# Method of images for two charges and two planes

by wakko101
Tags: charges, images, method, planes
 HW Helper P: 5,004 I'm not sure I understand your problem description correctly... Is this the setup you are given (with the solid lines representing the grounded conductors)? If so, I don't think you can do this with just two images charges. In fact, I think you'll need an infinite number of image charges....just break the problem into pieces... [1] Where would you put an image charge, and what would its magnitude be in order to make the potential due to this image charge and the point charge at $z=\frac{R}{2}$ zero at $z=d$? [2] Where would you put an image charge, and what would its magnitude be in order to make the potential due to this image charge and the point charge at $z=-\frac{R}{2}$ zero at $z=d$? [3] Where would you put an image charge, and what would its magnitude be in order to make the potential due to this image charge and the point charge at $z=\frac{R}{2}$ zero at $z=-d$? [4] Where would you put an image charge, and what would its magnitude be in order to make the potential due to this image charge and the point charge at $z=-\frac{R}{2}$ zero at $z=-d$? These 4 image charges will cancel the potential due to your original charges at $z=\pm d$, but now there will be a non-zero potential at $z=-d$ due the first two image charges, and a non-zero potential at $z=d$ due to the second two image charges... [5&6] Where would you put two new image charges, and what would their magnitudes be in order to cancel the potential due to the first two image charges (image charges 1&2) at $z=-d$? [7&8] Where would you put two new image charges, and what would their magnitudes be in order to cancel the potential due to the second two image charges (image charges 3&4) at $z=d$? These 4 image charges will cancel the potential due to your first 4 image charges at $z=\pm d$, but now there will be a non-zero potential at $z=d$ due to image charges 5&6, and a non-zero potential at $z=-d$ due to image charges 7&8... ...Repeat Ad Nauseum until a clear pattern emerges...