Electrostatics is concerned with the electrical fields and scalar potentials of stationary electrical charges and charge distributions. Use this for questions about electromagnetic situations in which currents and magnetic fields are absent, otherwise use [tag:electromagnetism] and/or ...

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Will charge transfer without friction

I know rubbing two objects of different materials together will result in a negative charge on whichever material has a higher electron affinity. However, I was wondering if a negatively charged ...
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3answers
72 views

Nonlocal dielectric function - what does it mean?

I'm reading this* article and in the second sentence of introduction I encountered a term I haven't heard of before. Namely: nonlocal dielectric function. What does this nonlocality mean? And how does ...
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599 views

Confused medical student needs explanation of the electrocardiogram

From what I understand, as the heart depolarizes it turns into a lot of electric dipoles , the resultant of which can (somehow) be measured in the extremities. But how does this actually happen? How ...
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2answers
79 views

An IE IRODOV Electrodynamics problem

A ring (radius R) is given a negative charge -q and at the centre a positive charge +q is kept. We have to calculate the electric field on the axis of the ring at a distance X from the centre. Take ...
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1answer
34 views

a point charge is kept at the centre of a metallic inducted spherical shell.then why the net induced charge on the sphere is zero?

Why the net induced charge is 0 in a inducted spherical shell when a point charge is kept in the centre of that sphere?
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4answers
218 views

How to calculate the work of the electrostatic forces in a parallel-plate capacitor?

The expression of the energy stored in a parallel-plate capacitor is: $$U = \frac{e_0\cdot A \cdot V^2}{2d}$$ with $e_0$ the vacuum permittivity, $A$ the surface of the capacitor, $V$ the applied ...
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1answer
62 views

Simple question regarding Gauss's electric law

I just read that electric flux=enclosed charge/permittivity. Considering the charge in an enclosed surface is always 0, what is the point in even having this equation? Or is the equation actually ...
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1answer
100 views

In the case of two equally charged particles, is the electric field between them incompressible?

When approach two electrons (or two protons or ...), the electric fields do not merge and stay isolated from each other. Which I borrowed from here. Is it right to conclude that in the case of ...
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1answer
49 views

Electric potential of a sphere at a point on its surface

I'm struggling to figure out how to determine the infinitesimal area of the sphere given in the question. More specifically, in part (b) of the question. For part (a) it's the volume so $$V = ...
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3answers
325 views

Flux through closed surface

My class teacher says charge kept outside a closed surface will not hold any flux because number of field lines entering are same as number of field lines exiting. But when I imagine sufficiently big ...
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0answers
84 views

Charging by induction and capacitors

Consider a material having high dielectric constant say A which is in the shape of a plate.Now place two metallic plates on opposite sides which do not cover the whole surface of the dielectric say ...
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1answer
98 views

dipole-dipole interaction

U= -p(vector of one dipole)*electrict field due to the second dipole does this equation give the energy of one dipole due to the electric field due to the second one, if so is the total ...
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5answers
136 views

Flux of $E$ through the shaded side

A charge $q$ sits at the back corner of a cube, as shown in Figure. What is the flux of $E$ through the shaded side? One of the solution stated that. Looking at the figure, we notice two ...
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1answer
56 views

Electrostatics - wire electric field symmetry

I was just wondering about the final part to do with the symmetry of the wire. In what circumstances would the wire not emit a field that's uniform? Would the wire have to be thick in some parts and ...
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1answer
59 views

Classic Electrostatics Image Problem Surface Charge

In the classic image problem of Electrostatics (an infinite conducting planar sheet and a point charge above the sheet), one calculates the potential and hence field in the region above the conducting ...
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1answer
199 views

Electric field a distance z above the midpoint of a straight line segment

In Griffiths there's an example to evaluate the Electric field a distance z above the midpoint of a straight line segment of length 2L. Which carries a uniform charge $\lambda$. In that calculation, ...
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1answer
1k views

Magnetic field inside parallel plate capacitor

Inside a parallel plate capacitor, we know that the electric field due to the static charge $E= \frac{\epsilon_0 A}{d} $ Now if we want to find the magnetic field inside the parallel plate capacitor, ...
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0answers
16 views

Voltage developed along the length ofan accelerating conductor?

Does a conductor become polarized when accelerated? Starting with a conductor that is neutral and polarized. Electrons are evenly distributed within the volume and do not feel any net electric field ...
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2answers
192 views

Magnitude of a dipole moment [closed]

I am now learning Electromagnetism, and I am doing the practice question. However I am stuck in the following question. A uniform electric field has a dipole placed in it. If you rotate the dipole ...
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1answer
96 views

Why do charges move at the rim of the “charged-disk” conductor in response of the field created by themselves?

Okay, one statement from Purcell's book goes like: [...]Thus, we find the potential at $P_2$: $$\phi = \frac{1}{4\pi\epsilon_0} \int_{-\pi/2}^{\pi/2} 2\sigma\cos\theta d\theta = \frac{\sigma ...
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1answer
42 views

In magnetostatics, is there any relation between flux and current?

I have noted while trying to find analogy between electrostatics and magnetostatics, for the equation, flux = charge/epsilon, is there any corresponding equation in magnetostatics, relating magnetic ...
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0answers
21 views

In electrostatics, what is the actual relation between flux density and flux

I know, in magnetostatics, unit of flux in webers. And unit of flux density B is webs per metre square. its clear. Now in electrostatics, unit of flux is volts metre. And unit of flux density D is ...
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37 views

Can a flowing gas create a static charge?

On the Static Electricity page of Wikipedia the claim is made that "The flowing movement of gases in pipes alone creates little, if any, static electricity" with a cited reference [ref 19] being made ...
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1answer
47 views

Breakdown field in a capacitor

Let us say that air breaks down at a field strength of $E_b$. For a capacitor to arc, does there need to be a path between the two conductors such that for every point on that path the electric field ...
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1answer
64 views

Electric field at location of a charge due to the charge itself?

Suppose a charge $Q$ is put in the space at point $(x',y',z')$. What is the electric field value at point $(x',y',z')$?
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1answer
133 views

Surface bound charge in the electric displacement

In Griffiths, the electric displacement is written with just volume charge density, and that is because, he says, 'we cannot apply gauss law precisely at the surface of a dielectric, for here volume ...
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1answer
45 views

Can we charge any two bodies (insulators) by rubbing?

I am not talking about the usual glass rubbed with silk rather any two insulators found in nature. If we rub them, will they get charged? Like cotton and plastic etc.
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1answer
85 views

Will two touching, neutral conductors in an electric field separate?

If you put two square, neutral conductors in the middle of a uniform electric field such that they are touching, will they separate? I thought yes. When they are touching, as shown in the picture, ...
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1answer
54 views

Why does flux in closed surface remain constant if exterior charge is altered?

Q. Charges $q_1$ and $q_2$ lie inside and outside respectively of a closed surface $S$. Let $E$ be the field at any point on $S$ and $\Phi$ be the flux of $E$ over $S$. One of the answer is: if $q_2$ ...
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1answer
42 views

Will ionization energy be affected by screening effect?

It would be logical to think that the more electrons are ejected from an atom, the harder it is to eject more. I just learned about photoelectric effect experiment. The book is kinda telling me the ...
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1answer
46 views

Meaning of “electrostatic” and “nonresonant laser” fields

I just read the following sentence: The molecule is subjected to an electrostatic field $E$ combined with a nonresonant laser field of intensity $I$, whose linear polarization is collinear with ...
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1answer
45 views

Stability and Laplace's equation

Consider four positive charges of magnitude $q$ at four corners of a square and another charge $Q$ placed at the origin. What can we say about the stability at this point? My attempt goes like this. ...
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3answers
206 views

Drawing the lines of force for an electric field varying in magnitude but having a constant direction

How will the electric lines of force look for an electric field varying in magnitude but having a constant direction, say along +ve z axis ? According to me, since the electric field is varying in ...
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1answer
82 views

Induced charge on a shell

If a charge +Q is placed off-center inside a neutral conducting shell,can we comment that the charges induced on the inner surface is such that the net force on the +Q charge is zero?If so,how?
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1answer
74 views

Capacitor and Pith Ball experiment

Suppose I first charge a capacitor so that one plate is positively charged and another negatively. Now I remove the charging source and ground only one of the terminals say negative terminal, will ...
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3answers
190 views

How can flux be the number of electric field lines normal to a surface? [duplicate]

Shouldn't the number of field lines through any surface be infinite if there is a charge present. Or is there a finite number of field lines from a unit charge?
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2answers
74 views

How is electric dipole moment analogous to mechanical moment?

Diplole moment is q*2l. I don't understand the similarity between dipole moment and ordinary mecanical moment.
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1answer
253 views

Concrete example of the application of complex analysis in electrostatics [closed]

I've heard complex analysis can be useful in solving electrostatics problems, but despite doing some research I was unable to find any concrete examples. Would anyone be able to provide a simple ...
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1answer
157 views

Finding the electric field of a NON uniform slab? [duplicate]

If we have an infinite slab that is not uniformly charged and is not a conductor, how can we find an expression for the electric field everywhere? Here's a picture Things we know about the slab: ...
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1answer
45 views

How will open-circuit voltage affect the Fermi Level Difference

The circumstances of my question consists of this: I have two materials, copper and cesium, and they are sandwiched together with a layer of cesium in the middle. It is connected only on a single side ...
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2answers
60 views

where has the energy gone when the test charge turned away?

Consider an insulated ball with some charge $q_1$ inside it.Now we take a small area over that ball uninsulated i.e we had cut a small portion. Now when we bring a test charge from infinity near that ...
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1answer
91 views

Work Function Calculation with Local Electrostatic Potential

On the Wikipedia site, it describes the work function equation as W = -e\phi - Ef, where phi is the electrostatic potential of a vacuum nearby the surface of the material. So my question is, how can I ...
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2answers
168 views

Electric field in a non-uniformly charged sheet [closed]

So if we have a large sheet that is not uniformly charged and is NOT a conductor, how can I find an expression for the electric field everywhere? Things we know about the sheet: the width is 2b it ...
0
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1answer
167 views

Minima & maxima of Laplace's equation

I don't get the following sentence from David J. Griffiths' Introduction to Electrodynamics (the ambiguous sentence is in bold) Laplace's equation tolerates no local maxima or minima; extreme ...
2
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3answers
168 views

Zero current induced in a loop

Consider the following two cases, Case 1 – A coil moving through a constant magnetic field Case 2 – A conductor moving through a constant magnetic field Now, in Case 1 (a coil moving through a ...
2
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1answer
34 views

variation of electrostatic potential on moving radially outwards from the nucleus of an atom

I was wondering how would the electrostatic potential change on moving radially outwards from the nucleus in an atom, considering the effect of the electron clouds around it.
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0answers
28 views

Comparison of capacitances

The figure shows two arbitarily shaped surfaces S1 and S2.S1 is a thin metal foil, which has been slowly beaten to form the surface S2 without any loss of charge.. S2 lies completely within or on ...
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2answers
24 views

Nucleus validation [duplicate]

Inside the nucleus of an atom is the Coulomb's law valid? I mean that between proton, neutron and other elementary particles, i.e., meson etc. What will be the limit or validity of charges between ...
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1answer
54 views

Electric Fields in a Neutral Object

A neutral object has no net charge since its positive and negative charges cancel each other. However, I’m wondering how, in terms of fields, they do cancel each other. Since fields are vectors, won’t ...
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2answers
62 views

Do anodes emit virtual photons representing their positive electrostatic potential?

I understand the electrons in circuit travel down the path of least resistance, however are electrons attracted by the emission of virtual photons emitted by a source with relatively low electron ...