Questions tagged [coulombs-law]

A fundamental and empirical law quantifying the electrostatic force between two charges.

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Is my vector notation in electrostatics correct? [closed]

Let’s say we are expressing Coulomb’s law in Cartesian coordinates (not radial). Let the two charges of equal magnitude (and opposite sign) lie on x-axis. The equation for calculating the force acting ...
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Electric field experienced by a charge

We have two charges, say $Q_1$ and $Q_2$. The magnitude of the electric field $E$ experienced by charge $Q_2$ is: $$E = \frac{k Q_1}{r^2}$$ where $k$ is Coulomb's constant and $r$ is the distance ...
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Lagrange Multiplier as chemical potential in Lagrangian Density

Within Matsubara formalism, we often add one chemical potential term to our Lagrangian density: $\mu\phi^\dagger\phi$, claiming that the chemical potential $\mu$ is one Lagrange multiplier. But at ...
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What will happen if we keep bringing two protons closer and closer to each other, starting from a large distance?

I am asking this question for theoretical understanding of the topic: What will happen if we keep bringing two protons closer and closer to each other, starting from a large distance? I understand ...
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Why did we choose Coulomb's constant $k$ as $9\cdot10^9 \rm Nm^2/C^2$ while define unit of charge instead of any other number?

I understand that while defining charge, Coulomb had to choose any arbitrary value of $k$ to describe unit of charge. But, why did we chose $9\cdot10^9 \rm Nm^2/C^2$ as the value of $k$, but not any ...
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Electrical Force on 2 Line Charges [closed]

Two line segments of length L are located in the x-y plane. One is on the x-axis between -L/2 and L/2. The second is parallel to the x-axis at y=L and again is between -L/2 and L/2. Each carries a ...
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Why electric potential can be evaluated by conservative electric field?

The definition of electric field is following: The electric field is defined at each point in space as the force per unit charge that would be experienced by a vanishingly small positive test charge ...
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Attractive or repulsive force between two statically charges plates [duplicate]

So I'm trying to calculate some mechanics for an electrostatic attraction/repulsion system and I want to make sure that I'm using the correct numbers. I did a bunch of research on my own and I think I ...
1 vote
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Calculating electric field produced by spherical shell [closed]

I'm having trouble solving this problem. Find the electric field a distance $z$ from the center of a spherical surface of radius $R$ that carries a uniform charge density $\sigma$. In here, $R>z$. ...
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Potentials of two near conductors

When two conductors (let's say spherical) of charges $q_1$ and $q_2$ and radii $r_1,r_2$ respectively are brought and connected by a metal rod,we know that flow of charge occurs unless potentials are ...
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A question about Coulomb's law for one moving and one stationary charge

let one charge is moving and another charge is stationary (compulsory). Then the electric force between them can be calculated by coulomb's law?
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Definition of Coulomb's law

In the article about Coulomb's law There is following sentence: Coulomb's law is an experimental law of physics that calculates the amount of force between two electrically charged particles at rest. ...
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Limitation of Coulomb's law

The Coulomb's law is an expertimental law which calcuates the electrostatic force between distinct two electrically charged point particles (point charge) at rest. And Point particle doesn't take up ...
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Why do gravity and electricity sometimes obey inverse square laws over the same distance scale?

Is this a chance mathematical coincidence or is there a good physical explanation for it?
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Validity of coulombs law for a charge in motion [duplicate]

If there is a charge $Q$ kept firmly at rest and another charge $q$ is brought in the vicinity of $q$,it's obvious that $q$ will accelerate towards $Q$. Now,when we say that coulombs law is not ...
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1 vote
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Electromagnetic influences in electric field

Let us imagine a charge $q$ in space. At each point in space,there is an electric field vector associated with it. Now we start moving the charge in a direction. We know that electromagnetic ...
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Dipole formation in electrostatic induction

Let's bring a positively charged rod near a conductor. Now since some electrons in outer shells are not strongly bound to atoms,they will get to the side near the rod. But why does it mean that dipole ...
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1 vote
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Charge distribution on an infinitesimally thin, elliptical conducting thread

Assume an elliptical conducting thread, which is positively charged. Although the thread is considered to be very thin, its stiffness is great enough in order not to allow the Coulomb's forces between ...
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Static condition of surface charges

We know that when charge is supplied to a conductor,they rearrange themselves on the surface thus making a static equilibrium condition. Let's suppose we have $+2e$ charge on a plane sheet conductor. ...
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My textbook, which was written before 2019, says: $k$ [Coulomb's constant] is defined in terms of $c$ to be precisely $k=(10^{-7}\ {\rm N\cdot s^2/C^2)}c^2$ \$\implies\displaystyle\frac{1}{4\pi\...