Electric dipole Definition and 157 Threads

Homework Statement Find the frequency of oscillation of an electric dipole, of dipole moment p and rotational inertia I, for small amplitudes of oscillation about its equilibrium position in a uniform electric field of magnitude E. Answer: [(pE/I)^0.5]/(2*pi) Homework Equations I...

Homework Statement An electric dipole in a uniform horizontal electric field is displaced slightly from its equilibrium position, where theta is small. The separation of the charges is 2a, and each of the two particles has mass m. Assuming the dipole is released from this position, show that...

I understand that potential energy of an electric dipole is U(θ)=-pEcosθ where p is the dipole moment, E is the electric field and θ is the angle between vector p vector E. However i have some doubts about its derivation. in my readings, the work done is derived as such: dw=t*d(theta) =...

Hi,can anyone tell me how to calculute magnitude and direction of the electric dipole moment of a system? If the system is a bit complicated? What kind of formula I suppose to use? \vec{p}=q\vec{d}?

Homework Statement Three metal balls with unequal radii R1 < R2 < R3 are placed at the vertices of an equilateral triangle, whose sides have length a. The balls are connected by thin metal wires. A positively charged rod is brought into contact with one of the balls and transfers an amount of...

Suppose there is an electic dipole that starts to oscillate with frequency ω at t=0, then how long does it take the electric dipole to emit a photon? We know that the radiant power of such electric dipole calculated from quantum physics is P\left( \omega \right) = \frac{{{\omega ^4}}}{{3\pi...

Electric Dipole Electric Field.. URGENT Homework Statement For the electric dipole shown in the figure, express the magnitude of the resulting electric field as a function of the perpendicular distance x from the center of the dipole axis in terms of the electric dipole moment, p. Homework...

Homework Statement Show that E = \frac {q}{4\pi\varepsilon(z-\frac{1}{2}d)^2} - \frac{q}{4\pi\varepsilon(z+\frac{1}{2}d)^2} is E = \frac {q}{4\pi\varepsilon z^2} [(1-\frac{d}{2z})^{-2} - (1+\frac{d}{2z})^{-2}] Homework Equations The Attempt at a Solution After...

I have an electrodynamics question stemming from a recent episode of the game show "1 vs 100" in which I disagreed with the show's answer. The question is: "You touch your grandma's elbow and feel a spark. What do you have an excess build-up of, besides shame?" Answer choices were...

When using k.p theory to calculate the magnitude of the electric dipole moment in semiconductors for band-to-band transitions, the value of the dipole moment is basically fitted to the effective mass of the electron in the conduction band. However, the values turn out to be larger than the...

Homework Statement An electric dipole (something that has charge +q on one end and charge -q on the other end separated by a distance 2a) is in a uniform horizontal electric field of magnitude E. Initially the electric dipole is aligned horizontally until it is displaced slightly by an angle...

Dear all I have done some studies trying to understand the relation between the QCD theta angle and neutron electric dipole moment. General, the QCD vacuum produces the term L_{\theta} = \theta g_s^2\: G_a^{\mu\nu} \, G^a_{\mu\nu} this I can derive! I have studied Srednicki ch 93, Ramond...

potential due to electric dipole is V = p.r / 4(pi)(epsilon)r3 show the tangential component of the electrical field is = psin(theta) / 4(pi)(epsilon)r3what I've tried: i assumed there are 2 charges separated by distance r potential difference U = qV = -qE.r so can i say...

This page contains one derivation for the potential energy: http://www.shef.ac.uk/physics/teaching/phy205/lecture_4.htm" Result: U=-pEcos\theta where E = magnetic field's magnitude P = dipole moment = d*Q d= distance between + and - charge Q= charges' magnitude \theta = angle between the...

Hello The electric dipole potential is V (\textbf{r}) = \frac{1}{4\pi\epsilon_o} \frac{\textbf{p}\bullet \hat{r} }{r^2} I am trying to figure out the algebra in my book. How do you evaluate the scalar product of the dipole moment and the unit vector in the above equation? I get qd...

Hey have another problem with one of my exercises Homework Statement Make a crude estimate for the mean life of an electric dipole transition in a atom E_\gamma = 10 eV in a nucleus E_\gamma = 1 MeV Homework Equations W_{\alpha \beta} &=& \frac{4}{3} \frac{e^2}{\hbar^4 c^3}...

Homework Statement The electric dipole moment of a CuSO4 molecule is 3.2 * 10^-32 (i.e. 10 raised to the power of -32)C-m. Find the separation between the copper and sulphate ions. Homework Equations Electric deipole moment = 2aq where 2a=separation between the two charges q and -q...

Homework Statement Two dipoles are oriented as shown in the diagram below. Each dipole consists of two charges +q and -q, held apart by a rod of length s, and the center of each dipole is a distance d from location A. If q = 6 nC, s = 1 mm, and d = 6 cm, what is the electric field at location...

I know the definition of the electric dipole moment is given by \mu = -e x, where e is the charge of electron and x is the displacement. I am thinking a mechanics counterpart of the dipole moment. We note that in mechanics, the moment is defined as the force cross the position vector. Consider...

Homework Statement Given an electrical dipole of electrical dipole momentum \vec P = p\hat k, centered in 0\hat i + 0\hat j + 0\hat k, find the potential in all the space, where V(\infty ) = 0. If the dipole is now surrounded by a hollow spherical conductor (initially discharged), find the...

Is the field of an electric dipole conservative? Initially I thought it would be, for no particular reason but that's just what my high school intuition thought. (haha I thought everything would be conservative apart from friction) But I was reading up on some vector calculus and...

Hi I want to calculate the electric dipole moment of point charges along the z-axis with distances a and with the charge distribution \varrho (\vec{x}) = q \delta (\vec{x}) - 2q \delta (\vec{x} - \vec{a}) + q \delta (\vec{x} - 2 \vec{a}) and of course \vec{a} = a \vec{e}_{z} I...

Homework Statement This is a mastering physics question but it does not count for my assessment mark, i am using an alternative approach to the one given in the hints. And off course i got the question wrong but i don't understand why.. "[URL...

I was hoping people might be able to provide some insight into the following fairly basic scenario (not homework/school related). Imagine a positive point charge on the x-axis. Also on the x-axis, to the right, is an electric dipole, with finite spacing, pointed along the x axis, with the...

microwave can be used to engineering potentials for alkali atoms i find that in the literature, people only take the magnetic dipole transition into account why the electric dipole transition is neglected? is it forbidden?

Homework Statement Two point charges likes those in the figure below are called an electric dipole. Show that the electric field at a distant point along the x-axis is given by E_{x}=\frac{4k_{e}qa}{x^3} Figure: http://img300.imageshack.us/my.php?image=58ag9.png Homework Equations...

As per my understanding, the position of most stable equilibrium of a dipole placed in a uniform electric field is when it is aligned with the field, i.e. when E and p (dipole moment) are in the same direction. Also the position of most unstable equilibrium is at the position where the dipole...

Help me to sort out this problem:: Prove that, "integration over[J(r)dr]=del(p)/del(t)" ... where p is the electric dipole moment ... please as soon as possible, reply me ...

Homework Statement Hey everyone, I need to derive what the E and B fields look like for the electric dipole in the near field region close to the source i.e. lambda>>r. Homework Equations The Attempt at a Solution I managed to derive it for the situation far from the source but...

1. In an electric dipole moment, assume that both charges are positive and find the electric field "E" at point "P", assuming X>>d, where "d" is the distance between the two charges and "X" is the distance of point "P" from the center of the dipole. I have thought a lot about it but I am very...

Homework Statement I got this problem from my physics textbook, and I'm not sure how to solve it. A point charge R is distance p from the center of a diple consisting of charges + and - q separated by distance s. The charge R is located in the plane that bisects the dipole. What is...

An electric dipole consists of a pair of point charges each of magnitude 4nC separated by a distance of 6cm. What is the electric field strength at the point midway between the charges? Not sure what equations to use? Any ideas?

Homework Statement Show that a line of charge density \lambda exerts an attractive force on an electric dipole with magnitude F = \frac{2\lambda p}{4\pi\epsilon_{0}r^{2}}. Assume that r is much larger than the charge separation in the dipole. Homework Equations I need to show that the...

Homework Statement I we know the eigenstates of the system be |\psi_1\rangle and |\psi_2\rangle. Current state of the system is |\Psi\rangle = c_1 |\psi_1\rangle + c_2 |\psi_2\rangle Try to find the expectation value of electric dipole moment \mu (assume it is real) and write it in...

Homework Statement An electric dipole moment, vector P, is initially pointing in the directio of a uniform electric field, vector E (say, in the positive x direction). How much external work is needed to turn the dipole by 90 degrees? Homework Equations vector P is directly...

I have a very basic beginners question in physics and was wondering where to post it. The post is going to be: TITLE What is the difference between an electric dipole and a capacitor ? I am a trying to understand the difference between an electric dipole and a capacitor. The wikipedia...

Hi, I am aware that the effects of a dielectric sphere in a uniform electric field have been done in many introductory electromagnetism books. Is anyone ware of a similar problem where the uniform electric field is replaced by a dipole field? Would solving such a problem for the resultant...

[SOLVED] Electric Dipole Homework Statement I have an carbon atom polarized so it is essentially a physical dipole. I know the spacing between the "two charges" and I know what the charges are. I need to determine the potential difference across the polarized atom. Homework Equations...

Homework Statement In a xy-plane, we have a +q charge in A(0,h) and a -q charge in B(0,-h). Let's take a field line passing through A, that has horizontal slope in A. Find the point C(m,0) where this field line intersects the X axis. Homework Equations I think Gauss' law \epsilon_0...

Homework Statement An electric dipole of moment p is placed at a distance r from a point charge +q. The angle between p and r is phi. Show that the energy of interaction between the dipole and the charge is -pqcos(phi)/4\pi\epsilon0r^2 Derive equations for a)a radial force on the dipole b)a...

Homework Statement For \Deltal = 0 the transition rate can be obtained by evaluating the electric dipole matrix elements given by \vec{I} = \int \Psi^{*}_{1,0,0} (e \vec{r}) \Psi_{2,0,0} d\tau Homework Equations The Attempt at a Solution I've got the two wave functions...

Homework Statement A small object with electrc dipole moment \overrightharpoonup{p} is placed in a nonuniform electric field \overrightarrow{E} =E(x)\hat{i}. That is, the field is in the x direction and its magnitude depends on the coordinate x. Let \theta represent the angle between the...

Homework Statement An ammonia molecule (NH_3) has a permanent electric dipole moment 5.0 * 10^-30 Cm . A proton is 2.50 nm from the molecule in the plane that bisects the dipole. What is the electric force of the molecule on the proton? Homework Equations E_dipole = K 2p / r^3 (on axis...

Hi I was wondering if anyone could give me info about atomic electric dipole moment at a very fundamental level (fenomenological, basic quantum), I do not seem to find it when I google =( My Aim is just to understand van der Waals binding in solids a little bit more.

(This question doesn't apply to a specific problem, hence I'm not using the template.) Consider a dipole, approximated as a "dumbbell": two oppositely-charged spheres (charges of equal mag.) connected by a rod (that is, the chemical bond). Suppose that I know the dipole moment. If this dipole...

Homework Statement Since the electrostatic field is conservative, show that it is irrotational for an electric dipole, whose dipole momentum is p .Homework Equations \nabla \times \mathbf{E} = 0 The Attempt at a Solution I know that the components of the electric field in spherical...

Problem Diagram (Ignore the tildes, they're just placeholders): Below: An electric dipole ~~~~~~~y-axis~~~~~~~~~~~~~~~~~~ ~~~~~~~|~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~|~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~|~~~~~~~~~~~~~~~~~~~~~ ~~<---a---> <---a--->~~~~~~~~~~~~~~~ +Q --------- X ---------...

We have an electric dipole. Now, let us draw a Gaussian surface around our electric dipole. Now, the total charge enclosed by our Gaussian surface is zero, so according the Gauss' Law the flux through the Gaussian surface is zero, and so is the electric field intensity due the electric dipole...

Homework Statement Two point charges likes those in the figure below are called an electric dipole. Show that the electric field at a distant point along the x-axis is given by E_{x}=\frac{4k_{e}qa}{x^3} Figure: http://img300.imageshack.us/my.php?image=58ag9.png Homework Equations...

I am having some problem with the formulas for calculating the electric fields of an infinite line of charge and an electric dipole. I don't understand conceptually why they are the way they are. Can someone explain? Any help is appreciated! [Note: K=1/(4*pi*epsilon_o), lambda=linear...