the following paper https://arxiv.org/abs/2309.15897 and have the following confusion:
The authors look at the covariant phase space of linearised general relativity after one expands ...
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Is there electric field inside the conductor in moving charges case?
Is there an electric field inside a conductor when steady current passes through it ?
I have two conflicting notions here : I was watching this Electroboom video and at minute $14:00$ electroboom ...
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Why is current defined as $dQ/dt$ even though it is not defined as the rate of 'change' of flow of charges?
I do not understand this definition. $dQ/dt$ represents the rate of CHANGE of charge flow at an instant even though current is defined as only the charge flow per unit time.
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Does electric charge have any effect on diamagnetism?
Diamagnetic materials repel magnetic fields because freely moving electrons or cooper pairs within the material can form eddy currents in response to a changing magnetic field.
It is natural to wonder ...
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Charge accumulation at the boundary of two dielectrics in a capacitor
Say we have a capacitor filled with two dielectrics of different constants. The two charged plates of the capacitor are +V and -V. Does charge accumulate at the boundary of the dielectrics? In my ...
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Should we expect lightning-like phenomena as matter enters the accretion disk of a black hole?
As matter enters the accretion disk it will rapidly turn into superheated plasma. I would expect this to coincide with lightning-like phenomena due to the electric potential difference between this ...
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