Dipole Definition and 796 Threads

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...

NOTE: BEFORE YOU RESPOND PLEASE KNOW THIS IS AN ASSIGNMENT QUESTION (worth 1/6 % of total subject) AND AS SUCH I DO NOT WANT AN ANSWER TO BE GIVEN TO THIS PROBLEM. I have tried this question many times in different ways and unfortunately I am unable to get any of these multiple choice answers...

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...

Homework Statement an electrical dipole is placed at the centre of the sphere,the electric flux due to dipole is? i know the answer is zero but i don't find my reasons satisfactory pls post reply (i thought if the flux are normal to the centre the cos90 is zero hence zero) pls pls...

I would like to know that 1) Is there a point where the electric field is zero from a dipole? 2) If the point is very far away from a dipole, how is the electric from the dipole? I mean, for example, if there is a charge...

Hello, I have doubts with this problem, I'm not sure, if my solutión is right, so, here we go Let's two equal charges with the same charge but opposite signs, positive and negative, in a circle, such a distance between them is constant and equal to diametre of the circle. Both charges, turn...

hey, I was asking myself a few questions about the selection rules for EM dipole radiation which occurs if electrons "jump" into lower bound states according to the selection rules. now I know that the full explanation about matrix elements of the dipole operator comes from fermi's golden...

Hi Why does a bond stretch or vibration have to cause a change in dipole moment to be IR active? Presumably all vibrational modes depend on energy aborption to occur whether they cause a change in dipole or not. I'm presuming that only those vibrational modes that cause a dipole change are...

Homework Statement Given a permanent dipole, call it pNO, at the origin pointing along r1 (general vector, not along any particular axis). A polarizable atom as at position r2. What is the induced dipole moment, call it pHe, of this atom in terms of pNO and r2? Homework Equations...

Homework Statement Determine the dipole moment, \mathbf{p}, of a sphere of radius R with a uniform volume charge, total Q, with respect to its center. Homework Equations \mathbf{p}=\int \mathbf{r} \rho(\mathbf{r}) d\tauThe Attempt at a Solution I know that \mathbf{p}=\mathbf{0}, but I have a...

When I am dealing with dipole radiation, I faces a difficult problem. Is the phase of the radiation the same as pump wave?

I was just wondering... say you have a dipole, and you wanted to find the net electric field right in the middle. The electric field from the electron will be: E = k(-1.60*10^-19)/r^2 The electric field from the proton will be the same magnitude, but opposite direction...

I know that the potential at any point P is the sum of the two potentials of a dipole. But we make two assumptions to get an equation: 1 - the distance from the dipole to P is very large relative to the dipole distance (d) 2 - we also make the assumption that r2 - r1 = dcosθ r2 and r1 is...

Do Gluon's have a magnetic dipole moment ? I hope this is the right place to post this.

Homework Statement Example: Problem 5.33 Show that the magnetic field of a dipole can be written in the following coordinate free form: Homework Equations http://teacher.pas.rochester.edu/PHY217/LectureNotes/Chapter5/LectureNotesChapter5138.jpg...

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...

In my electromagnetic engineering class we were talking about Hertzian dipole antennas with an oscillating current source (transmission line) driving the antenna. As part of the description of the behavior as the two ends of the antenna have opposite charges an electric field is created from...

simple magnetic dipole moment with impossible field lines? clueless. Hello, I'm taking a first year university course in electromagnetism. At a certain point we came upon the torque on a current loop in a uniform magnetic field. There we introduced the magnetic dipole moment \overline{\mu} =...

Homework Statement There are three charges arranged on the z-axis. Charge +Q_2 at the origin, -Q_1 at (0,0,a) and -Q_1 at (0,0,-a). Using spherical polar coordinates (i.e the angle \vartheta is between r and the positive z-axis), find the potential at a point with a distance r from the...

Homework Statement Hi there, I am kind of new to this site, so please bear with me. On the more advanced physics forum page, there was a question about dipole moments, and the way the help had been described was a bit over my head. I am posting this for clarification purposes because this is...

Homework Statement E-field at (2[m], 30⁰, 90⁰) is E = 4aѳ [V/m]. Find the magnitude and direction of the dipole moment p. Homework Equations I know that I need I need to solve for the equation: p = Qd, where Q is the point charge at the given point and the distance between +Q and -Q, which...

As in Feynman's lecture on physics vol 2, he showed that the "true energy" of a magnetic dipole(current loop) in an external B field is m*B, not -m*B. Basically the argument is if you want to pull a current loop from infinity to the final position, you must do extra work to keep the current in...

Homework Statement A circular coil having 20 turns and a radius of R = 12.8 cm carries a current of 2.70 A. It is placed in a uniform magnetic field of 60.0 mT. The initial angle between the magnetic moment of the coil μ and the magnetic field B is 26.0o. 1)Calculate the magnetic dipole...

May anyone help me with these questions 1 why is a dipole neutral as it completely resembles a system of two charges 2 i know probably its very advanced, but can anyone give me out a scope on wave function and its relation to energy of an orbital 3 am not sure if this is the right forum...

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...

Homework Statement ..Is it possible to find the Magnetic Dipole Moment of a point particle with spin quantum number 2 and mass equal to that of a proton. I'm not sure how to start this question as there's nothing on it in the textbooks I have! Thanks

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 The problem is: Show that the components of \vec{E} due to a dipole are given at distant points, by Ex=\frac{1}{4\pi\epsilon{o}} \frac{3pxz}{(x^2+z^2)^{5/2}} and Ez=\frac{1}{4\pi\epsilon{o}} \frac{p(2z^2-x^2)}{(x^2+z^2)^(\frac{5}{2})}}...

Homework Statement The problem is: Show that the components of \vec{E} due to a dipole are given at distant points, by Ex=\frac{1}{4\pi\epsilon{o}} \frac{3pxz}{(x^2+z^2)^{5/2}} and Ez=\frac{1}{4\pi\epsilon{o}} \frac{p(2z^2-x^2)}{(x^2+z^2)^(5/2)}}...

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 am at a loss for how to start this problem. t = r x F and F = q(E + v x B) i know but there is no external E or B field its just a dipole that moves with a speed v in the x direction the dipole is oriented with +q at (d,d,0) and -q @ (-d,-d,0) how do i derive a torque?

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 A certain electric dipole is placed in a uniform electric field E of magnitude 20 N/C. Figure 22-59 gives the potential energy U of the dipole versus the angle θ between E and the dipole moment P. What is the magnitude of P? Homework Equations U=p(dot)E The...

Homework Statement A dipole of moment 0.50 e · nm is placed in a uniform electric field with a magnitude of 8.0 104 N/C. What is the magnitude of the torque on the dipole for each of the following situations? (a) the dipole is aligned with the electric field 0. N · m (this is correct)...

Homework Statement Calculate the magnetic vector potential A at a point p located at a distance r from the axis of an oscillating dipole of length s. It is assumed that r\gg s and that the current is the same throughout s. Homework Equations r=\sqrt{(x^2+(z-z')^2)}, where x,z is the...

Find the first integrals of motion for a particle of mass m and charge q in a magnetic field given by the vector potential (scalar potential \Phi= 0) (i) of a constant magnetic dipole m_{d} A=\frac{\mu_{0}}{4 pi}\frac{m_{d} \times r}{r^{3}} Hint: Cylindrical coordinates are useful...

i want to learn about magnetic dipole moments but don't have a good grasp on it

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 All, I'm currently wrestling with trying to understand the theory behind radiation from a dipole antenna. Little by little I'm putting the pieces together but I need verification regarding a conclusion that I have drawn although I have not read it. An antenna has a near field and a far...

Dipole Moment! Ok I'm very tired because I've spent the past 50 minutes trying to figure out a problem that should take only 5. Someone please just take 2 minutes of your time to save me 20 more minutes. THis is a simple problem yet I cannot do it on my own, without my textbook and with what...

Homework Statement A point charge q is situated a large distance r from a neutral atom of polarizability \alpha. Find the force of attraction between them. Homework Equations \vec{E}_{mono}(r)=\frac{q}{4\pi\epsilon_0r^2}\hat{r}...

Hi, 1st year chem guy here...I'm missing this idea. Is it all based upon Electronegativity? I can see why HBr or HCl and other 2 atom compounds would be polar. 2 atoms with different charges or even sizes creating an un-even pull. I'm guessing H2O is polar as the 4 remaining electrons on...

Homework Statement Show that the electric field of a "pure" dipole can be written in the coordinate-free form E_{dip}(r)=\frac{1}{4\pi\epsilon_0}\frac{1}{r^3}[3(\vec p\cdot \hat r)\hat r-\vec p]. Homework Equations Starting from E_{dip}(r)=\frac{p}{4\pi\epsilon_0r^3}(2\cos \hat r+\sin\theta...

Homework Statement We know the magnitude of the electric field at a location on the x-axis and at a location on the y axis, if we are far from the dipole. (a) Find \DeltaV= V_p - V_a along a line perpendicular to the axis of a dipole. Do it two ways: from superposition of V due to the two...

I just have a quick question about finding the average force of a dipole. I am given the expression (after I derived it anyway): \textbf{F} = -3 \left( \frac{e-1}{e+2} \right) \frac{R^{3}}{d^{7}} \left[4( p \bullet \hat d)^{2} \hat d + p^{2} \hat d - (p \bullet \hat d) \hat d \right]...

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...