Conductor Definition and 790 Threads

Hi Guys, :smile: The following query would sound a bit ridiculous and abstract but it suddenly popped up in my head. :-p What would happen if I were to apply a purely sinusoidal AC voltage across a zero resistance conductor (theoretically, a super conductor) ? Zero resistance would mean...

Hi, Frankly, I'm new to this forum. So please do guide me if I posted wrongly. I need some help in sizing the neutral wire. For a 3 phase 4 wire system (3Ph + N), what is the recommended size of the neutral conductor. Should it be the same as the phase conductor or should it be 50% of the...

Maybe one day I'll be able to answer questions instead of ask them... Is there a critical ac frequency for a super conductor? I know there's a critical current density and critical field, but assume we stay below those levels. Thanks.

I have two conductors in no magnetic material such as copper. One has diameter 20mm and other has diameter 50mm and both through by same current about 100A. Where do i have the maxi magnetic field on surface of conductor...I tinks on conductor with diameter 20mm..Is exactly ?

Homework Statement Homework Equations l = 0.02 m r = 0.3 m E = \frac{-d\phi}{dt} \phi = BA The Attempt at a Solution A = \pi 0.32^2 - \pi 0.3^2 = 0.0124\pi ...Area "cut" by conductor \phi = 1.5a_r0.0124\pi = 0.0186\pi a_r ...change in flux in one revolution 1600...

Homework Statement Show that any charge distribution in a conductor of conductivity σ and relative permittivity κ vanishes in time as ρ = ρ0exp(−t/ζ) where ζ = κǫ0 σ Homework Equations Maxwell's equation ∇ · D = ρfree equation of continuity for a free charge density ∇ · Jfree =...

[solved] electric potential: point charge in a hollow charged conductor Homework Statement A hollow spherical conductor, carrying a net charge +Q, has inner radius r1 and outer radius r2 = 2r1. At the center of the sphere is a point charge +Q/2. d) Determine the potential as a...

Homework Statement A long circular rod of radius R, made of conducting material, has a cylindrical hole of radius a bored parallel to its axis and displaced from the centre of the rod by a distance d. The rod carries a current I distributed uniformly over its cross-section. Consider the...

Homework Statement A. Two infinite thin sheets of charge are placed perpendicular to the x axis. The surface charge densities of the two plates are (SC density 1 = 8.5 C/M2) and (SC density 2 = 1.5 C/M2. Placed near plate 2 is a think conducting metal plate with a (SC density of -3.0 C/M) Find...

Homework Statement http://www.aijaa.com/img/b/00815/3678868.jpg Homework Equations B= \frac { \mu _0}{2 \pi r}I d \phi = \vec{B} \cdot d \vec {A} The Attempt at a Solution I know the magnetic field of the conductor is B= \frac { \mu _0}{2 \pi r}I. And in order to solve the magnetic flux...

An uncharged solid spherical conductor is placed in a constant electric field \mathbf{E_0}. Find: a) the reulting potential and electric field b) the induced surface charge density and sketch the field lines c) the force on the sphere I don't have a scooby where to start here so any help...

You are given a piece of metal of one square cm area and 10cm long. You do not know whether it is a conductor or a semiconductor. Devise some experimental setup to know the nature of the material.

Hi all, My name is aldo and I am mechanical enginner. My job is specialist in non-destructive testing in aeronautic sector. The typical method for to magnetize this components is circular magnetization by central or offset central conductor. Usually the central conductor is a copper bar. When I...

Is E=0 in super conductor also? I read in the below site that static electric field goes some depth into super conductor? Is this true? Classical physics says E=0 in conductor. so, what is the difference ordinary conductors and super conductors? http://adsabs.harvard.edu/abs/2002APS..MARA12009T

Homework Statement Show the electric field inside an empty cavity in a conductor is zero, even if there is a charge outside the conductor. If a charge is placed inside the cavity, will there be an electric field outside the conductor. Explain Clearly. Assume that both the conductor and cavity...

I have a few questions on three circuits problems that I have already solved. I explained how I arrived at my answers and included diagrams. I would appreciate any help in confirming that my answers are correct. Thank you! 1. The diagram below shows electric currents in conductors that meet...

Homework Statement The question is as shown on the attachment. Homework Equations F = BIL The Attempt at a Solution To find the magnitude of the force I used the equation "F = BIL" and then I put in the values for each (B=0.25, I=15, L=0.20) and I got an answer (magnitude) of 0.75...

I need to calculate the size of a force acting on a conductor if the length of the conductor is 200mm, the flux density is 2 tesla and the current flow is 5A. thanks, cs

Suppose you have a long wire. One end of the wire is close to a very very strong source of electric field. It is my understanding that the electrons responsible for bonding in a metal are also those responsible for conduction. If you have an extreme electric field near to the conductor, and...

[b][FONT="Arial Black"]1.Prove that free charge resides on the surface of a conductor.(Using Gauss's law or laws of capacitance) Homework Equations The Attempt at a Solution I could not figure out how to prove this using Gauss's law,though i tried to solve it using the laws of capacitance.This...

I am reading an electrodynamics book to grasp the concept of bound and free charge, esp in conductor and dielectric. I got lost with the text on the book. Can anyone please help me understand the concept well?

Homework Statement Find the surface charge induced on an infinite conducting plate by a point charge +q at a distance a from the plate. The Attempt at a Solution As you probably know, this problem can be solved using the well-known fact that the induced electric field is equivalent to...

Homework Statement Basically there is conductor shell which is in the shape of a semicircle. It extends to infinity. (Think of this as like half of a cylindrical conductor shell). The radius of this shell is A, and it carries a total current of X. The shell extends infinitely into the...

Does anyone know of an experiment or know where I can find an experiment to compare the heat gain or heat loss by a conductor and an insulator?

Homework Statement The question given is an electromagnetic wave incident on a vacuum metal interface. The wave is incident normally. We're given that the metal is a good conductor i.e. \omega \tau <<1 where \tau is the collision time of the metal and omega is the angular frequency. The metal...

Consider an infinitely long stationary conductor which carries a steady uniform current. 1. At an arbitrary Test Point outside the conductor the Electric Field should be ZERO according to Maxwell's Equation. 2. But if Special theory of Relativity is considered, the moving charges...

Homework Statement A charge q of mass m is released a distance d from a semi-infinite grounded conductor. How long will it take the charge to reach the conductor? So I tried this using the method of images, and I can easily find the force on the charge a distance d away: F = -q^2 zhat /...

Homework Statement 13) A large metallic sphere insulated from ground is charged with an electrostatic generator while a student standing on an insulating stool holds the sphere. Why is it safe to do this? Why would it not be safe for another person to touch the sphere after it had been...

Homework Statement In the field of a point charge over a plane, if you follow a field line that starts at the point charge in a horizontal direction, that is, parallel to the plane, where does it meet the surface of the conductor? Homework Equations The problem 'hint' is "You'll need Gauss'...

1. If you have two identical conducting spheres A and C. A carries a charge and C is uncharged. Sphere C is touched to A. How does the charge change on A? 3. I know since C was initially uncharged, after it touched A it becomes charged. IF A was positively charged C would become...

why is the potential constant inside a spherical conductor/insulator? Are there boundary conditions that needs to be satisfied in order to make the potential zero? this is just a general question since most of the physics problems that I do needs the potential to be constant inside the sphere.

Hi, I have a doubt in my mind about the behaviour of Good Conductors. So far whatever we studied, 1. Good Conductors have free electrons to move and carry the charge, 2. Electric charge is being carried in form of electrons. Now the question is Suppose, we have piece of good...

[My understanding is that in a conductor which is conducting a current there is and electric field present also. If the electric field can be found by E= - \frac{dV}{dl}, what is E in a conductor. On a conductor in a DC circuit the potential is the same everwhere on that conductor, so I believe...

Homework Statement In a vacuum diode, electrons are "boiled" off a hot cathode, at potential zero, and accelerated across a gap to the anode , which is held at positive potential V0. The cloud of moving electrons within the gap(called space charge) quickly builds up to the point where it...

Homework Statement An isolated capacitor with capacitance C = 1 µF has a charge Q = 29 µC on its plates A conductor is inserted into the capacitor with thickness of the conductor is 1/3 the thickness of the capacitor and is centered in between the plates of the capacitor. What is the...

Anyone can tell me why there is a -ve for the z= -r cot theta for the picture shown below? thanks!

For insulators the excess charge stays on the outside of the object. For conductors the excess charge travels through the sea of electrons until the net charge inside the object is zero with the rest of the charges pushed to the outer edges of the conductor. So with both the excess charges...

Homework Statement In a vacuum, a straight conductor has 18-A current that goes upward. An electron is traveling at 8.92 x 10^4 m/s. If the electron is 0.2 m from the conductor and its instantaneous velocity is parallel to the conductor (albeit heading downward), find the magnitude and...

I have some questions about electric field inside a conductor. In fact, if a neutral conductor is placed within a capacitor, why its electric field inside the conductor at the beginning not zero, then it is zero? Why does the field disappear? How about if a charged conductor is placed...

Homework Statement Hi all. I have two questions. 1) The electric field of a uniformly charged, infinite plane is given by: E = \frac{\sigma }{{2\varepsilon _0 }} The electric field just outside a conductor is given by: E = \frac{\sigma }{{\varepsilon _0 }} Why are these expressions not...

A cylindrical aluminium bar is placed vertically on an insulating surface. The radius of the bar is R and the length is L. The bar has a total charge of zero. Compute the electric field inside and outside the bar. This is a Homework problem given by Count Iblis to the PF community :cool:

Why is it that the current in an ideal electric conductor resides in a very thin layer at the surface of the conductor?

Homework Statement A charge Q is placed at the center of a conducting spherical shell of inner radius R1 and outer radius R2. The sphere has no net charge. Ok, I have some statements for this setup. Would you be kind to check them? The Attempt at a Solution 1) The electric field in a...

Hi, As I understand it, the potential of a charged conductor is the work done in bringing a unit positive charge to its surface from infinity. Is this correct? When a conductor is grounded, then any excess electrons on it go into the ground. Is this correct? If so, why? Assuming that...

What is the difference, apart from the Meissner effect? What are the practical consequences of Meissner effect? How can I, by experiment, deduce whether a material is an ideal conductor or superconductor? superconductor has zero resistivity. So what happens when we apply a potential...

Hi, Just got a doubt, which is probably silly but nonetheless cannot solve. Say you have a conductor placed in an external uniform electric field. We know that charges will be induced on the conductor and distribute on its surface as to nullify the field inside the conductor. Then, at...

Homework Statement http://img228.imageshack.us/img228/2536/physicsme1.th.png Homework Equations I = \int \int J . dS V = - \int E . dl V = IR The Attempt at a Solution I'm not really sure how to get started on this problem, generally I would start with Laplace's equation but...

Homework Statement A heavy conductor (mass m, length [FONT="Courier New"]l, resistance R) is suspended by two springs each with spring constant k, and connected to a battery with electric potential V as shown in the figure. A magnetic field B is now imposed. The acceleration of gravity is 9.8...

Arright this appeared in my exam tommorrow and I was baffled by the question...Is there any way to store the charge in single conductor or the answer was "not possible" ?

i wanted to ask why the electric field inside a hollow conductor zero throughout and not just at the centre.