# Dipole moment Definition and 27 Discussions

The electric dipole moment is a measure of the separation of positive and negative electrical charges within a system, that is, a measure of the system's overall polarity. The SI units for electric dipole moment are coulomb-meter (C⋅m); however, a commonly used unit in atomic physics and chemistry is the debye (D).
Theoretically, an electric dipole is defined by the first-order term of the multipole expansion; it consists of two equal and opposite charges that are infinitesimally close together, although real dipoles have separated charge.

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1. ### I Two molecules with different polarizability in an EM field

If I have two separated and non-interacting molecules with different constants polarizabilities ##\alpha_1## and ##\alpha_2## and I send an EM field of frequency ##\omega## first on the molecule no.##1## and then on the molecule no.##2## so that the two molecules will have a dipole moment...
2. ### I Dipole moment of a cylinder of uniform polarization

If I want to calculate the dipole moment of a dielectric cylinder of uniform polarization perpendicular to its axis, I could multiply the polarization by the volume of the cylinder, which is okay. But another method is to consider the cylinder to be a superposition of two cylinders of equal and...
3. ### I Derivative of the retarded vector potential

In a problem of an oscillating electric dipole, under appropriate conditions, one can find, for the potential vector calculated at the point ##\vec{r}##, the expression ##\vec{A}=\hat{k}\frac{\mu_0I_0d}{4\pi}\frac{cos(\omega(t-r/c))}{r}## where: ##\hat{k}## is the direction of the ##z-axis##...
4. ### I Something about retarded potentials for oscillating electric dipole

In a problem of an oscillating electric dipole, under appropriate conditions, one can find, for the potential vector calculated at the point ##\vec{r}##, the expression ##\vec{A}=\hat{k}\frac{\mu_0I_0d}{4\pi}\frac{cos(\omega(t-r/c))}{r}## where: ##\hat{k}## is the direction of the ##z-axis##...
5. ### Why the Stern-Gerlach experiment didn't detect the L?

i recently read about the stern-gerlach experiment and found out that they did it in the first place to verify the principle of the "space quantization " introduced by Bohr , and they thought they did detect the quantization of the orbital angular momentum of ( L = 1 , m = 1,-1 ) neglecting the...
6. ### Electric dipole moment vs electric current dipole moment

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
7. ### Changing the k constant in voltage potential equation?

Summary:: What if you were calculating the voltage potential for a dipole, but underwater? I'm making a predictive model (in R programming) for the voltage potential at any point around a dipole. I need to be able to change parameters, one being the k constant. V=( kpcosѲ)/(r^2). Where V is...
8. ### A Dipole moment of an isolated quantum system

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
9. ### Potential due to a charged plate using the dipole approximation

Homework Statement A plane z=0 is charged with density, changing periodically according to the law: σ = σ° sin(αx) sin (βy) where, σ°, α and β are constants. We have to find the potential of this system of charges. Homework Equations The Attempt at a Solution [/B] I...
10. ### Deriving magnetic dipole moment from multipole expansion

Homework Statement This is from Griffith's Introduction to Electrodynamics, where the book is deriving the magnetic dipole moment from multipole expansion of the vector potential The vector potential of a current loop can be written as \mathbf{A(r)}=\frac{\mu_0 I}{4\pi} \left[ \frac{1}{r}...
11. ### Why do neutron stars have such powerful magnetic fields?

The sources I've looked at claim the magnetic field is present because there are still some electrons in the neutron star. Here is how I understand their reasoning: a star's radius significantly decreases when it collapses into a neutron star, ultimately decreasing its moment of inertia. In...
12. ### Could a distribution of magnetic Dipoles create an Energy minimum

The think is that I would like to create a magnetic trap "minimum of magnetic potential energy in all 3 directions of space" using a distribution of magnetic dipoles as a field generator. In other words, I would like to know if setting in some way some magnetic dipoles is possible to create a...
13. ### I Calculate the Dipole Moment of an object

How would I calculate the Dipole Moment of a piece of mild steel approximately 15cm in length?
14. ### The direction of electric dipole moment of water molecule

I was watching a video explaining how microwave ovens work when I found that there is a difference between my physics textbook and online images of the electric dipole moment of the water molecule, as well as the one shown in the video. Why do they differ?
15. ### Interaction between a neutral atom and an external magnetic field

Lets suppose that I have a magnetic dipole moment at (0,0,0) pointing to the Z axis, and in the position (X,Y,Z) in the space, I have a Hydrogen atom, I would like to know the exact interaction between the magnetic field created by the magnetic dipole moment in (0,0,0) and the magnetic fields of...
16. ### Forces between the dipole and a point charge

Homework Statement We have an electric dipole with moment P=2*[10][/-5] pointing in x direction. What is the force experieced by dipole at origin when a point charge Q=3*[10][/-4] is located at (0.014 m ,0,0) Homework Equations 1. [E][/dipole]=(1/4π[ε][/0])(2p/r3) 2. p=qs 3. F=qE 4. τ=pEsinϑ...
17. ### Dipole moment, electric potential

Homework Statement I am given this picture and I know that |q1|=2nC, |q2|=5nC, d=1mm I need to first find the total dipole moment of the system. Then I need to find an equation that represents the electric potential due to this net dipole moment for all (everywhere) Homework Equations p=qd...
18. ### Force between 2 parallel magnetic dipole moments

Homework Statement Find the force of attraction between 2 magnetic dipoles a distance r apart. Both dipoles point to the right. Homework Equations The Attempt at a Solution All I need help with is figuring out how to determine if the force is attractive or repulsive between the 2 dipole...
19. ### Electric dipoles and a magnetic dipoles

Is there any interaction between a perfect magnetic dipole and a perfect electric dipole, both at rest? What abut real dipoles? What does QED say about this?
20. ### About the Orbital Dipole Moment

I was going through the chapter Chemical Bonding in one of the books and found something about orbital dipole due to lone pairs. In each diagram the orbital dipole due to lone pair was directed from the central atom to the end of the hybridized orbital (lone pair). Why is that so?
21. ### B Dipole moment

What does it mean when we say "centre of charges coincide"? What is the physical meaning of dipole moment?
22. ### Potential Energy for dipole in Electric Field

Homework Statement To derive Potential Energy for dipole p in Electric Field E. 2. Homework Equations 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...
23. ### A Transition dipole moment - polarized absorption

Hi everyone, I am interested how is polarized light absorbed by a molecule or an atom. Unfortunately, I come to a problem in the derivation where a complex vector in a real space appears. This is something I never seen before and I do not know how to interpret it. Therefore I would like to ask...
24. ### Dipole Moment of Mono-nuclear

Do mono-nuclear molecules have dipole moment? If yes then, what type of dipole moment? why do they have (or do not have) dipole moment?
25. ### Mathematical relation between dipole moment and frequency?

how can we relate innermost stable circular orbits, keplerian, epicyclic, frame dragging precession frequency with dipole moment.
26. ### Dipole Moments

Can someone explain how to determine if a compound has a dipole moment and how to determine how big or small it is (possibly numerical value)? I have a final tomorrow and I've looked this up on multiple website and cannot find any good explanation.
27. ### Why does a hydroquinone has a non zero dipole moment?

Why does hydroquinone possesses non zero dipole moment? The OH groups present at para positions on the benzene ring should cancel the effect of each other...if there is a plane change then exactly in which cases molecules do change planes?