Conductor Definition and 820 Threads

Homework Statement A metal sphere with charge q=3.7 μC and radius r=3.1 cm is concentric with a larger metal sphere with charge Q=13 μC and radius R=5.6 cm. (a) What is the magnitude of the potential difference between the spheres? If we connect the spheres with a wire, what then is the charge...

So the potential inside a conductor is constant. Does this mean that if there were a conductor, B, inside another conductor, A, the charges of A/B would redistribute such that the electric field inside would be zero (hence constant potential)? This seems logical but a bit too easy? Also, if it...

I read somewhere that conductors don't really store charge? How can this be correct? When a conductor is charged by conduction, the electrons spread throughout the surface of the conductor. Doesn't this mean that the capacitor is storing this electricity? What prevents conductors from being...

Hello! Is it possible to detect THz radiation (300 GHz - 1 THz) with conductor or dipole antenna used to detect radio waves? I know that THz radiation may be detected in spectroscopic set-ups with a photoconductive antenna based on the semiconductor. In this case, the light from laser create...

Homework Statement Is it possible to introduce local charge on a conductor? Homework Equations - The Attempt at a Solution I know that electrons can move freely from atom to atom in the conductor, so if you introduce excess electrons to the conductor, they'll spread out and there won't be a...

Homework Statement Homework EquationsThe Attempt at a SolutionAssuming zero of the potential is at infinity , the potential refers to the potential difference between the each conductor and infinity . The potential of the uncharged conductor would be due to three charges, positive induced...

I'm currently struggling with the Moving Conductor and Magnet Problem. https://en.wikipedia.org/wiki/Moving_magnet_and_conductor_problem Look at this section: https://en.wikipedia.org/wiki/Moving_magnet_and_conductor_problem#Transformation_of_fields.2C_assuming_Galilean_transformations What is...

Hi, I have a question regarding electricity. Suppose I have a conducting wire secured to a table so it's completely stationary. Suppose I attach a resister of some small amount of resistance, perhaps a light bulb.Then I take a magnet and slowly move the magnet near the conductor so that a...

Here's a random thought that I don't as yet have a satisfactory solution: Let's assume we have a copper column resting on an insulated table. Copper is an electric conductor, which means that some electrons within the copper column move freely throughout the column, subject to electromagnetic...

I saw this and thought it was interesting. If one can get beyond the pretentious music, super annoying robotic narration and ignore the completely off the wall theory discussion there remains a reasonably well documented experiment. The measurement shows the B field about a conducting cylinder...

Homework Statement A flat capacitor formed by two square plates of side 0.3 m which are 2 mm apart. Source keeps voltage 250 V on the plates. What current flows between the plates and the source if the condenser is immersing in kerosene at velocity of 5 mm / s? The relative permittivity of...

I am trying to find the electric field of a hollow, open-ended, thin-walled cylindrical conductor. I am trying to solve something regarding LINACs: Assume we have an isolated, hollow, open-ended, thin-walled cylindrical conductor, with a net charge. The net electric field within the...

Homework Statement The figure shows a cross section across a diameter of a long cylindrical conductor of radius a = 2.92 cm carrying uniform current 151 A. What is the magnitude of the current's magnetic field at the center of the conductor? Homework Equations Biot-Savart's Law The Attempt...

Homework Statement Homework Equations no equations required The Attempt at a Solution can someone please verify if my answer is correct. Thanks! I used the right-hand rule for the motor principle (although another tutor on physics forum told me that its supposed to be the 'left-hand rule'...

Homework Statement [/B] A 0.393 m long metal bar is pulled to the left by an applied force F. The bar rides on a parallel metal rails connected through a 42.9 ohm resistor as shown in the figure. So the apparatus makes a complete circuit. You can ignore the resistance of the bars and the rails...

Hi, I would like to know how to get the potential difference due to a constant local magnetic field acting on a wire moving at a constant speed perpendicular to the field. What is the link between F = q v ∧ B and the actual difference of potential in the circuit ? How to determine the induced...

A conductor with a large high frequency AC current causes a "Skin Effect" meaning that most of the current flows at the surface of the conductor. What does the skin effect look like if you have a conductor with one side flattened? And what does the resulting magnetic field look like? See...

If you drop a permanent magnet like steel through a copper tube it induces an emf, this is because you have a change in magnetic field/flux? But how? Why? The copper isn't producing a current before the magnet is dropped into it... Does something happen with the electrons in the copper?

Suppose there is a metal disk with an initial excess of charge represented by the four red electrons. Naturally, they reach their equilibrium position on the surface. After this, a new electron (the green one) is added exactly at the center. The repelling forces from the red charges cancel each...

We assume that there is no electric field inside the perfect conductor because relaxation time of metal is very short. whereas J=sigma*E But if this is the case, how can current flow inside the metal? -Is this because of battery? If there is a battery connected to a metal...

I just had a test question in my E&M class that asked what would happen to a conductor when placed in an external electric field. One of the "correct" answers was that all of the free electrons would move to the surface of the conductor. I understand that the free electrons would rearrange...

Homework Statement A conductor 7.5m long, is moved at a uniform speed at right angle to its length and to a uniform magnetic field. The density of the magnetic field is 0.64T. The emf generated in the conductor is 36V and the conductor is part of the closed circuit that has a resistance of...

Hi! I have to build a capacitor out of the following materials: 10 square feet of aluminum foil, 10 square feet of saran wrap (polyvinyl chloride), several sheets of paper, and tape to put it all together. I will only have about 30 minutes to manufacture my design. I have been researching...

Homework Statement Hey guys, I'm having trouble with a question covering magnectic field on a cilindrical conductor with a cilindrical cavity, here's the question: Consider a long cilindrical conductor with radius R1, with a cilindric cavity with radius a, in which R1>a. The axis of both...

Homework Statement EM wave with circular polarization travels in directon z interferes with perfect conducting surface xy. 1. find reflected wave 2. calculate induced charge density and surface current induced on conducting surface Can you verify if I started point 1. correctly, and give...

Homework Statement An infinitely long, cylindrical, conducting shell of inner radius b and outer radius c has a total charge Q. A line of uniform charge distribution Λ is placed along the axis of the shell. Using Gauss's Law and justifying each step, determine. A) The Electric Field for r>a...

Hello, If we have a solid conductor with all of its charge on its surface, and we then enclose some its charge with a gaussian surface that goes inside the solid conductor, will the part of the gaussian surface within the conductor have any electric flux? My textbook says it will have zero...

If a negatively charged Styrofoam plate is brought towards pieces of paper placed on an insulator (ex. a piece of paper), attraction occurs. Repulsion occurs if pieces of aluminum foil, which is a conductor, are placed on an insulator. What would occur if the pieces of paper and aluminum foil...

Why is the electric field just outside a conductor twice the field produced by a uniform sheet of charge? My textbook's explanation is that you can imagine that near a point P, the charge at the surface of a conductor looks like a small uniformly charged disk centered at P, giving an electric...

i have studied that a conductor is equipotential and charges don't flow through it but how does it flow through a wire?

A constant voltage V is applied at the two ends of a cable which is a perfect conductor (e.g. a superconductor). Since the cable, anyway, has a non zero inductance L, the current inside it is not infinite but it is proportional to time t: i(t) = V/L * t. In this situation, how much it is the...

Homework Statement If the diameter of a wire (conductor) is dimidiated , then its resistance: A Remains unchangable B is diminiated C Becomes two times greater D Becomes 4 times greater Homework Equations R=constant*length/Surface The Attempt at a Solution Cross sectional area=pi r^2=pi...

Homework Statement The resistance of a wire (conductor) in cylindrical form is: A Disproportional with the length of the wire (conductor) B Disproportional with the square of the wire (conductor) section C Proportional with the square of the length of the wire (conductor) D Proportional with...

Homework Statement A cylindrical conductor with a circular cross section has a radius a and a resistivity ρ and carries a constant current I. What is the flow of energy into the volume occupied by a length l of the conductor? Discuss why the energy dissipated in a current carrying conductor, due...

I have read this chapter about calculating internal and external inductance of a straight wire here. http://nptel.ac.in/courses/Webcourse-contents/IIT-KANPUR/power-system/chapter_1/1_4.html Seeing the flux linked with the conductor itself, emf due to that flux induced in upper half and lower...

bear with me, i know that this question has been asked many time , but i would like a definite answer, now, starting off the external charge density on the outer surface of sphere WILL be uniform by unique solution of Laplace equation and letting the sphere be huge, so, electric field due to...

I was reading through my College Physics text, and it talked about how NASA once swung a 20km long conductor through the Earth's magnetic field and setup a 3500V potential difference along the wire. I understand that there's no conventional current in that wire, it's not a circuit. But for a...

If you have two independent circuits, and then connect them at two points that are at arbitrary voltages by a single conductor, what happens to the system? A moment after the connection happens, I would assume there to be no current between the circuits since the two circuits would try and...

Homework Statement Determine the thermodynamic restrictions for a rigid heat conductor defined by the constitutive equations: \DeclareMathOperator{\grad}{grad}\psi = \hat{\psi}\left(\theta,\grad \theta, \grad \grad \theta\right) \\ \eta = \hat{\eta}\left(\theta,\grad \theta, \grad \grad...

Homework Statement [/B] "Demonstrate that the capacitance of a conductor is always smaller than or equal to that of a conductor which completely surrounds it." 2. Homework Equations /3. The Attempt at a Solution Solving this problem for concentric spherical conductors is easy enough, but I...

Homework Statement Homework Equations /The Attempt at a Solution[/B] I am trying to solve problem 2-13 from my textbook "Principles of Electrodynamics" (see image below). I believe that I should be solving the potential as \varphi(r,\theta) = \sum_{n=0}^\infty (A_n r^n +...

I know there is a pi phase shift when going from an area of lower index of refraction to higher. Is this phase shift still pi when going from a non-conducting dielectric with index of refraction n and reflection off a "good" conductor?

Homework Statement Find the potential at the centre and at P of a hollow uncharged conducting spherical shell if a charge q is placed at a distance of 2r from centre of shell. (r is the radius) Homework Equations All the charge induced on the sphere has to reside on the sphere's outer...

If there is a small object with positive charge placed above a metal plate, the object induces a negative charge on the surface of the plate facing the object. Let's call this surface as S1. (The metal plate is initially uncharged). But from conservation of charge, the net charge in a metal...

This seems like such a simple thing so maybe everyone can help me talk this through... So in a simple circuit with two conductors mated by physical means (think a plug into a socket) there will be heat because there is effectively arcing between the two conductors. So everyone keeps saying it...

I need some help with my science fair project question and I want to know what metal it is honestly it has to be copper write that is what wires are made of?

What gives it this property?

Peierls distortion states that for a 1 dimensional polymer (like polyacyteline) with lattice spacing a they should have a half-filled conduction band, why? And how does changing the lattice space to 2a cause it to form an energy gap? In my mind it should be the same as the first case...

I understand that there is no electric field inside a charged conductor, but; I don't understand why a connection to ground made on the inner surface of said sphere will flow current. Is this not correct?

If a conductor has a cavity in it and if a charge is placed in the cavity, then will the electric field inside it be zer