Dipole moment is the electrostatic moment generated by two opposite charges taken together, far away from the charge's locations

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Potential Energy for dipole in Electric Field

Potential Energy is the work done by the external agent in turning the angle of the dipole from the U=0 position to another position against the influence of the electric field applied right? So if ...
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Is my definition of a dipole and its dipole moment correct?

Assume that we have a dipole affected only by an applied magnetic field where only 2 possible orientations for its dipole moment are possible: "up" and down". A dipole is simply an object with a ...
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What does it mean physically to set $\exp(ikr)=1$ in the dipole approximation?

In the dipole approximation one sets the $exp(ikr)=1+ik.r+...=1$. ($|<f|exp(ikr)\epsilon.r|i>|^2$). Which makes $k.r=0$. What does it mean physically? Is the plane transverse wave converted to ...
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Dipole moment of a single point charge

Kindly refer to the Multipole Expansion section (chapter 3) of David Griffith's Introduction to Electrodynamics. Let us first discuss about why multipole expansion is needed. As far as I understand, ...
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How to compute the magnetic force between two electromagnets?

I wanna compute the magnetic forces between two solenoids with iron cores, is there any analytic formula for this? I guess that dipole-dipole interaction in the link ...
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Water dipole by symmetry argument [closed]

I'm a mathematician and I'm studying Group and Representation theory and I came across with an interesting exercise involving physics, although I don't know physics, since I'm a mathematician, I found ...
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137 views

How does the electrons' magnetic dipole moment get influenced when electrons are moving through a magnetic field?

How does the electrons' magnetic dipole moment get influenced when electrons are moving through a magnetic field? How does the electrons' intrinsic spin influence the direction of the electrons' ...
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61 views

Force on an electric dipole moving through a magnetic field

A dipole of moment $\vec{p}$ where p is fixed, moves with velocity $\vec{v}$ though a magnetic field $\vec{B}$. Show that the force on the dipole is ...
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Method of image charges (semisphere on a metal) (2)

This is a continuation from Method of image charges (semisphere on a metal) . nbubis helped me a great deal concerning this problem and in this post I want to address my problem with the computation ...
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25 views

Whats is the relationship between energy of an atom and its magnetic moment?

I'm working on a problem that says that If $\varepsilon_{\pm}=\mp (\mu \mu_0 H + k \theta \frac{M}{\mu N} )$ is the energy of the atom of a specimen that can orient itself either parallel or ...
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88 views

Spin $1$ vs. spin $1/2$

A crystal contains $N$ atoms which possess spin $1$ and magnetic moment $\mu$. Placed in a uniform magnetic field $B$ the atoms can orient themselves in three directions: parallel, perpendicular, ...
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Figuring out the orientation of a dipole and its distance from a point charge

The problem assigned is this: A dipole is centered at the origin of a coordinate system, and a small charged sphere is some distance away along the perpendicular bisector of the dipole. The particle ...
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strength of each dipole charge

If I have a two dimensional dipole whose line charges are located on the y axis, I know that the electric flux through a gaussian pill box containing both the charges will be zero, that is ...
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Effect of removing material on Magnetization

I realized recently I have some confusion over $\bf{H}$,$\bf{M}$, and $\bf{B}$. Consider some infinite thin plane with permeability $\mu$, and say I know everything else there is to know about it. ...
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1answer
40 views

Understanding of dipole moment and its vector property

I have a trouble understanding the electric dipole moment. The electric dipole moment formula is $${\bf p}= \int {\bf r}' \rho({\bf r}')d\tau '$$ I'm interested in the coordinate, the origin of which ...
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54 views

Dipole moment of a system with net charge

I want to calculate the dipole moment of an object that is not neutral. I know for neutral charges the dipole moment has a rather simple form: $$d = \sum q \cdot z$$ But suppose I have a charge of ...
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47 views

How does this approximation of the $B$-field of a charged rotating disk for $z\gg R$ make sense?

Consider a disk of radius $R$ rotating with angular velocity $\omega$ and with a surface charge density $\sigma$. I have shown that the magnetic field as a function of the distance along its axis (z) ...
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1answer
67 views

What is the complex dipole moment?

I have some problems with getting the complex (time dependent) dipole moments of some dipoles in a configuration. I eventually want to get the electric and magnetic fields of the configuration, but my ...
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27 views

Quadratic versus linear Stark shift

I'm trying to understand why the Stark shift changes from quadratic to linear as the applied electric field increases. I think there is some kind of connection to whether the induced dipole moment is ...
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225 views

Physical meaning of electric dipole moment [closed]

I am reading about the electric dipole moment. What I can't understand, and seems that no one cares to explain, is what is the physical meaning of it. To my understanding everytime that dipoles are ...
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43 views

Oscillator Strength vs. Dipole Moment

I'm reading "Bose-Einstein Condensation in Dilute Gases" and, in the background chapter (on page 51), the authors introduce the idea of the oscillator strength for a particular transition. The ...
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450 views

Classical proof of the gyromagnetic ratio $g=2$

I was reading Representing Electrons: A Biographical Approach to Theoretical Entities, by Theodore Arabatzis. At a certain point, where he is explaining the history of the magnetic moment of the ...
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48 views

Electric field of a dipole in cartesian

I have the function that describes the electric field of a dipole in cartesian coordinates: $$E_z= \frac{p}{4\pi\epsilon_0} \cdot \left(\frac{3z^2}{r^5}- \frac{1}{r^3}\right) $$ and ...
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49 views

Force on an electric or magnetic dipole

The formulae for the force on an electric dipole and the force on a magnetic dipole seem to be closely related: $$\mathbf{F}_{e} = (\mathbf{p} \cdot \mathbf{\nabla}) \mathbf{E}, $$ $$ \mathbf{F}_{m} ...
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59 views

Induced dipole in a molecule with a permanent dipole moment?

How can there be an induced dipole in a substance with a permanent dipole moment? I thought an induced dipole can occur only in a non-polar substance. Yet, this is part of the proposed dipole-induced ...
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29 views

Dipole moment of a displaced charge distribution [duplicate]

This one is part b) of the problem I asked a day ago. Special thanks to MarkMitchison and sbp on the first part. I finally got it. (How can I prove that the dipole moment is zero?). Alright, back to ...
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How can I prove that the dipole moment is zero? [duplicate]

I'm playing around with this one problem in my workbook. "There's a radially symmetric charge distribution centered at the origin. What's the dipole moment of that charge density?" It took me a ...
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112 views

Radially symmetric charge distribution (dipole moment) [closed]

a) There's a radially symmetric charge density $\rho(r)$ centered around the origin. Determine the dipolemoment of that charge density. b) Let $\rho(r)$ be an arbitrary charge density now. ...
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Dipole Moment (spherical/arbitrary charge density) [duplicate]

I'm new here. I got to this website while searching for links to fill my gaps on some topics. I have found some amazing posts for many different topics. Just amazing. Anyway, I'm currently dealing ...
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229 views

torque in electric dipole placed in nonuniform electric field

In the uniform electric field case, we can know the rotational axis is at the position in the middle of positive charge and negative charge. However, if the electric field is non-uniform, or simply ...
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97 views

Do Dipole Moments Obey Superposition?

Essentially, I have two surfaces which I know how to find the dipole moments for. I realize that $V_{dip}(r) = \frac{1}{4\pi \epsilon_0 r^2} \mathbf{\hat{r}} \cdot \int \mathbf{r'} ...
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49 views

Induced dipole moment of an atom

Assume that we have a neutral atom that consists of a $+Q$ particle in its center surrounded by a uniform charge density $\rho$ such that $-Q = (4/3)\pi R^3 \rho$, where $R$ is the radius of the atom. ...
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215 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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Electric field due to an electric dipole at a point on the equatorial line

According to [tamilnadu][1] textbook Electric field due to an electric dipole at a point on the equatorial line is given as The direction of E is along ...
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72 views

As the magnetic field propagates does it have a momentum that can be felt by another magnetic field of the same charge?

If I have a solenoid and a permanent magnet, and I placed the magnet an inch away from the solenoid, oriented in a position where the magnet would be repelled as the solenoid is turned on. Is it a ...
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353 views

difference between magnetic dipole moment and torque on a magnetic dipole?

I am a bit confused. What is the difference between magnetic dipole moment and torque on a magnetic dipole ?
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275 views

Find out gradient of electric potential at ${\bf r}$ created by eletric dipole of moment ${\bf p}$ [closed]

Suposing an electric dipole of moment ${\bf p}$ located at the origin which creates an electric potential at ${\bf r}$ given by ...
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1answer
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Force on a dipole

The force exerted by an electric field on a dipole is : $$(\vec{p}.\vec{\nabla})\vec{E}$$ but how exactly do I develop this ? Is it : $$p_x\frac{\partial E}{\partial x}\vec{e_x} + ...
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Why does the electric dipole moment of the electron tell us about its sphericity? [duplicate]

There are a bunch of experiments that claim to show that the electron is highly spherical by measuring the electron electric dipole moment. See e.g.: ...
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147 views

Dipole moment of a specific charge distribution

A negative charge cloud distribute as a ellipsoid and a positive point charge situated at the centre of the ellipsoid.What should be the dipole moment of charge distribution.I mean, if the negative ...
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1answer
240 views

How could the effective electric dipole interaction be derived

In some papers (e.g. Bernreuther equation (1.4), The electric dipole moment of the electron) you can find the electric dipole interaction defined as $$L_I=-\frac i2 ...
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570 views

What exactly is electric dipole moment & how it works?? and Why Electric Dipole Moment vector's direction is from negative charge to positive charge?

What exactly is electric dipole moment & how it works/used? (don't go into deep mathematical calculations) Please answer the question about the direction with good details. Don't just say that ...
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1answer
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Force between two point dipoles

What would the force between two parallel point dipoles be? I was thinking of doing it the way force between two point charges is found out, by finding the field and then the force but I am not able ...
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1answer
198 views

How does An Electric Field Create a Dipole Moment of a Rydberg Atom?

I know that an Rydberg Atom will not usually have a Dipole Moment - as the positive nucleus are surrounded by a negative electron cloud, so there is no uneven charge distribution. However, I also ...
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What does it mean to say “a paramagnetic material is attracted to an external magnetic field?”

I'm just having a hard time wrapping my head around what actually goes on when a paramagnetic material is exposed to an external magnetic field. I understand that the individual dipoles line up so ...
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2answers
152 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 ...
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Divergence in interaction between induced dipoles

Suppose I have two polarizable point-particles 1 and 2 arranged on the z-axis and separated by $r$. Each particle has a dipole moment $\mathbf{p}_i=\alpha \mathbf{E}_i$. If we apply an external field ...
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What is $\delta$ in this formula?

What is $\delta$ in the formula below? How can it be evaluated? Is $P$ the expectation value of $cos\theta$? Source (Influence of Hydrophilic Surface Specificity on the Structural Properties of ...
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Potential energy of a dipole in a uniform electric field convention?

When finding the potential energy of a dipole in a uniform electric field, I was told by my lecturer that the convention is that the potential energy is 0 when the dipole moment and electric field ...
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Electric dipole moment(EDM) underlying physics [duplicate]

I read in a physics today paper, The electron can have nonvanishing EDM only if nature violates symmetry under time reversal (T) and under the combined operations of charge conjugation (C), which ...