Electric dipole Definition and 157 Threads

Homework Statement [/B] ZnS crystalizes in the B3 type structure with the space group is F¯43m. This structure is shown below and can be regarded as the bi-atomic form of the diamond lattice (F d¯3m). Upon applying a force along the [1,1,1] direction, the crystal might experience a change in...

Homework Statement Hi everyone, My problem is fairly simple: We have a circular current loop enclosing area A, and with a constant current I. The loop is rotating about its diameter at a constant angular frequency \omega. All we need to do is find the electric dipole, and magnetic dipole...

Imagine an electric dipole with charges ##+q##, ##-q##, mass ##m## and size ##d##. Assume this dipole is oriented horizontally and is sitting at rest on top of some weighing scales on earth. As the charges are at rest the weight of the dipole is just ##-mg##. But by the principle of...

Homework Statement Text description: Let V(z) be the potential of a ring of charge on the axis of symmetry at distance z from the center. Obtain the first two non-vanishing terms of the multipole expansion for V(z) with z>>a where a is the radius of the ring. Can you see by symmetry that the...

Homework Statement An electric dipole consists of two charges of equal magnitude ##q## and opposite sign, which are kept at a distance ##d## apart. The dipole moment is ##p= qd## . Let us next place two such dipoles, placed at distance ##r## apart, as shown in the accompanying figure. a)...

Homework Statement Suppose a radiating electric dipole lies along the z axis. Let ##I_1## be the intensity of the radiation at a distance of 10 m and an angle of 90 degrees. Find the intensity (in terms of ##I_1##) at (a) a distance of 30 m and an angle of 90 degrees, (b) a distance of 10 m...

Hi there, I am reading Chapter 9 of Jackson Classic Electrodynamics 3rd edition, and I don't see why this equality is true, it says "integrating by parts", but I still don't know... any help? http://imageshack.com/a/img673/9201/4WYcXs.png

Hello there, I want to derive ##U(\theta) ## for electric dipole placed in uniforum electric field $\vec{E} = E\vec{e}_x$ where E is constant. I define the dipole moment as $p = qd$, where $d$ is the distance from the two I write $\mathm{d}W = p\,E\sin\theta \mathrm{d}\theta =...

Homework Statement [problem 3.49 from Griffiths' Introduction to Electrodynamics 4th edition. The relevant equations from the book are reproduced in "relevant equations" below] In Ex. 3.9, we obtained the potential of a spherical shell with surface charge ##\sigma(\theta) = k\cos\theta##. In...

Homework Statement An electric dipole with -q at the clouds of height h, and +q beneath the surface with height -h. Given q=200 C, and h=6000m Electric discharge occurs with electric field of 3000 V/m near ground level, and 200 V/m above the clouds. Find the ranges where discharges are...

Homework Statement An electric dipole consists of a pair of equal but opposite charges, +Q and -Q separated by a distance d. What is the electric potential at the point that's midway between these source charges? Through using the formula electric potential = kQ/r, I found the electric...

The PE of an electric dipole in an external E-field is U=-p.E where p is it's dipole moment. I was under the impression I could find U, and then easily determine the force on the dipole using F=-∇U, to obtain Fx=px∂Ex/∂x+py∂Ey/∂x+pz∂Ez/∂x Fy=px∂Ex/∂y+py∂Ey/∂y+pz∂Ez/∂y...

2 particles of charge q are placed at 2 vertices of an equilateral triangle of side a. An electric dipole is placed at the third vertex with its dipole moment orientated parallel to the opposite side of the triangle. a) Determine the magnitude of the torque on the dipole due to the electric...

i do not know why. does the magnetic moment of an atom come only from the spins of the electrons?

Hello, I have this matrix element \langle n', l', m'| x |n, l, m \rangle where x=rsin\theta cos\phi in spherical polars Which I write explicitly as: =\int \int \int R_{n', l'} R_{n, l} A_{l', m'} A_{l, m} P^{m'}_{l'} P^{m}_{l} e^{im\phi} e^{-im\phi} rsin\theta cos\phi r^{2} sin \theta d...

Homework Statement Consider an electric dipole in the attached document. At point P, the fields E+ due to q+ and E- due to q- are: E+ = kq/(r-a)2, E- = -kq/(r+a)2 Then total field at P is: E = E+ + E- = kq [ 1/(r-a)2 - 1/(r+a)2] y-hat Homework Equations See question 1. The...

the two energy level atom, whose hamiltonian takes the form \hat{H_A}=E_g|g\rangle\langle g|+E_e|e\rangle\langle e|, where E_g as well as E_e represent the eigenvalues and |g\rangle as well as |e\rangle denote the ground state and excited state. There is an interaction between the atom...

Homework Statement There are three charged line segments, each with linear charge density λ, extending from the origin to (a,0,0), from the origin to (0,b,0), and from the origin to (0,0,c). a) Find the dipole moment of this charge distribution. b) Find the first two terms in the...

Homework Statement It's me again.. I solved this question but i want to be sure about it,so what do you think about my solution bellow? a dipole consists of a positive charge q at x=d/2 and a negative charge -q at x=-d/2 (d is the distance between the charges). What is the potential produced...

The problem: You and your engineering crew are in charge of setting up a wireless telephone network for a village in a mountainous region. The transmitting antenna of one station is an electric dipole antenna located atop a mountain 2.00 km above sea level. There is a nearby mountain that is...

Hello all, I am so confused on why a net torque on a dipole in a uniform electric field would not be equal to zero. Wouldn't one end rotate clockwise, the other counterclockwise and cancel out to zero? Thanks.

Electric Dipole as x >> l, how do I simplify this correctly? Homework Statement ELECTRIC DIPOLE : 15.0 POINTS A charge −Q is located at x=−l/2 and a charge +Q is located at x=l/2. Thus the separation between the two charges is l. The total electric field on the x-axis can be written...

Homework Statement Calculate the Electric field of a Dipole from its Potential. \vec E=-\operatorname{grad}(\Phi_D) Homework Equations \Phi_D(\vec R)=\frac{Q}{4\pi\epsilon_0} \cdot \frac{\vec d \vec R}{R^3} The Attempt at a Solution Hi all! I am trying to calculate the electric Field of a...

Homework Statement Point charges +4.70 and -4.70 are separated by distance 3.90mm, forming an electric dipole. The charges are in a uniform electric field whose direction makes an angle 37.0 degrees with the line connecting the charges. What is the magnitude of this field if the torque exerted...

Proton electric dipole moment... what's that all about?

Homework Statement Two electric dipoles, oriented as shown in the figure, are separated by a distance r. What is the force on p1 due to p2 Homework Equations F = (p dot ∇)E The Attempt at a Solution I'm confused on the p dot ∇ part. How is the divergence of p not just...

Homework Statement Consider the following species in the gaseous state: NF_3, \ BeF_2, \ BCl_3, \ KrF_4 \ and \ SeO^{2-}_4 . Which of them have electric dipole moment? Homework Equations The Attempt at a Solution I tried google, but I can't figure out how to check that..

Greetings, I wonder with respect to what coordinates the formulas given for the electric dipole is valid. Also I want to comprehend the difference between pure and physical dipoles and why many books put the origin of the cartesian system they define on the middle point of the electric dipole...

I am trying to understand the elctric dipole approximation when an atom interacts with an electromagnetic wave. I know that if the size of the atom is much much smaller than the wavelength of the radiation, then the dot product od the wavevector and the position vector becomes constant. I...

Hi friends as all know that the direction of electric dipole moment vector is from negative charge towards the positive charge. I am pretty confuse that this direction is allotted to the dipole moment vector with some reason or just by convention.

What is the physical meaning of electri dipole moment? What does it tell us about the dipole? Please don't just throw away mathematical equation (p=qd r_hat); help me to get its physical sense!

Please help me with the attached question. I don't understand how you get from the first line to the second line in (2). (I'm not too familiar with working with cross products and vectors). Also, I don't know how you get (5) from (1) and (2). Any help would be much appreciated. Thanks! :)

Homework Statement How do I show that our equations for the E- and B-fields for the oscillating electric dipole do NOT satisfy Maxwell’s equations? Homework Equations After approximations in retarded potentials, we have our E- and B-field as following: E =...

How do I show that our equations for the E- and B-fields for the oscillating electric dipole do NOT satisfy Maxwell’s equations? After approximations in retarded potentials, we have our E- and B-field as following: E = -ω2μ_{0}p_{0}(4∏r)-1sin(θ)cos[ω(t-\frac{r}{c})]\hat{θ} (Griffiths...

Homework Statement An electric dipole is situated at the origin and points along z. An electric charge is released from rest at a point in the (x,y) plane. Show that it swings back and forth in a semicircular arc about the origin. Homework Equations Electric field of a dipole (coord...

Homework Statement The prototypical electric dipole is made of two equal and opposite charges of magnitude q separated by a constant distance d (for example, the charges can be placed at opposite ends of a length d rod). The dipole is placed in a uniform, external electric field Er = E0 yˆ ...

I'm not understanding how the equation of the electric field due to an electric dipole is derived. This is how my book derives it: Say you have electric dipole composed of charges +q and -q a distance d apart, with the negative charge at the origin of the z-axis. Then, at any point z, the E...

The potential for an ideal electric dipole is given by V(x,y,z)= pz/(4π ε0(x+y^2+z^2)) In rectangular, spherical, and cylindrical coordinates: a) Find the electric field, E(x,y,z)= -∇V. (E is a vector, can't figure out how to denote that on my computer). b) By direct Calculation find...

how potential energy of electric dipole perpendicular to electric field is zero in this situation the torque is maximum so how P.E. can be zero please help

Homework Statement A sphere of radius a carries a uniform charge density \rho_0 in one hemisphere and the opposite charge density -\rho_0 in the other hemisphere. The charged sphere produces an electric potential \Phi (r,\theta,\phi). For r>>a, the potential to leading order is of the...

Homework Statement Electric dipole makes small angle with uniform electric field. Find the frequency of the oscillation using dipole moment p, moment of inertia I, and field magnitude E. Homework Equations Torque=I*(angular acceleration)=I*(theta)'' Torque=p*E*sin(theta) The...

Homework Statement Having problems with this subject. Given hydrogenic carbon, with binding energies of 490 eV (1s) 857.50 eV (2p) 925.54 eV (3p) 949.36 eV (4p). Find wavelengths of all lines due to electric dipole transitions between the levels. State which you expect to be strongest...

This is from Field and Waves Electromagnetic by Cheng page 602. THis is regarding to elemental dipoles. Given:

Homework Statement Hi, This is supposed to be simple, so I guess I miss something.. We have charge q at x1=d*cos (w*t), y=0, z=0. and charge -q at x2=-d*cos (w*t), y=0, z=0. I need to do Fourier transform to the charge density. Homework Equations The Fourier transform is ...

Homework Statement Derive equation of torque: G = p X E from equation U = -p\cdotE Homework Equations G = \int x \times \rho(x)E dV U = \int \rho(x)x \cdot \nabla\varphi dV The Attempt at a Solution I tried to figure how to represent G in a way that better express the nature...

Homework Statement write down an expression for the electric potential of an electric dipole at a large distance Homework Equations V=(qa cos(theta))/(4 pi epsilon r^2) The Attempt at a Solution is 'r' the distance they are talking about or is it 'a'? either way, if i substitute in...

Can we use Gauss's Law to calculate the field distribution around an electric dipole?

Homework Statement An electric dipole placed in a uniform electric field experiences a torque which tends to align the dipole parallel to the field. At the same time, due to two equal and unlike parallel forces Eq and -Eq acting at q and -q, the net force is zero. When the net force is zero...

Electric Dipole and Electric Potential.. and binomial approximation! Homework Statement An electric dipole at the origin consists of two charges +q and -q spaced distance s apart along the y-axis. a.)Find an expression for the potential V(x,y) at an arbitrary point in the xy-plane...

I am participating in a reading course on nonlinear optics, which is a little difficult since I haven't had any formal education in quantum mechanics other than the standard introductory solving of Schroedinger's eqn. in 1D. Happily this course takes the semiclassical approach, in which the...