Conducting Definition and 562 Threads

Homework Statement A copper rod 90cm long is used to poke a fire. The hot end of the rod is maintained at 103 degrees Celsius and the cool end has a constant temperature of 25C. What is the temperature of the rod 24cm from the cool end? specific heat of copper: c = 387 J/kg*K thermal...

Suppose I put an (uncharged) hollow conducting sphere with inner radius a and outer radius b in an external electric field in the positive z direction. Apparently, the potential INSIDE the sphere -- that is, for 0 < r < a -- is zero. Can someone explain why this is? I understand that the...

Homework Statement http://i.imgur.com/j3uzQ.png" to screenshot of question Homework Equations The "Integral Form" the question refers to is the http://upload.wikimedia.org/math/0/3/1/0311484f33c932135c09ab12ca8d1a29.png" The Attempt at a Solution The hint hasn't really helped me...

Firstly, I'm a bit confused about EM wave propagation. Take the picture you see everywhere illustrating the perpendicularity of E and B in a traveling EM wave (like this http://web.onetel.net.uk/~gdsexyboy/em_wave.jpg) -- does that actually illustrate the magnitudes of E and B at a particular...

Homework Statement There are two conducting spheres, one hollow outer sphere which originally had +60nC of charge on it, and a smaller inner sphere enclosed by the hollow outer sphere which contains +20nC of charge. Homework Equations INT(E.DA) = Qenclosed/epsilon0 The Attempt at a...

Homework Statement A conducting rod slides down between two frictionless vertical copper tracks at a constant speed of 4.5 m/s perpendicular to a 0.56-T magnetic field. The resistance of the rod and tracks is negligible. The rod maintains electrical contact with the tracks at all times and...

Homework Statement A long circular solenoid of radius a and N turns per unit length has its axis in the z direction. A small highly conducting ring, or area A, resistance zero but self inductance L, is place with its plane horizontal and its centre on the axis and near the top of the...

Homework Statement Two identical long straight conducting wires with a mass per unit length of 25.0 g/m are resting parallel to each other on a table. The wires are separated by 2.5 mm and are carrying currents in opposite directions. a) If the coefficient of static friction between the...

Homework Statement What is the electric field if r=a and r=b? Reference:http://www.youtube.com/watch?v=BcuQ2c_WrMc" 2:11 And what if the net charge is just -Q on the conductor instead of -3Q? Will the electric field at r>b be 0? Reference: Same video, 3:00-3:10 Homework Equations...

Given the equation for the potential "on" a non conducting sphere how can the potential and electric field inside the sphere be calculated? If there is a potential on the sphere am I to assume that there must therefore be a charge build up in the sphere? Is this just calculated by the Laplace...

Homework Statement A 0.100m long solenoid has a radius of 0.05m and 15000 turns. The current in the solenoid changes at a rate of 6.0 A/s. A conducting loop of radius 0.0200m is placed at the center of the solenoid with its axis the same as that of the solenoid. Determine the mutual...

Homework Statement Consider two coaxial conducting cylinders with radii a and 3a and length L. The region a<r<2a is filled with a material of conductivity σ1, and the region 2a<r<3a has conductivity σ2. (Assume ε1=ε2=εo.) The inner cylinder is held at potential V0 and the outer cylinder at...

Homework Statement Two charges +Q and -Q are a horizontal distance a apart and a vertical distance b above a large conducting sheet. Find the components of the forces acting on each charge. Homework Equations The Attempt at a Solution Ok well I've tried to solve this using image...

Homework Statement This isn't about a specific problem, but it is based off of a homework problem. There is an insulating sphere (from radius 0 to a), and it is concentric with a spherical conducting shell (from radius b to c). If I know the charge of the insulating sphere and the net charge...

Homework Statement Find the work done to move a test charge with charge q from the origin to the edge of a spherical conducting shell which surrounds it, also of charge q. (Shell is of radius R). Homework Equations W = int(F.ds) where W = work done, F = force The Attempt at...

Suppose I have a wire with a net charge (lets say negative) in a uniform electric field from another source, such that the field lines are parallel to the wire. I want to work out the electric field surrounding the wire. Because the wire is conducting, the electric field inside the wire will...

1. An extremely long, solid, nonconducting cylinder of radius R1 = 50 cm has charge density given by p = kr, where k = +2.0 microCoulomb/m^4 and r is the distance from the center of the cylinder. It is surrounded by a solid, conducting, cylindrical shell of inner radius R2 = 75 cm, outer radius...

Homework Statement Two parallel conducting plates that are in deep space are brought to a potential difference of 3500 V, and a small pellet of mass 6.95 mg carrying a charge of 6.70 × 10-7 C accelerates from rest from the positive plate. With what speed will it reach the other plate...

[b]1. Homework Statement A long, solid, non-conducting cylinder of radius 8 cm has a non-uniform volume density, ρ, that is a function of the radial distance r from the axis of the cylinder. ρ = A*r2 where A is a constant of value 3 μC/m5. Homework Equations Gauss's law EA = Q/(epsilon)...

Conducting Sphere "shielding" an electric field Hello. I have a question regarding a problem that I have seen printed many times in various books and which I saw on a test today: A hollow conducting sphere contains 2 charges, q_1\;and\;q_2 . Outside the sphere are two additional charges...

Homework Statement A thick-walled, conducting spherical shell has charge q = +10 mC, inner radius R1 = 10cm, and outer radius R2 = 50 cm. A point charge Q = -20 mC is located at the center of the shell. Describe the the charge distribution in the shell. 2. Given answer +20 mC on...

Consider a charged spherical conducting shell. I understand that Gauss's law implies that there is no charge on the inside surface of the conducting shell. Now consider a charged spherical conducting shell with lots of holes cut uniformly all over it. Would Gauss's law still imply that...

Suppose that we have a wire that connects the two poles of a DC battery. The current produced indicates the presence of some Electric Field within the wire, having a constant magnitude and a direction that follows its path. Now the question is : What is the source of that Electric Field...

Dear Physicists, I am currently thinking of a way of inducing a current in a conducting material by a magnetic field. I am not good at magnetism and electricity at all, but I think it should look like the picture below. By the way, the material in the middle does not move. Does anyone...

Hi all Suppose we have a conducting shell (which is not necessarily a sphere) and no electric charge inside. Is the electrostatic field inside the conducting shell always zero? (even if there is some charges outside the shell) What if the shell is grounded? If the answer is yes, how it...

Homework Statement There's a conducting spherical shell with Q = q2 and V =100v and outter radius R Homework Equations V=k*Q/R The Attempt at a Solution First I calculate the E field using Gauss law, and I get E=q2/4*Pi*E0*r Integrating the E field to get the potential V y...

Homework Statement A conducting loop (assumed to be infinitely thin) is being moved along time the x -axis as shownin figure 1the current in the wire is changing with i(t)=cos(wt) the loop position 2-tm t >0 http://img3.imageshack.us/img3/9530/adszbv.jpg Uploaded with ImageShack.uswhat...

I am referring to David Griffiths "Introduction to Electrodynamics" 3rd edition, page 141, example 3.8. The example is regarding to a conductive ball radius = R and contain no charge being put in the middle of a constant electric field \vec {E_0} = \hat z E_0. My problem with the example...

Homework Statement Two concentric conducting spheres of radii a and b (a < b) are separated into four hemispheres by a nonconducting sheet. The upper ( 0 < θ < π / 2 ) outer (radius b) and lower ( π / 2 < θ < π ) inner (radius a) hemispheres are kept at potential +V. The upper inner and lower...

X and Y are two identical conducting spheres separated by a distance d. X has a charge of +6µC and Y has a charge of -2µC. The electric force between them is +F (i.e. attractive). The spheres are touched together and are then returned to their original separation d. What is the new value of the...

Homework Statement Empty cubic box of dimension "a" with conducting walls. Two opposite walls are held at a constant potential V, while the other walls are grounded. Find an expression for the electric potential inside the box. (Assume box centered on the origin, walls are all normal to one...

Homework Statement Griffiths 3.36: Two straight wires having equal and opposite line charges are situated on either side of a conducting cylinder (all the wires and the cylinder are "long", so we can ignore edge effects--this is undergraduate electrostatics, after all!). The cylinder has no...

Homework Statement A solid nonconducting sphere of radius R carries a nonuniform charge distribution, with a charge density ρ = ρsr/R, where ρs is a constant and r the distance from the centre of the sphere. Show that i) the total charge on the sphere is Q= πρsR3 and ii) the...

Homework Statement You don't really need to read the top paragraph. A Geiger counter is used to detect ionizing radiation. The detector consists of a thin wire that is surrounded by a concentric circular conducting cylinder. A high voltage is applied to the wire so that it has a positive...

Homework Statement A hollow sphere of gold floats in a large lake of oil of dielectric constant \kappa=3.3. The sphere is half immersed in the oil, and has a total charge of 2.2*10^-6 Coulombs. What fraction of this electric charge on the sphere is above the oil surface? Homework...

I'm trying to find the total charge on a conducting surface but am stuck at the last part of this integral. Maybe I'm just dumb but it looks really complex to me and I can't seem to figure it out. http://www.flickr.com/photos/54479402@N07/5045800952/#/photos/54479402@N07/5045800952/lightbox/...

Hi, I received this question on my exam today and it stumped me... Conducting spherical shell of inner radius 0.045m and outer radius 0.18m, which has a net charge of zero. A charge Q of 5.5x10-5 is placed at the center, find the electric fields at point A (0.03m), point B (0.06m), and...

I'm having trouble using Guass' law to find electric fields. Where is the magnitude of the Electic field that you end up calculating? I had assumed it would be anywhere on the Gaussian surface, but it doesn't make sense now that I think of it. for instance, calculating the field of a charged...

Hi, Can anyone suggest a conducting liquid that does not get electrolysed when current passes through it ? By liquid i mean anything, a salt solution, a liquid metal...The only restricting factor is that is should be in liquid state at room temperature(i.e does not require extra...

Homework Statement An infiinitely long solid conducting cylindrical shell of radius a = 4.5 cm and negligible thickness is positioned with its symmetry axis along the z-axis as shown. The shell is charged, having a linear charge density λinner = -0.35 μC/m. Concentric with the shell is another...

Homework Statement I have found this problem in Feynman Lectures on Physics vol. 2: Two equal conducting spheres, one with the total charge of +Q and the other with a total charge of -Q, are placed at some distance from each other. What is the force between them? Homework Equations...

Potential of Concentric Cylindrical Insulator and Conducting Shell...Please Help Homework Statement An infinitely long solid insulating cylinder of radius a = 3.6 cm is positioned with its symmetry axis along the z-axis as shown. The cylinder is uniformly charged with a charge density ρ =...

Homework Statement 25. A semi-infinite nonconducting rod (i.e. infinite in one direction only) has uniform positive linear charge density lambda. Show that the electric field at point P makes an angle of 45 degrees with the rod and that this...

If a charge is placed inside a spherical conducting shell, is the total electric field inside it zero? I am thinking that if the charge is positive, then the conducting shell will have an equal amount of negative charge on its inner surface, therefore the E field should be zero inside, right?

Homework Statement Two large conducting plates are separated by a distance 'L', and are connected together by a wire. A point charge 'q' is placed a distance 'x' from one of the plates. Show that the proportion of the charge induced on each plate is 'x/L' and '(L-x)/L'. (Hint: pretend the...

Homework Statement A long, straight copper pipe of inner diameter 16mm and outer diameter 24mm carries a current of 100A. Calculate the magnetic flux density at distances i)5mm, ii)10mm and iii)15mm from its axis? Answer : i)0, ii)9*10^-4T iii) 13.3*10^-4T Homework Equations I...

Homework Statement A conducting sphere of radius 0.01 m has a charge of 1.0 × 10–9 C deposited on it. The magnitude of the electric field in N/C just outside the surface of the sphere is Homework Equations E=kq/r^2 EA=q/eo The Attempt at a Solution I tried the first equation...

There is this conducting rod being moved to the right a constant speed v by a mechanical force F along 2 parallel , smooth, and horizontal conductors in a uniform vertical magnetic field of flux density B. The question is why is the speed constant although its being moved by a force ,F...

Homework Statement So my textbook has a lot of example of conducting rails moving horizontally with unknown variables of F and B, but how would you approach a problem that has such a device pointed vertically with the moving bar droping? let's say R and B are known and we need to find...

Point charge +Q is placed close to a very large conducting plane. A professor of physics asserted that the field caused by this configuration is the same as would be obtained by removing the plane and placing a point charge -Q of equal magnitude in the mirror-image position behind the initial...