Conductors Definition and 299 Threads

Say we have a solid wire made of Cu. It seems most electrons transport at the surface of the wire. Right? So is there any difference of the resistance if we have a hollow Cu wire (same diameter with the solid wire). I think the answer shoule be "yes". Right? Becasuse, the resistance R=p*L/A (p...

"In a static situation, the electric field of a conductor can have no component parallel to the surface coz this would violate the condition that the charges on the surface are at rest." would this statement be valid for electric field at the surface of an insulator? Explain your answer...

I had been reading Feynman lectures , and in it he has shown an argument which proves that E field inside an empty cavity of a conductor is zero.OK. Now he says a similar argument can be used to show that if there is some charge in a cavity of a conductor than the field outside must be zero...

Homework Statement http://img21.imageshack.us/img21/8079/orderyy3.th.jpg Homework Equations The Attempt at a Solution Well all I know that the smallest will be C, as it's 0 (inside the conductor), I think the next one is A, and I don't know about B and D

Why does the resistance decreases with increase in temp for semi- conductors?

Speed of EM travel through the good conductor is \omega/\beta I know the speed of signal travel in stripline is c/\sqrt{}\epsilon_{}r_{} My symbols don't look very good but I think you get what I mean. Obvious they are different. I am confuse because in both case EM wave travel in good...

This question was on my homework and I don't really understand how it has to do with magnetic fields. Homework Statement As 2 parallel conductors with currents in the same direction are moved apart, their force of A) repulsion decreases B)Repulsion increases C) attraction decreases D)...

Homework Statement A balloon, initially neutral, is rubbed with fur until it acquires a net charge of -0.60nC. (a) Assuming that only electrons are transferred, were electrons removed from the balloon or added to it? (b) how many electrons were transferred? Net Charge = Q = -0.60 nCHomework...

1.Two long, straight, parallel conductors carry equal currents and are spaced 1.0 meter apart. If the current in each conductor is doubled, the magnitude o the magnetic force acting between the conductors will be 1)Doubled 4) quadrupled. I chose 2 because I used the formula is F=ILB, so if I...

Is air a conductor or insulator? Does it matter about humidity? Also, is all forms of carbon insulators or conductors?

Homework Statement calculate a value for B at a distance of 50cm, in ,air, from a long straight cable carrying a current of 1000A. Homework Equations F=Bqv=BIl I=q\t = qv/l F=LIB The Attempt at a Solution i have not been able to calculate an answer as there are constantly two...

Homework Statement a straight conductor carrying 5A is separated by 10cm from a second parallel conductor carrying 10A in the same direction. at what distance from the first conductor (along the line connecting the two conductors) is the magnetic field zero? Homework Equations F_2 =...

Couple questions for you guys. 1. How does a single electric potential affect the atoms within a conductor. For example, if 100V is applied to a copper wire.. how do the copper atoms move/react to the voltage? (no current flowing) 2. Does positive or negative potential affect the wire...

Hi, I'm having a little trouble understanding why the field inside a charged conductor must be zero. I understand that when the charge is put on the conductor, they spread out to the surface such that the surface becomes an equipotential. But why does that mean the field inside must be zero?

Homework Statement Two parallel conductors carrying current in the same direction attract each other. If they are permitted to move toward each other, the forces of attraction do work. Where does the energy come from? Does this contradict the assertion in the previous chapter that magnetic...

[b]1. I am wanting to find more out about how electricity could be absorbed by some sort of conductor and then stored in a different containter from container a to container be. Saying that this were to be done from container a where electricity would be generated and roaming freely, needing to...

I read that charge resides on the outer surface of a charged (electrically) body. Is it meant only for charged conductors or all charged bodies including conductors or insulators? What are the specific points with respect to conductors and charges other than (i) conductors allow current freely...

Hi, I have problems with charge distributions of buckets and other conductors which has a cavity. If there is experiments, photos, detailed examples about this kind of charges then glad to learn the links in net. Suppose have a conductor like Faraday ice bucket. And tied two un-charged...

Homework Statement A coaxial conductor has the length L. The inner conductor of radius a carries a current I in the z direction. The outer conductor is very thin and has the radius b. Calculate the total magnetic flux enclosed within the conductors. Homework Equations Magnetic flux...

Homework Statement Two coaxial cylindrical conductors are shown. The inner cylinder has radius a = 2 cm, length 10 m, and carries a total charge of Q inner = +8nC. The outer cylinder has an inner radius b = 6 cm, outer radius c= 7 cm, length 10 m, and carries a total charge of Q outer =...

Conductors and Equipotential Lines - Fun! Homework Statement Consider the following two conductors. conductor A is grounded so that it has a voltage of 0 V and conductor B is charged up so it has a voltage of +20 V. Draw in the equipotential lines and then draw in the E field lines indicating...

Can someone tell me if I am on the right track with this. Problem: Two parallel conductors are 15cm apart and carry current of 8 amp and 12 amp. Calculate the size and direction of the force that the conductors exert on each one meter length of each other. 8 amp (out of page) o --------...

Homework Statement What would the equipotential or e-field lines look like when staring down the axis of the two finite cylinders? Will the E-field lines be radial or are they different because the cylinders aren't infinite?

I know airplanes are made of mostly nonconductors, but why do they have conducting wires embedded into the surface?

Physics - Conductors? Hi, I am currently enrolling Engineering first year and encountered a physics conceptual problem. Please explain to me please, thanks in advance 1. Does conductors have to be in electrostatic equilibrium? if not, how do you calculate the electric field of a...

Hi everyone! I am new to this forum. Can anyone help me to find any reference about this question: "What is the effect of bundling on decreasing the inductance of a transmission line?" I will be very grateful for any help. :rolleyes:

A little bit of confusion: Is it not correct to write ▼. E=ρ/ε0 inside a dielectric body. As far as I know we should write ε instead of ε0.[where ε=εr*ε0] Then why do we write ▼. E=ρ/ε0 inside a conductor?

A charge is placed on a speherical conductor of radius r1. this sphere is then connected to a distant sphere of radius r2 (not equal to r1) by a conducting wire. after the charges on the spheres are in equilibrium... is it reasonable to say that both spheres are at the same potential...

Homework Statement A hollow spherical conducting shell of inner radius b and outer radius c surrounds its concentric with a solid conducting sphere of radius a. The sphere carries a net charge -Q. The shell carries net +3Q. Find an expression for the potential difference from infinity to the...

can anyone tell me that how to calculate corona power loss for bundled conductor? I need formulae of it.

Homework Statement The two wires shown in Figure P19.38 carry currents of 5.00 A in opposite directions and are separated by 10.0 cm. Find the direction and magnitude of the net magnetic field at the following locations. http://www.webassign.net/sf5/p19_38.gif (a) at a point midway...

Is the fact that there could be no E-field inside a conductor purely experimental? I don't see any way to apply Maxwell's equations to prove this fact.

Conductors and co-axial cables!?? Say you have a long conducting hollow cylinder with some surface charge density \rho which is inside another hollow (uncharged) cylinder. What would the electric field be outside the outer cylinder? I am guessing that the e-field outside the outer cylinder...

Hi. If a conductor (A) touches another highly charged conductor (B) such as one on the Van De Graaff generator, then I move conductor A via a string away from conductor B. Does conductor A retain the charges that it had gained when it touched the highly charged conductor? If conductor A...

Hi, I believe that the free electrons in a piece of a conductor move randomnly until they are oriented in one particular direction by some external field. Does free electrons lose energy in this random motion??:confused:

A) By definition linear charge density is Q/L. So for the inner conductor with 2λ I want to say it is 2Q/infinity but this cannot be right. I am sure using Guass's law produces a correct answer but I cannot see anyway to relate it to λ or length of the conductors for that matter B) For...

Okay, say I have a coiled conductor below where the direction of the magnetic field is indicated in the North direction. +()()()()()- ---> N If I were to place a compass in the following position, what would happen? (a) COMPASS +()()()()()- (b) +()()()()()- COMPASS Okay, so...

Hi, I am confused about the electric field within a conductor. My textbook states that it is zero when charges at rest. Does this mean, the there is no electric field within the metal part of the conductor (let's assume this conductor is a hollow sphere), or the actual "empty" inside core of...

Problem: A solid coppper cube is placed in a constant Electric Field in x-direction. The faces of the cube are parallel to xy, yz, xz - plane and one corner is at the origin. Draw the field lines as they would be observed looking down on the cube towards the xy plane. Show at least two...

Hello. I just wanted to know if a material in the LIQUID state has a higher thermal conductivity than the same material in the SOLID state. I am thinking specifically about the metals, but I suppose it should be the same for non-metals (or not?).

Given that two spherical conductors of radii r1 and r2 are separated by x>>(both r), connected by a thin wire, and charged with 7 uC - how is the charge distributed between the spheres (no charge on wire)? I tried using charge density but: Qtot/A1+A2 = Q1/A1 + Q/A2 doesn't work by...

Hi, I would like to ask a question about grounding conductors. Suppose we have concentric spherical thin conducting shells (consisting of an inner conductor and an outer conductor). Suppose a charge of +Q is placed on the inner conductor. If we ground the outer conductor, my understanding is...

Can someone give me a couple hints to get me started on this problem, I am not sure where to go next. Infinite line of charge has charge per unit unit length 4.8*10^-6 and lies along the x axis. A second uniform line of charge with charge/unit length -2.4*10^-6 is parallel to the x-axis at...

This question actually has nothing to do with homework, since I am not a student, it's simply to satisfy my need for understanding the relationship between force and parallel conductor dynamics.. The ampere is that constant current which, if maintained in two straight parallel conductors of...

lets say you have the following situation: you have a cold pool of water, and hot air outside. how do you calculate the rate at which heat is exchanged (given Twater and Tair, the surface area of the pool, etc.)? Now, let's say you add a layer of a certain material x meters thick that has a...

I am going to attach the question along with this post so that you guys can see the questions and the diagram and be able to help me in answering my question better. I found the ccharge on the inner sphere and it is -3.928e-9 and the charge on the outer sphere is 8.15698e-9. Now I have to...

Here is the problems that's giving me trouble: Positive charge Q is distributed uniformly over each of two spherical volumes of radius R. One sphere of charge is centered at the origin and the other at x=2R. Find the magnitude and direction of the net electric field due to these two...

Hi, I was wondering, if I wanted to specialize in super conductors, would I have to focus on band theory?

the concept of wave guide is built that the fielt can't get through the conductiong surface?? but we use conductors to get the EM from space how this could happen can sny one give the ans