Image charges Definition and 21 Threads

Consider two opposing mirrors. If they are exactly parallel planes I think there is only a single image in each but if they are slightly angled there appears an "infinite" number of reflections. Similarly, suppose we have grounded conducting planes instead of mirrors with a charge in between...

Homework Statement Homework Equations The Attempt at a Solution I'm sure my solution is wrong because of Φ(z=0) ≠ 0 I searched the internet for a similar problem but I couldn't. Any help will be appreciated.

Hi everyone, I have a question (or three) regarding Purcell's discussion of image charges, in pg 137-139 of the third edition of his EM book. He goes over the classic image charge example: a plane held at zero potential, and a charge Q a distance h above it. I'm fine with everything he...

Hi, I am learning about the method of image charges, but am struggling to sufficiently justify my answer. It appears to be correct, though it quite possibly isn't... 1. Homework Statement (please see attached item) Two semi-infinite grounded conducting planes (the shaded region in the...

Hi everybody, The situation is the classic one: a point charge q+ in a distance d above a conductor plane grounded: The conductor is grounded so V = 0, for z = 0. Also, far away from the system (x2 + y2 + z2 >> d) V --> 0 The argument to replace it for a q- charge seems perfect to me. What I...

Consider the following configuration: a grounded plane (very thin and with an infinite surface) and a positive (not important) point charge above it. What does grounded really mean? Can't I assume that it is neutral and it has infinitely many positive and negative charges? Because of the...

Hi all What if instead of charges and a surface, we were given a set of charges and image charges and have to find the surface, how would you do that? This is actually part of my homework but I'm pretty sure he doesn't want us to prove it mathematically (the case is obviously a sphere) so I...

This question seems to come up often, but I cannot find a satisfying explanation. There is a point charge +Q some distance above an infinite conducting plane. Supposedly, the electric field below the plane must be zero. I have trouble understanding why this is true. The total charge on the...

Homework Statement Hi! Bear in mind, before shooting me down, that I'm very new to electrostatics and extremely (i.e. today) new to the method of image charges, and all my learning is dodgy book-learning and not learning from asking the learned questions. This said, I just want my...

Hi, I'm trying to use image charges to find the force that apply on the following particle (on the attachment) , but it seems that I do something wrong - F=2q^2/(2a^2)-2cos(60)q^2/a^2 The gray section have 0 potential, so I've tried to put image charges like it is in the second attachment...

"A charged sphere is a distance d from the centre of an earthed sphere conducting sphere of radius a. An image charge (q') for this system is located at a distance b from the centre of the sphere where: q'= -(aq/d) and b=(a^2)/d Calculate the expression for the Electric field at point p...

Homework Statement (see attachment) Homework Equations The Attempt at a Solution I think i need to use method of image charges here but if i do that, i need to place infinite fictitious charges and finding the electric field at the surface of any of the plate would be very...

I have the below figure I took from my textbook from a section that explains how to calculate the capacitance of two transmission wires using image line charges. My question is that if I add two more conductors like shown below, how would it affect the line image charges? I'm not sure...

When using the method of image charges to solve a problem in electrostatics, how do we determine the volume of space in which our solution is valid? And how do we find the solution outside this volume? To be more specific, let's consider two examples. The first is the classic point charge above...

A point charge q is a distance d from a dielectric half-space (z < 0). We will solve for the potential outside of the dielectric, in the region z > 0. (a) Away from the point charge, what equation does V satisfy? Find the boundary conditions at the dielectric surface. (b) Find an image...

Homework Statement A point charge q is a distance d from a dielectric half-space (z < 0). We will solve for the potential outside of the dielectric, in the region z > 0. (a) Away from the point charge, what equation does V satisfy? Find the bound- ary conditions at the dielectric...

I was wondering if the "Method of image charges" could be extended even partly or approximately to oscillating charges. I am not considering nearly-static problems, but really radiating problems. After all, the Poisson equation and the wave equation are rather close ! Therefore, I thought...

Homework Statement The configuration is that there is a charge +q a distance 3d on the z axis and a charge -2q a distance d on the z axis. The xy plane is a grounded conductor. Find the force on the charge +q. Homework Equations I've place image charges: -q at z=-3d and +2q at z=-d. the...

Homework Statement We have a conducting and grounded wall for z<0, so \Phi=0 for z<0. In front of this wall, we place a homogeneous charged sphere with radius R and total charge Q. The center of the sphere has a distance of a to the front of the wall...

Homework Statement Two semi-infinite grounded plane conductors that intersect at the origin, with an angle of 60 degrees between them. A point charge of q is located some distance from the origin, and bisects the angle between the two conductors, where would the image charges be and what...

Someone's got to help me on these two. 1)Two semi-infinite grounded conducting planes meet at right angles. In the region between them, a point charge q is kept such that it is at a distance of 40cm from each of the two planes[i.e.(40,40)]. Find the position of its image charge/charges...