# Tagged Questions

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 [tag:magnetic-...

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### 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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### 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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### 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 things: ...
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### 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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### 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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### 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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### 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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### 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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### 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 ...
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 a}{\... 1answer 48 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 ... 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 ... 0answers 53 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 ... 1answer 50 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 ... 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')? 1answer 167 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 ... 1answer 48 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. 1answer 96 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, ... 1answer 55 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 ... 1answer 43 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 ... 1answer 48 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 ... 1answer 49 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. ... 3answers 258 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 ... 1answer 113 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? 1answer 78 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 ... 3answers 225 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? 2answers 81 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. 1answer 284 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 ... 1answer 170 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: ... 1answer 51 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 ... 1answer 75 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 make 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 ... 1answer 114 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 ... 2answers 209 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 ... 1answer 199 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 ... 3answers 208 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 ... 1answer 35 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. 0answers 29 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 the ... 2answers 25 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 ... 1answer 55 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 ... 2answers 65 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 ... 2answers 114 views ### When is work done on or by something? An example, here what my textbook says: When charges are released In electric fields charges experience the force causing them to accelerate along electric field vectors. Positive charges ... 1answer 105 views ### Electric field between capacitors [closed] A parallel-plate capacitor consists of two parallel, conducting plates of area A, separated by a distance d. Each carries a charge of magnitude Q; positive on one, negative on the other. Using ... 1answer 543 views ### Determining potential in coaxial cylinders If I have two conducting, coaxial cylinders as shown: The potential at the outer cylinder is = 0. And I apply a potential difference across both cylinders in the form V_a - V_b = V_{ab}, how can ... 2answers 41 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}. 0answers 19 views ### Why the magnitude, E, of the field vector is different for every sets of (parallel) plates? This is quoted my textbook. I wonder why we can't reproduce the same magnitude on a different set of plates, if we make them the same size, same charge, and having the same electric potential, and ... 1answer 74 views ### Is the sea of electrons in a metal at rest when the metal is in electrostatic equilibrium? It is said that charges inside a metal in electrostatic equilibrium are at rest, and are stationary. However, don’t the electrons have their own thermal vibrations and whatnot? Aren’t they always ... 1answer 63 views ### Earnshaw's theorm and Effective potential Earnshaw's theorm says "no stable equilibrium for any \frac{1}{r} potential field in charge-free space". Now I am confused in some aspects, and I would like some helping hands. 1.)General physics ... 1answer 406 views ### Why isn't the electric field zero in the empty space? A spherical portion has been removed from solid sphere having a charge distributed uniformly in its volume the electric field inside the emptied space is? Isn't the electric field suppose to be zero ... 1answer 27 views ### Why does power loss in pure metal caused by temperature is calculated base on P=I^2R but not \frac{U^2}{R}$$P=I^2R=\frac{U^2}{R}$$The metal's resistivity is temperature dependent, neglect the change in size by temperature. The power loss of a pure metal when it drop form temperature T_1 to T_2 is$$...
The Maxwell's equation $\boldsymbol{\nabla}\cdot \textbf{E}(\textbf{r})=\frac{\rho(\textbf{r})}{\epsilon_0}$ is derived from the Gauss law in electrostatics (which is in turn derived from Coulomb's ...