# Questions tagged [charge]

A fundamental property of matter which causes it to experience electromagnetic forces.

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### Infinite electrostatic plate acceleration

So, let's assume you have an infinite charged plate of some charge density, and a like-charged test charge positioned near it. In this case, the test charge is accelerated away from the plate at a ...
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### Let's say I add +2 and +4 micro coulombs of charge on a 1micro farad parallel plate capacitor. How would the charges be distributed?

I have been learning capacitors and I came across this problem where we are adding some charges to a parallel plate capacitor as mentioned above. I have no idea on how charges would be distributed ...
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### How to determine the charge of a $W$ boson in a Feynman diagram?

As the title says, I am not sure in what situations there is a W$^+$ boson and when there is a W$^-$ boson. My lecturer explained to me that you can view it either as the $W$ boson supplying a charge ...
1 vote
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### 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 ...
1 vote
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### In Peskin & Schroeder's QFT book page 704, the definition of electric charge is opposite?

In Peskin's book Chapter 4, the QED Lagrangian in Eq.(4.3) which contains the interaction term $$\mathcal{L}_{\mathrm{int}}=-q\bar{\psi}\gamma^\mu\psi A_{\mu}\tag{4.3}.$$ From this Lagrangian we can ...
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### How, in induction of electric charges, the field developed due to separation of charges exactly cancels out the external field?

I have been learning electrostatics, and I didn't quite understand why charges reside only on the surface. The charges are moved until they reach the surface after which they cannot move further and ...
1 vote
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### On which atomic factors of the materials does the phenomena of static charge depends?

Please correct me if I am wrong. Almost all materials are made up of atoms with electrons. If we rub two different materials, like plastic scale and oily hair on the head, then static charge develops ...
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### How charge interact with mass? [closed]

If mass does not interact with charge, why does the mass of an electron move (means by which mechanism it moves) in an electromagnetic field? It is same like we stick ball on magnet with fevistic and ...
1 vote
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### Increasing order of charge/mass ratio for electron, proton, alpha-particle and neutron [closed]

So there is this question where we have to arrange the charge by mass ratio of the aforementioned particles/ions. So I googled for the answer and in most of the places the answer is given as: n < α ...
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### Electrical charges and energy

Since we have defined energy as the ability to do work, how come electric charges (-) and (+) be able to do work without using any energy? If lets say I have a big fixed positive charge and if lets ...
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### Why doesn't the frequency of a cyclotron make an impact on the radius of the path of a charged particle?

The cyclotron frequency is given by $$f=\frac{qB}{2πm}$$ Obviously this equation has nothing to do with the radius. But my question is, when the frequency increases, shouldn't the velocity increase, ...
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### Variance of Capacitance

I'm studying Capacitance as a high school student and I have come across few things which I am puzzled about. I understand that bringing a negatively charged conductor near a positively charged one ...
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### What happens to the potential difference and charge of a capacitor with dielectric if a battery is disconnected?

if I have a capacitor connected to a battery of 12V and it has 3C of charge and I add a dielectric let's say $q$ would increase to 6C and $ΔV$ would remain constant. Now I'll disconnect the battery, ...
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### Decreasing of a charge amount and its effects on a capacitor

There is an equation of charge amount on a capacitor you may know; This graph above shows the charge amount. And according to the book "Fundamentals of Electric Circuit from CK Alexander", ...
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### Quantization of charge from the path integral

Consider a complex scalar field, with the usual Lagrangian: $$\mathcal{L} = | \partial_{\mu} \phi|^2 - V(|\phi|^2).$$ This theory has a $U(1)$ symmetry, $\phi \to e^{i \alpha} \phi$, and the ...
1 vote
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### Why don’t charge carriers constantly accelerate in an electric circuit?

With my current knowledge of electric circuits and electrostatic fields, I would expect that the electric field generated by the potential difference of, say, a cell should exert a constant force upon ...
43 views

### What sort of QED-like theories can have non-quantized charge?

It is often said that the existence of a single monopole would force electric charge to be quantized, due to Dirac's argument. However, one can write down theories like QED that, independently of the ...
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### Is the superconducting wire in a equilibrium DC circuit free of surface charge?

Suppose we have a closed circuit composed of a time constant voltage battery, a resistor and superconducting wires connecting them in series. In the equilibrium state, both the free charge the ...
1 vote
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### How is Law of Conservation of Charge valid if protons and electrons are destroyed in a system?

So I am preparing for an exam with material from openstax books on physics. There in the static electricity chapter I saw this paragraph, "Because the fundamental positive and negative units of ...
1 vote
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### How to know which formula to use for the electric field of a conducting plate of charge? $𝐸=σ/2ε_0$ or $𝐸=σ/ε_0$? [duplicate]

I'm so confused right now as I have come across questions regarding the E.F of a conducting plate of charge.However some questions use 𝐸=σ/2ε0 whereas others use 𝐸=σ/ε0 and I genuinely don't know ...
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### Does a d'Arsonval coil / Oudin coil / "violet ray" electrotherapy device produce a complete circuit?

A few different historical designs exist for "medical" devices that generate a high-frequency oscillating voltage at the open end of a resonator circuit. Solid-state versions are sold on ...
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Is there any way one can modify a known functional so as to get a solution for another quantity related to it? Because this is too general I would like to make it more clear with an example. Given the ...
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### Why my DC thick charging cable is slower than a thinner one? (having same power rating & adaptor)

Does that means thick wire cause more current loss than thinner one?
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### Non-standard circuit

I partially solved this problem. Problem: A charged sphere of radius $a$ is connected through a resistance $R$ to the earth. An electronic flow breaks out towards the sphere of infinity at speed $v$ ...
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### Electrostatic: do Electrons really go away?

So imagine the classic science experiment where you take an empty aluminium can and a rubber bar that you charge with fur. At first, that can is electrically neutral. Two different cases now that I ...
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### Why small particles are attracted by charged objects?

Everyone knows this experiment: You mix salt and pepper and use a charged balloon to separate the pepper from the salt. I never really understood how this works. In school (long time ago) we learned ...
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### How much voltage would be required for a charge to have 1 amp of current with 0 resistance?

Voltage is the energy a charge has. If a charge has some energy it will move forwards. Resistance opposes the charge and it moves slower. But what if resistance was exactly 0. 1--->How much voltage ...
1 vote
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### Is Coulomb written/found on any object/product as its unit?

Today I had physics class and the unit Coulomb made me wonder as to why it was even invented when I don't see it being used anywhere. When I asked where it may be shown just like bulbs have x Watts ...
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### What is the most highly charged celestial body in the universe?

Generally speaking, the universe is electrically neutral and the universe abhors an unbalanced charge. Wherever there is a positively charged object, you can bet there is a negatively charged object ...