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

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Is battery the supplier of charge in an electric circuit?

In a simple electric circuit consisting of wires, battery and a bulb... Are the charges which flow in the circuit provided by the battery or are they coming from somewhere else?
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53 views

Potential of a sphere induced by a charged sphere

I am trying to solve what seems like a simple problem but something is bothering me: Imagine we have a sphere (1) with a charge $Q_1$ and at a distance $d$ we have another sphere (2) which is a ...
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73 views

Does elementary particle emit photon?

Charged particles are accelerated by the magnetic field in a particle collider before allowed to smash together at specific location where the detectors are housed. My question is do the ...
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40 views

Removing the charge from charged object

let's say I have an object with an electric charge Q. I'm not sure if I can remove charge 2Q from it so it will become negative (-Q) or I can't do it. To be specific I have this example: There are two ...
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1answer
54 views

What's difference between C parity and charge?

I know C parity as an operator : $$ C\psi=\pm\psi $$ has two eigenvalues like parity operator P. But what I wonder is, i.e, is it true to say for a negative charged particle has (-) eigenvalue? If not ...
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45 views

Does lightning have a thickness?

We have calculated (probably measured) the speed, temperature and voltage of lightning so does lightning have a thickness? Note: When a lightning occur it heats up the air rapidly causing the air to ...
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4answers
77 views

Why is charge of the electron negative?

How did scientists figure out that the charge of the electron was indeed negative? I know how the cathode ray tube experiment works, but how did Thompson know that the plate that the cathode ray beam ...
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2answers
204 views

Considering this hypothesis…is charge really quantized? [closed]

[If anything goes against any mathematical or physical rules please let me know. I am a first year undergraduate student perusing a joint major in mathematics and physics so I do not have a complete ...
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2answers
85 views

Force when distance between charge is zero

According to coulomb law $$ F = \frac{q_1q_2}{r^2} $$ I want to know what happens to force when $r=0$. If $F \to \infty$ then the charges can't be separated! But if an unlike charge of higher ...
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96 views

Direction of electric field lines and electrostatic force

Direction of electric field and electrostatic force should be same by the equation $$\vec{F} = \frac{k q q_0}{r^2}$$ Electric Field $$\vec{E} = \frac{k q}{r^2}$$ Let us suppose that there is a ...
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68 views

Charge of a moving particle [duplicate]

Is there an experiment that measures the electric charge of a moving particle, therefore proving "experimentally" that it is indeed the same as a static particle?
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113 views

Checking for equilibrium in a square configuration of charges [closed]

Four equal positive charges each of magnitude q are placed at the respective vertices of a square of side length l. A point Q is placed at the centre of the square. Then find the state of equilibrium ...
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2answers
77 views

What actually is a continuous charge distribution? [closed]

I am well aware of the maths of how to do all sorts of calculations using continuous charge distributions (like volume, space, and, line charge distributions) but when I think about it I couldn't get ...
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1answer
36 views

Calculating charge density

When calculating uniform charge density, I yielded a solution with units: $$VC^2 / Nm^2$$ The answer is telling me that this is equivalent to: $$C/m^2$$ where: $$m : meter$$ $$C : Coulomb$$ $$V : ...
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1answer
38 views

Charge loop corrections

Let's assume some theory in which there is some gauge group (spontaneously broken) field $B$ and fermion field $b$ which isn't charged under this group, and this statement must hold for each order of ...
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0answers
24 views

What are non-local charges?

In integrable systems, for example in the XXX spin chain, one encounters non-local charges (that form a Yangian). They are fine since the Yangian generate an infinite number of them, which gives us ...
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1answer
53 views

Potential Difference between 2 points in a curcuit

3 Cells and 3 capacitors are connected as shown in the diagram. What is the potential difference between points A and B ? What are the final charges on each of the plates of the Capacitor ? Does the ...
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31 views

Dirac quantization condition for magnetic monopoles how is obtained? [duplicate]

assuming we have a magnetic monopole charge on the origin with magnetic field given by $$ D= \frac{q.dr}{r^{2}} $$ how is the quantization of the charge for a monopole obtained in this case ?? i ...
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1answer
51 views

Electrostatics and tv screens

My physics textbook states an activity- "Cut out thin strips of paper and lightly iron them. Take them near a TV screen or computer monitor. The strips get attracted to the screen and may cling to the ...
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1answer
53 views

Why can we ignore self energy?

I have been doing some practice questions in a text book [Electricity and Magnetism by Purcell and Morin]. So I know that the energy the potential energy of a system is the total work required to ...
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1answer
48 views

Final charges on Capacitors connected in a curcuit

Capacitor C1 is charged to a Potential Difference of 10V. It's capacitance is 2 microFarad. Capacitor C2 is charged to a Potential Difference of 15V. It's capacitance is 4 microFarad. Now the ...
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3answers
121 views

What does grounding a plate mean happens to the charge?

In the context of image charges. Let say I have a very large grounded/earthed plate. If initially the total charge on the plate is 0 then we place a positive point charge, $Q$ just above its surface ...
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28 views

Weizsäcker–Williams approximation

I'm having some trouble understanding the Weizsäcker-Williams approximation What I think it is is the following: I have a charged particle at high speed, close to the speed of light, at this speed ...
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1answer
53 views

Can we create a electric field without actually using a battery or power source?

Can we create an electric field without actually using a battery or a source of electricity? Like a take 2 panels, one is positively charged and another is negatively charged and put them parallel to ...
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2answers
57 views

Continuity of Potential of an electric field

Consider a point charge $q$ at $(0,0,0)$, the potential at $\bf{r}$ is given by $V(\bf{r})$ $= \frac{q}{4\pi\epsilon_0r}$. If you consider a path through $(0,0,0)$, you encounter a discontinuity in ...
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1answer
48 views

Image charges and capacitors?

Consider these two situations: A (infinite) parallel plate capacitor in which one plate is held at a potential $V$ and the other is grounded. A point charge near an infinite plane and grounded ...
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59 views

Definition of charges

We say that a body is negatively charged when it has excess electrons otherwise say positively or uncharged. We also say that electrons are negatively charged. By the above statement, it has more ...
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1answer
76 views

Energy Loss during Sharing of Charge between two Capacitors

It is fairly easy to show that there is always a loss energy when two capacitors share their charge to attain the same common potential, but is it with the same ease that one can explain why it ...
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22 views

Klein-Gordon quantum relativistic equation negative energy [duplicate]

Interpretation of solutions with negative energies was such that charge, rather then probability, density was assumed. When inserting charge of a particle negative sign is then obviously due to ...
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2answers
56 views

Why do the free electrons in N-type want to diffuse?

I'm trying to understand how a diode works and for this I've used(among other resources) the book written by Albert Malvino, Electronic Principles. Everywhere I read about this topic, it says that ...
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2answers
70 views

Why are the charge operator $Q$ and the baryon number operator $B$ unbounded?

A friend recommended me to read PCT, Spin and Statistics, and All That written by R. F. Streater and A. S. Wightman. In page 5 to 6, here's what the authors of this book have to say: [...] In ...
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1answer
75 views

Is it possible to give photons an electric charge?

I know that photons have no electric charge and that they are stable, but is it possible to give them a positive or negative charge? If so how?
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1answer
187 views

Total Energy Stored in Seven Capacitors [closed]

The capacitive network shown in the figure is assembled with initially uncharged capacitors. A potential difference, Vab = +100V, is applied across the network. The switch S in the network is kept ...
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70 views

Is the elementary charge really a constant of nature? - Accuracy of QED

There are a couple of natural constants; examples are Planck's constant or the Speed of light in vacuum. The elementary Charge is the coupling factor to all Kind of electromagnetic interactions; this ...
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36 views

Why are trampolines more likely to give you a static shock when it is sunny?

It could just be in my head but I have noticed that I am more likely to get a static shock from my tramp when it is sunny than when it is not sunny. Is there a reason for this?
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29 views

Is the following thought experiment about two charges correct?

Let's say I put a charge at a point in space for a long enough time. During this time interval it has set up the electric field in the space. Then I put another charge in the space. Since the ...
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1answer
323 views

What proved Conventional sense wrong?

What fact proved for the first time that the conventional sense of current was wrong? And when it did happen? As a corollary of this question, why do we say that electrons have negative charge? Is it ...
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80 views

In string-net condensation, what does the quantized charge means? [closed]

The electrical charge is quantized strictly for elementary particles. What kind constraints does this fact applied to string-net theory? For the this question, I want to understand why electrical ...
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1answer
54 views

Semiconductor intrinsic carrier concentration is given by ni=BT^(3/2)*exp(-E/2kT), how is this derived?

The glorious book Sedra/Smith Microelectronic Circuits states that for a semiconductor the intrinsic charge concentration is is given by: $$ n_i = BT^{3/2}e^{-E_g/2kT} $$ Where $n_i$ is the ...
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77 views

How the experimental charge $e=1.60217657 × 10^{-19} C$ has precisely this value?

The coupling constant that we measured in "arbitrarily" low energy is $e=1.60217657 × 10^{-19} C$. How this is presented in Renormalization Group flow in charge coupling space? Why the action of the ...
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71 views

Electrostatics Basic Question

Why ,if we increase the charge on a conductor its potential also increases? That is, Q directly proportional to V. Why ,if an insulated conductor is given some charge it acquires a certain ...
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1answer
30 views

What does “touching” mean in the context of charge by conduction in electrostatics?

So in our physics class today, we had a demonstration involving a charged rod and a neutral ball attached to a string (a physical pendulum). At first, when the rod was placed near the ball, the ball ...
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1answer
26 views

charge density is a constant or a scalar-value function of position?

Since it is "density", I suppose that such values as charge density of a volume region $\rho_v$, charge density of a line $\rho_L$, and charge density of a surface $\rho_S$ is a constant but I ...
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2answers
144 views

Can one proton attract two electrons?

Suppose that in an empty space there is only one proton. This proton would have created a field of positive charge which should attract possible negative electrons, so now we add two electrons on ...
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1answer
50 views

Repulsive force between same charged plates?

I understand that the attraction force between parallel plates of capacitor is the derivative of stored energy with respect to distance of the plates. But how could we find the repulsive force between ...
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1answer
63 views

Why does Ampère's force only linearly depend on the distance between the two wires?

When we encountered Ampère's force law our professor stated: In the formula of the magnetic force you don't find $r^2$ as in the gravitational and the electric one because while those directly ...
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1answer
33 views

2D room with electron-point-charges (stability)

Is there a fast way to find out stable #"point charges" & constellation for this kind of Simulation. The 2D repeating itselve in each direction till infinity, so i've a kind of symetrie here. ...
2
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1answer
84 views

Charge operator for Dirac spinor

In QED, the gauge transformation which acts upon a fermionic field $\psi$ is $$\psi'(x)= e^{i \alpha(x) Q}\psi(x)$$ where $Q$ is the charge operator. Most of the time it's just written as $$\psi'(x)= ...
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1answer
35 views

Is it possible for the phase of electric charge to change over large general relativistic distances?

Jackson provides examples of how magnetic charge and electric charge form together to create complex charge, \begin{align} \rho = \rho_e+i\rho_m \end{align} which gives rise to the complex faraday ...
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61 views

How to theoretically determine electric charges of $W^{\pm}$ bosons?

I just realised that I don't remember how to conclude theoretically that $W^{\pm}$ bosons have electric charges of $\pm 1$. After some searching I'm quite surprise that I couldn't find a satisfying ...