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

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1answer
15 views

Net force on particle 1 due to particle 2 - Express your answer in vector form [on hold]

I am trying to work out the correct answer for an online physics quiz, but nothing I try seems to be correct. The question is: Consider two positively charged particles, one of charge $q_0$ ...
1
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1answer
121 views

Upper limit to electric charge confinement?

The following questions are not intended for conventional capacitors (which stores excess charge on the outside surface), rather a type of hypothetical capacitor which is designed to confine charge by ...
1
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1answer
279 views

Force due to combination of free space and dielectric

I will make a generalized form of my question. There are two point charges $q$, $x$ distance apart. And there is a dielectric slab of thickness $t$ and of dielectric constant $K$. Should the force ...
3
votes
2answers
34 views

Force on non-moving charge in solenoid with increasing magnetic field

The problem: "Through a solenoid there is an increasing magnetic field $B$. For a positively charged particle not in motion, what is the direction of force on the particle?" Normally a non-moving ...
4
votes
1answer
432 views

Semiconductor problem: how much Boron is required to establish a certain amount of charge carrier density

The problem description is as follows: Boron is used to dope 1 kg of germanium (Ge). How much boron (B) is required to establish a charge carrier density of 3.091 x 10^17 / cm^3. One mole of ...
1
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1answer
42 views

Charge of $W$-bosons in Feynman diagrams

When looking at Feynman diagrams of particle decays, how would I be able to find out the charges of the $W$-bosons involved in the decay?
2
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6answers
7k views

Why do we test electric fields with positive charges and not negative ones?

Is there any difference between using a positive versus a negative charge to test an electric field?
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2answers
38 views

Is this diagram in my textbook not constructed to scale?

Or am I having an illusion. Clearly, the distance from 6v to 4v is not the same as 4v to 2v. I know it should be based on: $V = k\frac{q}{r}$.
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1answer
23 views

How does the size of conducting sphere affect the distribution of charge?

I am doing my homework. One question gives individual charges on two spheres. And asks what the resulting charge is on each after touching. But one thing interest me is that in the answer key, it's ...
0
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1answer
18 views

Why can't objects made of insulating material “store excess charges”?

This is quoted from my textbook. I saw plastic objects before being able to store excess charges. For example, if you rub paper against a plastic pole. Both will gain charges. But in lab, I never ...
3
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3answers
260 views

Why do many books say quasineutrality is needed for a plasma to exist?

Many books on plasma physics (Chen, Goldston, Lieberman) say that quasineutrality must be satisfied for the matter in question to be a plasma. Yet, we know that non-neutral plasmas exist. So why do so ...
0
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1answer
14 views

Would an electroscope work if it were not in a glass container?

I'm reading about the gold-leaf electroscope and all the sources I've read show that the gold leaves are placed in a glass container. Is there something special about the glass, or would any container ...
8
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3answers
947 views

why dosen't a charged particle radiate energy in circular motion in a uniform magnetic field?

I have studied in my Physics course that one of the drawbacks of Rutherford's atomic model was that when an electron will revolve around the nucleus, it is undergoing acceleration and so it should ...
0
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0answers
44 views

Does voltage depends on the charge present in an element?

Does the voltage depend on the charge present in a battery ? I know in capacitors q=cv. Hence charge present is proportional to voltage. Is it the same in the case of batteries?
1
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1answer
82 views

Principle of superposition and QED

For finding a net force on a charge when it is in influence of many charges we simply do vectorical addition of all individual interaction of that charge with others. That's what is principle of ...
0
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1answer
128 views

Opacity/Transparency of Conductive Meshes to Charged Particles (Electrons/Ions)

When using a conductive (metal) mesh, effectively a metallic woven fabric, in vacuum applications as a "grid" for charged particle optics, how does one calculate (or at least estimate) the opacity or ...
0
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1answer
51 views

What are the interpretations of ampere's circuital law for a single moving electron?

I understand from Ampere's circuital law that when a current passes though any open surface with a boundary (a circular boundary, for simplicity), then limit of summation of the scalar products of ...
0
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0answers
19 views

Why is Ampere not a derived SI unit? [duplicate]

From my understanding, Ampere is amount of elementary charge per time. So, you should be able to derive it from mol, which is amount, and seconds, which is time. My question: Why is Ampere a base ...
2
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1answer
28 views

If you charge water will the evaporation rate change?

If you take away electrons or add electrons to a body of water will the evaporation rate be changed? (Even if it's brief or the effect is small)
2
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1answer
27 views

Are Cosmic Rays net neutral in charge?

As I understand them, Cosmic rays mainly consist of high energy charged particles. I began to wonder if they would eventually net charge the Earth and then assumed that they must come in roughly ...
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2answers
25 views

A circuit that is net charged

What differences would you measure if a circuit were significantly charged negatively? Would the resistance change? To be clear, I mean that excess electrons are added to the system. The circuit can ...
0
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1answer
51 views

Force Acting on a Charge Between Parallel Plates

When a charge (say positive) is placed between an upper positively charged plate and a negatively charged plate, it should experience a repulsive force from the top plate and an attractive force to ...
0
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1answer
38 views

Grounding a capacitor

When one of the plates of an isolated capacitor is grounded, does the charge become zero on that plate or just the charge on the outer surface become zero?
-4
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1answer
56 views

Can the fundamental dimension of Electric Charge be Mass only? [closed]

After solving dimensions of electrical equations, I found out that the fundamental dimension of Electric charge is mass only. This also leads to the derivation of dimensions of other Electrical units ...
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1answer
104 views

Does charge of a metal charged by induction determine by which ends of the metal is grounded to?

Does charge of a metal charged by induction determine by which part of the metal is ground to? I draw a diagram to make it simple to understand: Right diagram: When ground is touched with the ...
2
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1answer
106 views

What happens to charge during laser ablation in water?

One of my friends from lab makes gold nanoparticles in the following manner: He puts a gold plate in water (without surfactants or other additives) He fires laser at the plate After 5 minutes ...
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3answers
163 views

Can two electrons attract each other?

Due to electrostatic repulsion the two electrons will repel each other as they both possess similar charges, lets leave gravitational attractive force out of the picture my question is can there be ...
5
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4answers
1k views

Charge of an electric wire

If an electric current is flowing through an electric wire, can we consider that wire charged? The answer is required with a proof. Can we consider the wire to be charged positively or negatively?
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1answer
20 views

Is $\kappa_e$ caused by charge-carrier transport or electron transport?

$\kappa$ usually symbolises thermal conductivity, a material's ability to conduct heat. $\kappa$ can be expressed with other partial thermal conductivities: $\kappa=\kappa_e+\kappa_{ph}+...$ where ...
2
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2answers
85 views

Force between two point charges moving parallel to each other

When we observe two point charges moving parallel to each other we can see two forces acting on each of the charges: the Coulomb force the magnetic force ($\mathbf{F}=q\mathbf{v}×\mathbf{B}$) ...
0
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0answers
22 views

Variations in electric field of a light speed charged particle

From the question " Is there a travelling speed of for electric field? If yes, what is it?" I get to know electric field propagates at speed of light. What if a charged particle which creates this ...
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1answer
60 views

Derivation of magnetic force for a charge in motion relative to a wire (M. Purcell's Electricity and Magnetism)

I have a question regarding the derivation of magnetic force in M. Purcell and David Morin's Electricity and Magnetism. In the first part, they derived the force first by assuming that a charge q is ...
0
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1answer
96 views

How does a minority carrier diffuse?

I have gone through a lot of questions but none of them ask how do the minority carriers approach the depletion layer in the first place. When a p-n junction is formed, negative space charge ...
0
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0answers
17 views

How would a closed conductor with only 1 layer of (atoms/molecules) behave if a charge is placed inside it?

I have quite a few questions actually related to this . Is it possible to have such a situation practically? If theoretically possible, how would the system behave?
0
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0answers
18 views

Total current - differential equation [duplicate]

Consider the circuit below consisting out of a capacitor C and two identical resistors R. For $t<0$ the switch is open and the capacitor is uncharged. At $t=0$ switch is shut and the circuit is ...
0
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1answer
54 views

Circuit with capacitor and two resistors - total current - charge - differential equation [closed]

Consider the circuit below consisting out of a capacitor C and two identical resistors R. For $t<0$ the switch is open and the capacitor is uncharged. At $t=0$ switch is shut and the circuit is ...
0
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2answers
790 views

How do I express the interaction energy between two charged spheres?

Consider two identical insulating spheres each with radius $R$ and uniform charge $Q$ through their volume. They are separated from their centers by a distance of $d>2R$. Here is my general ...
0
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0answers
29 views

How do scientists measure miniscule constants like the mass and charge and speed of an electron?

What can measure the extremely tiny mass of an electron? Is it through indirect means? The same goes for charge. The pull of a single electron must be infinitely small. And if one is to attempt to ...
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1answer
49 views

If Coulomb and Esu have different dimensions, why can we convert simply by 1C= 3*10e9 esu?

I was always told in school we cannot convert an apple into a potato, so we have to have the same dimensions on both sides. When converting coulomb to esu, we do not seem to bother with dimensions. ...
10
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2answers
405 views

Is electric charge truly conserved for bosonic matter?

Even before quantization, charged bosonic fields exhibit a certain "self-interaction". The body of this post demonstrates this fact, and the last paragraph asks the question. Notation/ Lagrangians ...
3
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4answers
269 views

The electric field in wires in a circuit

I have a hard time really understanding the electric field in a complete curcuit. How is the electric field maintained throughout the wiring / the conductors from component to component? The charges ...
4
votes
1answer
61 views

Why is $U(1)$ special when defining global charges?

For gauge groups like $SU(2)$ and $SU(3)$ etc. we know that observable states such as mesons or baryons must be charge neutral. However, for a $U(1)$ gauge group we can have charged initial states in ...
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2answers
76 views

Why is the Electric Field Zero at this point?

In a Phet Lab simulation, which is all I have at the moment to do my learning on electric field forces, the point represented as colored on the diagram below is shown to have an electric field ...
0
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1answer
28 views

What is the purpose of defining an electric field, and how to apply it?

So, I've been reading an introductory book to physics. I've gotten to the point where I understand Coulomb's law, and now the book is introducing electric fields. I'm having a hard time ...
0
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0answers
35 views

Calculating rise in water surface due to a charged capacitor

Two metal plates separated by a distance d & initially charged with charge +Q & -Q are kept so that it just touches the surface of a very large water tank as shown in figure a. Thus water ...
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2answers
104 views

Application of Coulomb's Law

I've just finished reading a section in a book on Coulomb's Law. I'm trying to practice the math a bit and came up with the following: Suppose you have two charges, -5uC ($q_1$) and 7nC ($q_2$). ...
0
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1answer
37 views

Can I get help with measuring particle charge using oscilloscope?

How can one measure particle charge using oscilloscope and op amp integrator circuit along with a capacitor and faraday cup. I am unable to figure out how to approach. I have the circuit ready but ...
0
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1answer
70 views

What is the significance of Planck charge?

It seems for me that Planck units are somehow connected to limits where our current knowledge breaks down because of (quantum) gravitational effects. Please correct me if I'm wrong. For example ...
2
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5answers
2k views

Why don't positive charges move?

Charge is carried by electrons moving. The protons are always stationary. The answer I found online is the protons are stuck in the nucleus so they can't move ("strong nuclear force"). But why can't ...
2
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6answers
183 views

Why does accelerating electron emits photons? [duplicate]

I have read that accelerating or oscillating electron emits photons. But why and how does it so? And why only photons? There are other bosons like gluons, W and Z bosons, so why does electron emit ...