Dipole Definition and 796 Threads

My understanding is that the uniform electric field ##\vec E## cannot be the net electric field since the dipole creates its own electric field as shown in first diagram below, which must superimpose with the uniform electric field. So, yes, the uniform electric field ##\vec E## around the...

Consider a single atom (or particle) in a vacuum (without electric, magnetic or gravitational field) at near zero kelvin (i.e., no photons or particles striking it). I am curious if it will still have a magnetic dipole? If there still is (which I believe), had this been shown experimentally?

Is there anyone out there who can help a newbie understand how to deal with Berry phase dipole moment data? I ran a simulation to calculate dipole moments over time using the Berry phase method. The problem is that there are jumps in my data. There is an example at the end of this post (part...

Hello! Are there any experimental measurements or theoretical calculations of the electric dipole moment of any Rydberg state for CaF or BaF? Thank you!

I have figured out how the force is towards left in the first case. I think it is due to the larger force on - charge. Please help me out with the second and third case.

hi every one what is the amount of orbital magnetic dipole moment of proton? this different with the intrinsic magnetic.

Although problem says sketch, what I really want is the formulae by θ for the radiation. After trying this for a while I cheated and looked at the solution. I still can't figure out the steps on how to get to the solution. the answer is: What I tried: I'll assume that the intensity from a...

I know how to derive field using ##E = -\nabla V## in polar coordinates and doing so gave me $$E = (kP/r^3)(1 + 3cos^3\theta)^{1/2}$$ now I am trying to derive ##E## at point P using the fields produced by +ve and -ve charge respectively and taking components of each along the radial direction...

Hello! I read that if we have a 2 level system (say an atom) and we make it interact with a laser whose frequency is detuned from the resonant transition frequency of the system, the atom experiences an effective potential/force. In the classical description it makes sense, but quantum...

I could do the first part of the question with ease but second part I am not sure how to proceed. Should we calculate the magnetic field at d(where the loop is) and infer something from that for it's motion?? Plz help me out Thanks in advance

On the first attached page ##\mu_z## is associated with orbital angular momentum (Eq. 41.34). On the following pages (Eq. 41.38) it is associated with spin angular momentum? Are these both part of the same thing? I tried to read further but the book does not address this. In example 41.6 it...

I think the answe should be C as shown in the attachment.

Hi there, I approached this problem by making use of the fact that a dipole can be modeled as a small current loop with the magnetic field ##\vec B_1 = \mu_0 \frac {m_1}{4\pi r^2} (2\cos \theta \hat r + \sin \theta \hat \theta)## which is the far-field approximation for a regular circular...

Solution as stated in the problem description.

I have a lot of questions about this single concept. You don't have to answer the questions in the order that I ask, if it is convenient to answer them in a different order. 1. When the dipole moment ##\vec{p}## is in the same direction as the electric field (uniform) it has the least potential...

Hi all. I am trying to do MATLAB simulations for generation of SINE Dipole using two hydrophones spaced distance 'd' apart for signal coming from direction 'DOA'. The MATLAB code is given below. The confusion is that there is constant phase difference of 90 degree b/w SINE Dipole generated using...

Recently I have encountered the following expression for the potential energy of a magnetic dipole of moment ##\boldsymbol{\mu}## placed in an external magnetostatic field B: $$U=-\boldsymbol{\mu} \cdot \textbf{B}$$. However, I was told that magnetic fields are non-conservative, so we can't...

I have to estimate the electric dipole moment of an NV center in units of Am. I know that for a regular electric dipole moment it can be estimated using p=ed. With e=1.6*10^-19 and d=0.1 nm (interatomic distance), this however is in units Cm. I don't know how to go to Am

So I'm mainly having trouble with part b as I have successfully completed part a. In part b I get an answer of 6.3 x 10 ^8 Amperes which my homework tool flags as incorrect. I'm clueless as to where to go from there or why my approach is wrong?

I'm considering the arrangement shown below. Let the positive charge be ##q##, and the negative be ##-q##. To derive the potential energy of this configuration, one usually adds the potential energies of both of the charges in the external field, taking the zero volts equipotential of the...

Hello, I would like to find a mathematical demonstration of this problem. While I have always used it, I could never prove it. Given a charge or current distribution with axial symmetry the electric and magnetic dipole moment are null: (electric dipole moment) (magnetic dipole moment)and...

I've attached a .txt file of my script for those who want to take a look at it Here's a picture of my vector field at time t = 0 I'm very concerned about this picture because from my understanding the Poynting vector is supposed to point outwards and not loop back around, this looks nothing...

Given here is that by geometry r1^2 =r^2 +a^2 - 2ar*cos(theta) But if we try to do vector addition then since direction of dipole is upwards then it should be r^2 =r1^2 +a^2 + 2ar1*cos(alpha) Where alpha is the angle between a and r1. I Don,'t understand how they get it by geometry

The equation that we saw in class is for a continuous charge distribution, I think that for this exercise I need to treat the system as a discrete charge distribution but I'm not sure. Also, I don't know how I can calculate the intensity of the electric field needed to move this charge.

So I was wondering how it is possible that there will be no p-pol light reflected when the refracted light is at 90 degrees to the reflected light (so incoming light is at Brewster's angle). The Brewster's angle was explained to me by saying that the electrons in the medium radiate light...

Can I sum up the potential due to all positive line charges and all negative line charges separately, with the boundary condition being at the edge of my unit cell, the potential should be the same and inside the metal there is a contant potential?

This is a problem from a textbook, and I can't solve it. I know that the equation of Potential energy of electric dipole. Since the configuration is a little bit complicated. I'm confused applying which electric fields.

Hello to everyone. The question or debate here is how you obtain the commonly known equation of dipole electric moment: from the electrostatic potential equation for a multipole of order n: I understand it is related with Dirac delta functions but a step by step solution might be helpful.Thank...

In a recent test we were asked to calculate the electric field outside a concentric spherical metal shell, in which a point dipole of magnitude p was placed in the center. Given values are the outer radius of the shell, R, The thickness of the shell, ##\Delta R## and the magnitude of the dipole...

Would this also be correct? Or is there something wrong with it? I appreciate all your responses! Snarlie

Summary: Why is the electric dipole moment of the nucleus of an atom equal zero? Summary: Why is the electric dipole moment of the nucleus of an atom equal zero? I read about the hyperfine interactions that cause the altering of the energy levels of the nuclues of an atom. Under the...

For reference, this is from Griffiths, introduction to quantum mechanics electrodynamics, p253-255 When deriving the ideal magnetic dipole field strength, if we put the moment m at origin and make it parallel to the z-axis, the book went from the vector potential A $$ A=...

I am reading a PHD thesis online "A controlled quantum system of individual neutral atom" by Stefan Kuhr. In it on pg46, he has a Hamiltonian I am also reading a book by L. Allen "optical resonance and two level atoms" in it on page 34 he starts with a Hamiltonian where the perturbation is...

Given $$\vec E = -\nabla \phi$$ there $$\vec d \rightarrow 0, \phi(\vec r) = \frac {\vec p \cdot \vec r} {r^3}$$ and ##\vec p## is the dipole moment defined as $$\vec p = q\vec d$$ It's quite trivial to show that ##\nabla \times \vec E = \nabla \times (-\nabla \phi) = 0##. However, I want to...

Recently I am learning about electrodynamic radiation and its various types, and it occur to me that since the form of the magnetic field created by the dipole radiation is some combination of cos(wt), 1/r, and cos(kr) (take the approximation of r >> c/w) Therefore, if there is a metal placed...

An electric dipole is a system of two opposite point charges when their separation goes to zero and their charge goes to infinity in a way that the product of the charge and the separation remains finite. Now how can we have a continuous electric dipole volume distribution from such a...

The dipole potential is given by: ##\displaystyle\psi=\int_{V'} \dfrac{\rho}{|\mathbf{r}-\mathbf{r'}|} dV' +\oint_{S'} \dfrac{\sigma}{|\mathbf{r}-\mathbf{r'}|} dS'## I need to prove that ##\psi## is differentiable at points except at boundary ##S'## (where it is discontinuous) I know if...

What is the convention? Because the field lines leave the positive charges and enter the negative ones, do not they?

at a point they become plain waves, how much will they be attenuated when 'received' by a spiral log periodic antenna Vs another dipole? Would an H field created by a loop antenna have less attenuation?

Homework Statement [/B] a) (a) Assuming the HCl molecule consists of point-like ions (H+ and Cl) separated by 1.0 * 10^-10m, find the dipole moment of the molecule. b) Calculate the magnitude and direction of the torque exerted on this dipole if the molecule is subjected to an external electric...

Homework Statement For a configuration of charges and currents confined within a volume ##V##, show that $$\int_V \mathbf J d \tau = \frac {d \mathbf p}{dt}$$ where ##\mathbf p## is the total dipole moment. Homework Equations ... The Attempt at a Solution I have one question: since the...

Consider an electric dipole consisting of charges ##q## and ##-q##, both of mass ##m##, separated by a distance ##d##. If the dipole is given an acceleration ##a## perpendicular to its moment the total electric force on it, due to each charge acting on the other, is given approximately by...

How to prove the dipole moment of an isolated quantum system in isotropic space is identically equal to zero, unless there exists an accidental degeneracy. Thanks in advance

Homework Statement A dipole ##\textbf{p}=p\mathbf{\hat{z}}## (oriented along the z axis for example) is parallel to a conducting grounded plane (xz plane) and is placed at a distance ##d## from it. I have to find the interaction energy and the force between the dipole and the plane. Homework...

Homework Statement Show that the magnitude of the net force exerted on one dipole by the other dipole is given approximately by:$$F_{net}≈\frac {6q^2s^2k} {r^4}$$ for ##r\gg s##, where r is the distance from one dipole to the other dipole, s is the distance across one dipole. (Both dipoles are...

A bar magnet will have a definite magnetic dipole moment, irrespective of the presence of an external field. Why is the moment, then, always defined in relation to the torque it would feel in an external field? Is there any other definition for the same?

Homework Statement A dipole is located at the origin, and is composed of charged particles with charge +e and -e, separated by a distance 2x10-10m along the x-axis. Calculate the magnitude of the electric field due to the dipole at location ##\langle 0.2\times 10^{-8}, 0, 0\rangle##m Homework...

Consider a multi-electron atom. (In our course we deal with alkalis mostly so that we have energy levels which are similar to the hydrogenic ones with quantum defect. I don't know if that is relevant here) Edit: l = orbital angular momentum of a single electron, L = total orbital angular...

Dear all, I am aware that a weakly driven dipole can be modeled as a damped driven simple harmonic oscillator. If I have to model the dipole as being driven by a classical monochromatic electromagnetic wave, would the corresponding simple harmonic oscillator then be in coherent state ? In...