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

learn more… | top users | synonyms

1
vote
2answers
56 views

How do two electrical charged particles know to repel or attract each other?

Now per QED, electrical charges interactions are effected by photons. Suppose you are one of the two charges. How do you know to attract or repel the other charge? In other words, how do you know if ...
1
vote
1answer
52 views

Is charge transfer from A to B positive or negative?

I see this term pop up a lot -- for instance "charge is transferred from atom A to atom B", but it's never specified whether they're talking about positive or negative charge. I know electrical ...
2
votes
1answer
32 views

Charge density and space inversion

J. D. Jackson in his book Classical Electrodynamics on page 249 ff. discusses the behaviour of electromagnetic quantities under space inversion (parity operation) and time reversal. He remarks: ...
0
votes
2answers
40 views

Relation between electric field and dipole moment

I want to show the following equality $$\int_{\left|\vec{r}\right|<R}d^3r\vec{E}\left(\vec{r}\right)=-\frac{\vec{p}}{3\epsilon_0}$$ where $\vec{p}$ is the dipole moment of a charge distribution ...
0
votes
1answer
30 views

What are the consequences of connecting a non-ideal conductor to a battery in open loop?

Suppose I have a battery with $\Delta V=5[\mathrm{V}]$. Now I connect a piece of a metal wire to the "+" side of the battery only. Let's assume that the ambient air is not conductive at all: Are ...
1
vote
3answers
236 views

Why capacitance is given as constant value in Farads, and not as max charge in Coulombs?

The equation for capacitance is $Q=CV$ or $V={1\over C}Q$. I don't understand what is the physical meaning of this "$C$": Does the charge in a system changes linearly with voltage under all ...
1
vote
1answer
37 views

Exact Relation between voltage and current [duplicate]

I apologize before hand if this seems too naive. I'm having a really tough time understanding the relation between voltage and current. I read that 1 Volt is the amount of work done to move a $1As$ ...
0
votes
2answers
46 views

Why is quasineutrality required for a gas to turn into a plasma?

Why is quasineutrality a required condition for a plasma to exist? Quasineutrality means that no density of electrons and ions should almost be equal but not exactly equal. Can anybody explain this ...
1
vote
2answers
131 views

Magnetic force as a relativistic effect?

There is something I am confused about when it comes to the force between two parallel wires carrying current, specifically why when they carry current in the same direction the wires are always ...
0
votes
1answer
48 views

Stopping current and Maxwell equation compliance

Preamble: Mathematically, the divergence of an eddy field is zero, thus for the magnetic field $$\nabla\cdot\nabla\times\boldsymbol B = \boldsymbol 0$$ and from the $\nabla\times\boldsymbol B$ Maxwell ...
0
votes
1answer
23 views

How do I determine the electric charge on two (initially discharged) spheres after an impact with a charged sphere?

This is the first part of a problem on my book: Two identical conducting spheres, initially discharged, of mass $ m = 0.5 \ kg $ come in contact, in consecutive moments, with another sphere, ...
1
vote
0answers
36 views

Electric field in a “concave” conductor

I am aware that the electrons are distributed across charged conductor surface so that the areas with smaller radius of curvature have more charge per surface area. But what happens when the ...
1
vote
1answer
24 views

a charged particle path [closed]

A particle of mass $m$ and charge $e$ enters a homogeneous and stationary electric field $E$ with velocity $v_0$ perpendicular to the direction of the field. Calculate the particle's path? What does ...
2
votes
3answers
92 views

Self-energy of electron from classical reasoning

If it takes energy to group charge together(self energy) how can it be possible for every single electrons, etc, to have exactly same amount of charge? (think of if we hold some sand in our hand, then ...
0
votes
0answers
57 views

Metal with the biggest positive and negative charge per atom (ion)

Which metal has the highest positive and negative charge per atom? i know that Arsenic can have a positive charge of +5 and negative charge of -3 but is there any metals that can have more electric ...
0
votes
2answers
49 views

Is it possible for electrons to carry more than one charge?

Sorry if this has been asked before. Could also be a really basic question (new to electrical study). I am a bit confused about the relationship between electrons and charges. So what I understand is ...
0
votes
0answers
30 views

Why are there only 2 types of charges? [duplicate]

Why is there only 2 possible types of charges positive and negative? Can there be more, the same way there might be more than 3 spatial dimensions?
0
votes
1answer
74 views

Using Cosine Law to Find Net Electric Force on Charge Always Results in Positive Number?

In order to determine the net force other charges have on a particular charge, you must take into account each individual electric force between the charge and the charge of interest. However some of ...
0
votes
1answer
35 views

What underlying structure/framework defines the charge of an antiparticle or regular particle (specifically a proton)? [duplicate]

I can't seem to find an answer to this. For a given configuration, say for a Hydrogen atom: the proton has properties which give it a positive charge. This is a known truth. Now lets take Hydrogen's ...
1
vote
3answers
47 views

Uses of Static Electricity

Is it possible to store static electricity in any type of battery and can they be used in electric appliances(light,bulbs mainly)?
0
votes
1answer
39 views

Parallel plate capacitor

How does a parallel plate capacitor emit a constant electric field between its plates? Isn't the electric field governed by an inverse square law? Then what would happen if I put a charged particle ...
0
votes
1answer
97 views

Description of the motion of the COM of a system of charged particles moving in a magnetic field

I recently came across a problem where an electrically neutral particle is at rest in a uniform magnetic field. The particle now splits into two charged particles of equal mass $m$; charge and mass ...
0
votes
3answers
44 views

What stored charges do in a capacitor? [closed]

Why does a fan need capacitor? Capacitor is just providing charges to fan but it can be accomplished without it by directly connecting fan with electric supply. Which other appliances need capacitor?
1
vote
1answer
37 views

Does magnitude of a charge influence magnitude of force that individual charge exerts on another charge [closed]

two point charges, q1 and q2, are placed 0.3m apart on the x-axis, as shown in the figure above. Charge q1 has a value of -3 nano Coulomb and q2 has a value of +4.8 x10^-8 C. The net electric field ...
2
votes
2answers
70 views

Is a given charge density a surface charge density or volume charge density?

The exact question goes like this: In a certain electronic tube, electrons are emitted from a hot plane metal surface, and collected by a plane metal plane parallel to the emitter, at a distance ...
8
votes
1answer
177 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 ...
0
votes
0answers
26 views

Determining if an object is dielectric or metallic

In a worksheet I was given, I had to find the net electric field of P which is L distance away from a bar. The last question is ...
0
votes
1answer
312 views

Gauss Theorem:Electric field of an uniformly charged non-conducting spherical shell

I want to know the electric field of an uniformly charged non-conducting spherical shell. I know that in case of conductors(metals),the sphere can be shell or it can be solid,but in both the cases ...
1
vote
2answers
58 views

Draw the charge configuration according to the electric field [closed]

I'm trying to draw the charge configuration outside the regions that lead to the given electric field patterns. Can someone show me how?
0
votes
1answer
70 views

Gauss's Law :Electric field due to uniformly charged sphere

While determining the electric field due to a uniformly charged conducting or non-conducting sphere,does the sphere is considered hollow or it is considered solid? Can anyone really state , what is ...
1
vote
0answers
9 views

Would the charges on a superconductor near an another charged conductor move and produce magnetic field?

When there is a charged conducting object near an another charged conducting object the charges on these objects accumulate to the sides where the closest points between these objects are. However, ...
2
votes
1answer
62 views

Electric charge of light? [duplicate]

Light (or any radiation as a matter of fact) is an electromagnetic wave so why doesn't it have a electric charge associated with it? As far as I know only static or flowing electric chargers can ...
0
votes
2answers
60 views

What is the difference between electric charge and electric flux?

What is the difference between electric charge and electric flux? According to my knowledge electric flux is nothing but electric charge enclosed by the closed surface.
6
votes
3answers
343 views

Why are there no elementary charged, spin-zero particles?

In the spirit of a related inquiry, I would like to know if there's a basis for understanding why there aren't any elementary particles that have non-zero electric charge but zero spin? Can such a ...
1
vote
0answers
43 views

Charge distribution over a finite plate

Let's say we have a tube(simply a cylinder with no top or bottom) with charge $q_1$, radius $r_1$ and length $l_1$ made out of insulating material. There is also a finite conducting plate with sides' ...
2
votes
1answer
295 views

Why isn't the quark charge taken as primitive?

Why are electrons taken implicitly to be the elementary charge? It would save a lot of fractions in particle physics problems.
1
vote
1answer
62 views

How would the universe change?

How would the universe be modified if protons (as we know them) have negative charge and electrons (as de know them) have positive charge.
1
vote
1answer
38 views

Is the charge of an ion evenly distributed?

This question relates to: Gauss' law and ions? Is the charge distribution in an ion spherically symmetric due to quantum mechanical effects or do we assume it when using Gauss's law, as in the ...
0
votes
1answer
25 views

Gauss' law and ions?

My text book says that with we have a singly ionized sodium atom net charge +e and if we choose a spherical surface centered on the ion and large enough to contain it all we do not need to know the ...
2
votes
1answer
85 views

Charge vs Charge Density in classical electrodynamics

What is assumed to be a more fundamental physical quantity in classical electrodynamics. The charge density as a scalar field or the physical entity charge.
4
votes
1answer
126 views

Electron Charge is 150%?

Is there a theory for why the charge of an electron is precisely 50% larger (magnitude) than a quark's? I have usually thought of this the other way around: the charge of a quark being 2/3 (or -2/3) ...
0
votes
2answers
229 views

How can I split a resultant force into its $x$ and $y$ components?

Point charge 3.5μC is located at x = 0, y = 0.30 m, point charge -3.5μC is located at x = 0 y = -0.30 m. What are (a)the magnitude and (b)direction of the total electric force that these charges ...
0
votes
1answer
33 views

When two spheres of equal charge make contact, why does the larger sphere gain more charge?

Suppose that two spheres, $S1$ and $S2$, with radii $R1$ and $R2$ resp. have the same charge uniform charge $Q$ and $R1 > R2$. After they are forced to come in contact, why does $S1$ gain more ...
2
votes
2answers
41 views

Unequally charged hanging pith balls

I have done a problem which asks us to find the charge on two equally 'massed and charged' pith balls which are left hanging on a string with a certain length that repels each other and attains an ...
1
vote
1answer
50 views

How to distribute static charges evenly on a finite plate?

There are several ways to make charges on an object evenly distributed. For example, if the surface of the object is infinite or the object is a sphere. There is one more way which I am not sure if it ...
1
vote
3answers
88 views

How can metal objects become electrically charged, if current flow means that an equal number of electrons enter/leave the object?

I am trying to answer to the question in the title. I am restricting my question to metal objects only. Here is my logical reasoning: Current is the flow of charge over time. In a circuit (simple ...
4
votes
1answer
245 views

Understanding the Charge Conjugation Operator

I am trying to understand the charge conjugation operator. http://en.wikipedia.org/wiki/C_parity Because the operator is Hermitian, this seems to imply that there is a (possibly spontaneous?) ...
2
votes
2answers
41 views

Do charges flow from strong insulator to weak insulator?

Do static charge in a strong insulator flow to a weaker insulator when both stay in contact with each other? For example, when an insulator weaker than air placed in a medium of air, would the static ...
1
vote
1answer
43 views

How to find whether the electric field between capacitor plates is above or below the electrical breakdown limit of the insulator between the plates?

Let's say the two plates of a capacitor have charges $q_1$ and $q_2$. The separation between these plates is $d$. I know that I can calculate the electric field by dividing the voltage that is applied ...
2
votes
2answers
70 views

How much voltage should be applied to an object to create a certain amount of charge?

I am curious as to how much voltage should be applied to create a specific charge. Is there a formula to calculate it, and what are the parameters that can affect the relation between voltage and ...