Conductor Definition and 790 Threads

In the Wikipedia page of the moving magnet and conductor problem, it asserts "This results in: E' = v x B", but does not elaborate why. What's the full derivation?

Homework Statement A conductor sphere of radius R without charge is floating half-submerged in a liquid with dielectric constant ##\epsilon_{liquid}=\epsilon## and density ##\rho_l##. The upper air can be considered to have a dielectric constant ##\epsilon_{air}=1##. Now an infinitesimal...

I'm interested in the following general question: Assume x,y,z is an axes system, and that the y-z plane is occupied by a conductive plate at a known potential V with respect to the earth. Now, a conductive material M of neutral global electrical charge is placed at some distance of the plate...

Homework Statement A charged rod of charge 'q' is at a distance 'd' from a perfect conductor as shown below. What's the total surface charge on the conductor? 2. Homework Equations I tried to solve this without equations. The Attempt at a Solution [/B] Basically, as long as there is E field...

We know that skin depth in a conductor is found using the following expression, (Credits: http://farside.ph.utexas.edu/teaching/315/Waves/node65.html) Basically, as the wave propagates in a conductor, it's electric field strength reduces and reaches 1/e of it's initial value at the skin depth...

The figure shows a charge q1 exerting a force on a test charge qu. What happens to the electric force when a conductor is placed between q1 and qu (cases 1 and 2)? Does the force still remains the same? I am asking this because I am actually interested in finding what happens to the flux in...

Homework Statement One of the two glass panes in each window is coated with a transparent electrical conductor. Why does this coating improve the window's insulating ability? Select one: a. The transparent conductor is black in the infrared, with a low-temperature emissivity of almost 1. b...

Hi, I thought that I understood why, once the free charges stop moving, ##E=0## inside a conductor, but I really don't. Can someone please help me out? I've heard the following arguments, but I don't think I understand any of them: I don't think ##q=0## implies ##\vec{E}=0##. I understand that...

In the textbook (attached image) it says that the boundary condition is V=0 at r=R. This creates a correlation that ##B_l=-A_l R^{2l+1}## but the potential at any boundary is continuous so when we take this account, we get. ##B_l=A_l R^{2l+1}## These two clearly contradict each other. I'd...

So in my textbook (Introduction to Electrodynamics by Griffiths) it said that inside a conductor, the electric field E would have to zero, since if it wasn't the free charges would move accordingly and create a electric field that cancels the original field. But in a question that soon followed...

If I have 120 vac power cord and I wrap a coil around one of the conductors, will a current/voltage be produced in the coil? If so what are the equations that could be used to characterize this arrangement? I.e., how many coils, what size wire, etc. To produce a certain voltage in the coil?

if a random electron strikes a neutral conductor does it get absorbed and increase the voltage of the conductor

Hi, Is it true that the transmission of energy is not inside an electrical conductor, but outside the metal. this even for frequencies around 50 hertz. Thank's

Homework Statement This is the exercise 10.6 from Feynman lectures on Physics 2. Two coaxial pipes of radii a and b(a<b) are lowered vertically into an oil bath. If a voltage V is applied between the pipes, show that the oil rises a height H. Show that H=(V^2)(κ-1)ε_0/[ln(b/a)ρ(b^2-a^2)g] where...

suppose there is a cavity inside a current carrying conductor.if anyone is inside the cavity he will be electrified or not?what's the explanation of this problem?

If I have a box evacuated of air with 5 of the sides mirors and one side a heat conductor. will the photon gas inside have photons that get absorbed by the heat conductor and re-emitted when the photons strike the heat conductor

Homework Statement consider two concentric shells, the smaller one has inner and outer radius a and b, the larger one has IR and O.R. c and d. Inner shell has total charge -2q and outer shell has total charge +4q. NOTE-This is a random situation I created to explain my doubt properly, so we...

Background: an ordinary wire supports an external radial electric field proportional to voltage, and an internal axial field equal to current times resistance per unit length. The present question is whether the internal axial field has an external counterpart. The original question that...

Homework Statement Consider a thin conducting shell of radius r carrying total charge q. Two point charges q and 2q are placed on the points A and B which are at the distances 0.5r and 2r from centre of the shell respectively. If the shell is earthed how much charge flows from to the earth...

1. Homework Statement Hello, I'm learning electricity and I'm having a few conceptual questions regarding the subject ( especially about neutral objects ) which I'm unsure of the answers and I'd be happy if someone could help me:1. Is the charge density of a neutral object ( doesn't matter if...

Homework Statement So I came across with following problem: > Consider a cylindrical conductor of infinite length and circular section of radius a and that is traversed by a stationary current I. What is the magnetic energy stored in the conductor. Homework Equations 3. The Attempt at a...

I have a question with regard to split single phase (in United States) electricity. I understand that there are 2 hot legs each 180 degrees out of phase at +120v and -120v (240v between hot legs) going from transformer to breaker box and a center tapped neutral Earth bonded wire at 0v with...

Homework Statement Find the admissible current density Jadm for a wire that has no insulation and also for a wire that has two layers of insulation and compare it to Jadm for the case when the wire has only one layer of insulation.2. The attempt at a solution and equations In the image I've...

I have a question in my book and it’s confusing me a bit. I tried to search online for similar solved problems but couldn’t succeed. So here it goes:Calculate the induced EMF in a conductor loop when the angle between \vec{A} ~ and~ \vec{B} ~is~ changed ~from ~{0 °}~ to ~{α °} in 1 second...

The electric field inside a conductor is zero. Or: the internal electric field is equal in magnitude but opposite in direction to the external electric field, so that the net electric field inside the conductor is zero. Why is this? The part where I am confused is why the magnitude is equal...

Homework Statement Homework Equations Emf=B l V V is (velocity) F=QVB The Attempt at a Solution Emf=BLV Work=QBLV Force=BLV how come V=Q/m. its not possible or is it?

In my lab we are working with a Coaxial coil and stainless steel tube, and are aiming to find the mutual Inductance. I've done some looking around and have easily found the Inductance of a Coaxial cable, and for that of Coaxial coils, but am having trouble with a combination of the two. The...

The electric field inside of a conductor is 0, but what exactly does inside a conductor mean? It’s easy enough to understand what this means if the conductor is closed, but what if the conductor is open in some way? What counts as inside and what doesn’t?

Does static charge near to a constant current carrying conductor experience force on it? I am asking this question because i have learned that electric field and mangnetic field are same thing but viewing differently with respect to the frame of reference...when a positive test charge moves (...

Homework Statement I am confused if whether the collisions in a conductor is because as the electric field pushes electrons through the material, they literally bump into the orbitals of the atoms because these atoms get in the way of the electron flow, or whether these collisions happen...

If I had metal stripe significantly longer than the wavelength but less wide than one wavelength and it would be at an angle in the plane perpendicular the length of the stripe to to the incoming wave, would itireflect specurarly or diffusely?

My question is basically similar to a thread that was posted 12 years ago: https://www.physicsforums.com/threads/electrons-flying-off-a-conductor.119269/ I was glad to see that there was already a thread which asked my question in the forum. But when I read through all of the discussion, I don't...

Hi I have attached a picture here, of a solenoid with a copper block connected to a battery suspended in it. The current moving is clockwise, So the magnetic poles would be as shown. Now my problem always is this, I get so confused with this, I used Fleming's left hand rule to find the...

I'm having trouble seeing how electric potential energy production on a conductor follows conservation of energy. Let's use the photoelectric effect as an example. A photon with energy E = hν strikes a conductor, ejecting a photoelectron with a maximum kinetic energy of hν - φ. Assuming the...

Need two transparent conductors in an arrangment like this on a transparent plastic film. Such as ITO on PET. But it doesn't have to be ITO necessarily. There are going to be much more fingers and size of the lanes and their gaps are going to be sub milimeter, so hand drawing is out of the...

Does a rotating conductor generate an electrical potential due to charges "feeling" a centrifugal force?

Homework Statement There is a conductor with the square-shaped area. the Radii are r1 , r2 with width b and resistivity ## \rho_R##. Find the resistance R between A and B 2. Homework Equations ##I = \iint_A\vec J \cdot d \vec A## ## \vec J = \kappa \vec E ## ## \vec E = \rho \vec J## ## V =...

I was watching this video of veritasium today and was wondering why the aluminum plate doesn't oscillate when there is a changing magnetic flux. When the flux is increasing, the induced magnetic field (by the induced current) is against the magnetic field of the coil and this acts like 2 north...

Homework Statement If I have two current carrying conductor carrying current is same direction, they move towards each other so kinetiisc energy increases. So which force does work here? Homework EquationsThe Attempt at a Solution I know magnetic force can't do work, is work done by some...

Homework Statement I am trying to figur out whether there is or isn t an Electric Field along the surface of a cylindrical current carrying wire With radius r and length L, current I and resistance R. I was trying to see if someone already asked this and i found one discussion, however where a...

I am interested can you please point out, are there any ion conductors (electrolytes i assume they are called) that are comparable in their resistance to copper at room temperature? I am thinking about both liquid or solid conductors here. Also I was wondering is it possible to make continuity...

If an AA battery were placed in some kind of ideal conducting 'ether': 1) Would current flow, and if so, what would the flow of electrons look like? 2) How would the magnetic field look? (I imagine that if there was an electric current flowing, that the magnetic field would look a little like...

I’ve looked at the answers given to the previous times this question has been asked, but I still don’t seem to understand how this holds in the case of a closed circuit. Here’s an explanation given before: “Think of the wire as a horizontal cylinder. If you apply an electric field pointing to...

Homework Statement Homework EquationsThe Attempt at a Solution Since the dependence of resistance upon the tem. is different for metal and semi - conductor ( increase of tem. decreases semi - con. resistivity while increases metal's resistivity.), option c is not the right answer. Since...

Consider a parallel plate capacitor formed by two plates of length ##L## and width ##d##, separated by a distance ##e##. There is a vacuum in between the plates. Let's note the capacitance of this arrangement ##C_0##. I insert a conducting plate of length ##l=L/2##, with ##D##, and thickness...

Homework Statement Consider a spherical conducting shell with inner radius R2 and outer radius R3, that has other spherical conductor inside it with radius R1 (this one is solid). Initially the 2 spheres are connected by a wire. We put a positive charge Q on the sphere and after some time we...

I have Semiconductor at my home. I had to use a Semiconductor as junction of electrical current. Current at the junction could be so big if I shoot a sun light from lens and mirror to a Semiconductor. What happen about my experiment? What is it a fotoelectric effect?

I'm reading through my soil heat flux chapter and I have two questions: it seems that 1. Cs (volumetric heat capacity) in soil increases with increasing soil moisture. I assume volumetric heat capacity is the amount of J it takes to heat up a volume with 1 degree. Does that mean that the more...

Ok, this might be a really dumb question, but I still am asking it: I was reading about gauss' Law when it comes to a hollow conductor with a (say) point charge inside it, and it seems intuitive to me that, in electrostatic equilibrium, the charges rearrange themselves to cancel the electric...

Hi, I recently came across the familiar image of a metal sphere in an electric field: https://i.stack.imgur.com/x58Ia.jpg I noted how the free-charges on the surface of the sphere align with the electric field lines as opposite charges are attracted. Then I wondered, 'what if the sphere was...