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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Do glass beads show any piezoelectric property?

Do glass beads show any piezoelectric property? Since glass beads is mostly made out of SiO2 which is piezoelectric, will it show any piezoelectric property. Thanks. If anything wrong with my ...
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2answers
303 views

Electric potential inside shell

Suppose we have a hollow neutral shell and $q$ charge at $r$ from its center now we take a point a someplace other than center then will electric potential change? I don't think because electric ...
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3answers
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How can I theoretically describe the potential between two capacitors in series?

Suppose to have two capacitors in series: The voltage in the middle point will be: $$ V_X = V_1 \frac{C_1}{C_1+C_2} $$ How can this be explained? It's been asked in electronics, and explained in ...
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4answers
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when we rub objects together, what determines which material will pick up electrons?

For example We know glass when rubbed by silk will become positively charged while the silk will be charged negative. What exactly makes glass appropriate for losing electrons in that experiment? (
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3answers
56 views

How can we assume that we're in electrostatics if we are talking about current?

In the textbook I am currently reading it states that to even out the flow of current throughout a circuit, the force required is of the form $f=f_s+E$ where $f_s$ is from the battery or other energy ...
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5answers
125 views

Physical interpretation of the statement $\oint E\cdot dl=0$

Can anyone provide me with a physical interpretation of $\oint E\cdot d\ell=0$ in electrostatics?
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2answers
85 views

Does zero change in magnetic flux always imply zero emf induced?

If you have a uniform B field, with a finite piece of wire inside it. Assuming the B field spans all space and the wire cannot leave the field. Are you able to create an emf by moving the wire ? I ...
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1answer
32 views

Question regarding 2 conducting spheres connected by a long fine line (electric potentional)

I'm having a bit of trouble understanding a pretty simple issue. Assuming I have 2 conducting spheres uniformly charged connected by a long fine line (as shows in the added photo) and im being asked ...
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0answers
33 views

How to prove that the electric field strength in the interlayer is radial?

This is a structure modified from a typical metal spherical capacitor: half of the interlayer is now filled with one kind of uniform, isotropic, and linear dielectric medium whose dielectric constant ...
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1answer
64 views

Charge inside a shell

There's a positive charge Q inside a neutral conducting shell. An external field is applied. I learned that there can be no effect in cavity due to external things (electrostatic shielding), so ...
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2answers
60 views

Is there such thing as an evenly-charged sphere?

Let's begin with a very typical model seen in almost every electromagnetics textbook: a solid, evenly-charged sphere. First it cannot be a conducting sphere because charge will automatically ...
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1answer
171 views

Circuit breaker Trips during thunderstorm

The circuit breaker at the electrical mains trips at home when there is a thunderstorm outside. Why does this occur?
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3answers
885 views

Why is surface charge distribution uniform for a conducting sphere? Can't it be arbitrary?

If the charge $q_1$ has to repel the charge $q_2$, the electric field has to go inside the conductor which contradicts the fact that electric field inside conductors is zero. Then why do the charges ...
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1answer
37 views

Preventing Electricity Leakage With Insulators

If we charge an object made of insulating material, the charges on it would leak to the medium as the time passes, due to the potential difference. I would like to know if there is a way to prevent ...
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2answers
1k views

Can two electrons never touch each other?

The Coulomb's force is given by $$ F = {k q^2 \over r^2} $$ When $ r \rightarrow 0 $, $ F \rightarrow \infty $ Does this mean two electrons never touch each other?
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0answers
54 views

Electrostatic ion thruster neutralizers

All electrostatic Ion thrusters have a neutralizer electron beam, but why are they required? Is avoiding the accumulation of negative charge the only reason? I would've thought that the main reason ...
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1answer
35 views

Any economical quantitative electrostatics experiments for the university level?

I'm seeking for some safe experiments for undergraduates in the electrostatics context. We have a Van-de-Graaff generator in our fundamental physics lab but this kind of devices are useful for ...
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2answers
652 views

What is charge actually? How to define it? [closed]

Is charge of something for (e.g.) an electron related to electromagnetic space if it exists due to energy, due to which it may have mass? I don't know about quantum mechanics or advanced particle ...
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1answer
51 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 ...
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0answers
22 views

Approximating electrostatic grids as a multipole expansion

Is there a known good summary, or a succinct algorithm to compute the far-field approximations of an arbitrary set of electrostatic surfaces set at different potentials? I'm looking to model a ...
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1answer
70 views

Why is static electricity called static?

They called it "static" because it doesn’t go anywhere. To create static electricity, you have to rub two different materials. At the moment you rub them, the electrons already moved. So how come ...
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2answers
53 views

Is that ground, wall conductive?

If i put my foot exposed to ground and put my finger to the USB power, i will be electrocuted. So the electron(s) from the USB power is passing over my hand, run to foot and go to ground ? As i might ...
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1answer
111 views

The advantages of a dielectric in a capacitor

In a capacitor a dielectric can be placed in between the two plates. I have trouble understanding the points / advantages of a dielectric from what I have read in a text book. The points written there ...
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1answer
46 views

A query regarding constant $\frac{1}{4\pi \epsilon_{0}}$ in Coulomb's Law [duplicate]

In our physics class we were discussing about Coulomb's Law and equation for the electrostatic force between two points: $$F_{e}=\frac{Q_{1}Q_{2}}{4\pi \epsilon_0 r^2}$$ From the equation a query ...
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1answer
30 views

electric charges of metals in electrostatics

In electrostatics does metal gain electrons to be an ion or it conduct electrons in form of gaining them to have a negative electric charge
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1answer
36 views

Electric Field Contributions

Figure 1: Two thin parallel wires Figure 2: The cross section of a hollow sphere containing a smaller, hollow sphere The electric fields for both figures are calculated using different principles. ...
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3answers
805 views

Parallel-plate capacitor

I'm trying to grasp parallel-plate capacitors in a class of electromagnetic field theory. My book leaves out a lot and I couldn't figure it out from what I found on Google. The book's procedure is ...
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1answer
42 views

Influence of a Capacitance Matrix of a voltage measurment

I am having a problem in understanding how in a multiconductor system the Capacitance Matrix influences the measure of voltage between two electrodes. In the case that interest me we have 4 ...
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1answer
97 views

Electrostatics of Conductor

In an isolated conductor the extra positive or negative charges will be distributed on the surface uniformly. Hence there will be no charge inside the conductor, hence no field. But what accounts for ...
4
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1answer
116 views

Flashing a fluorescent light bulb with high voltage

My son and I built a Wimshurst machine (our second try) over the last couple of weekends. It works -- not terribly well, as it only makes 2cm sparks with 20 cm disks (something like 60 kVolt when it ...
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2answers
63 views

Is electric potential a form of potential energy?

As I understand it, the concept of potential energy arises from analytical mechanics. Yet I often see the concept of electric potential $\phi$ introduced without mention of analytical mechanics. For ...
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1answer
30 views

Modelling ions hitting a grid

I want to model the capture of ions by a negatively charged grid made of some proton conductor material like graphene oxide. Are ions captured as soon as they cross the surface, or do they have some ...
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1answer
84 views

Gauss' Law - Parallel plates [closed]

A parallel plate capacitor with dielectric (as above), together with its dimensions. Its plates are square. The capacitance is given by the usual formula, $C = \frac{\epsilon _0 \epsilon _r ...
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6answers
1k views

Paradox with Gauss' law when space is uniformly charged everywhere

Consider that space is uniformly charged everywhere, i.e., filled with a uniform charge distribution, $\rho$, everywhere. By symmetry, the electric field is zero everywhere. (If I take any point in ...
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2answers
45 views

Charging a spherical capacitance

How could one charge a spherical capacitor with a battery or any other emf source?
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2answers
176 views

Energy Stored in a Capacitor with and without Dielectric

I have seen the equation $V = \frac {V_0}{K}$, but also the equation $V=\frac{1}{2}CV^2$. The values of C and V increase in the same linear ration with K (because $C=KC_0$). However, as the energy ...
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1answer
29 views

Ability to discharge static electricity

Ever since I was a child, I have been able to "discharge" static electricity in clothing by touching it. The static falls out immediately! As a child my mother would have me touch all the laundry ...
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1answer
38 views

If we rub glass particles with paper , will there be any charge induction in glass particles?

If we rub glass particles with paper , will there be any charge induction in glass particles ? I know if you rub with silk they do get charged, but i want to know specifically for glass and paper.
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0answers
8 views

how to completely remove the charge from the glass bubble particles?

Do you have any idea on how to completely remove the charge from the glass bubble particles (25-32 micrometer diameter)? Thanks
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1answer
66 views

Are the mass and charge important for the path of a charged particle in an electric potential?

I recently suspected a bug in a subroutine which traces the path of an electron in an electrostatic potential. (I had written that subroutine myself some time ago...) It had separate code-branches for ...
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1answer
88 views

Deriving Voltage from Electric Field

I'm trying to derive the point charge equation for voltage by integrating the point charge equation for an electric field over distance ($dr$) traversed:$ \int (KQ/r^2)\cdot dr$ This is my ...
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1answer
6k views

Direction of Potential Gradient & Electric field

Potential gradient is the negative of the electric field. Does the negative (here) means that its direction is opposite to electric field? If it does mean this, How is the direction of the potential ...
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0answers
26 views

Same-time dielectric breakdown for a coaxial cable with two dielectrics

Suppose we have a very long coaxial cable filled with two concentric dielectrics, with permittivities $\epsilon_{r1}$ and $\epsilon_{r2}$ respectively. Inner (positive) cable electrode has radius $a$, ...
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2answers
200 views

Physical representation of magnetic vector potential

In electrostatics, for scalar potential $V$, we can represent the equipotential surface as a perpendicular surface of the direction of derivative. such as $$ {\bf E}~=~-\nabla V \tag{1} $$ & the ...
2
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0answers
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What is “above” and what is “below” the surface of a sphere?

When studying Electromagnetism using D.J. Griffith's Introduction to Electrodynamics, the boundary conditions for the electric potential across a surface charge density are expressed using the normal ...
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1answer
33 views

Capacitance per unit charge of three long rods, two of which are connected

Suppose we have three very long rods, each with diameter $a$, placed so that their "centers" form an equilateral triangle, with sided of length $d$. Two of the wires are connected with a thin wire ( ...
2
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4answers
2k views

The discontinuity of Electric Field

''electric field always undergoes a discontinuity when you cross a surface charge $\sigma$'' GRIFFITHS In the derivation; Suppose we draw a wafer-thin Gaussian Pillbox, extendind just barely over the ...
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0answers
40 views

Capacitance per unit length of a system containing uniformly charged rod and and infinite charged plate

Suppose we have an infinite plane, and a uniformly charged rod of radius $a$ and linear charge density $\alpha$, parallel to the plane and at distance $d$ from it. Net charge of the plane is $0$. Rod ...
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1answer
120 views

Density of charge induced on a hollow sphere due to eccentric charge inside

Suppose we have a lone hollow metal sphere with net charge equal to $0$. If we were to put a point charge $Q$ inside of the sphere and move it, let's say, away from the sphere center at some distance ...
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1answer
32 views

Electric field of a cross-like conductor

Suppose we have two thin, very long, perpendicular wires soldered to each other so they form a cross. What would electric field lines look like in the plane that wires form, and would it be possible ...