Wire Definition and 1000 Threads

Homework Statement An infinite wire carrying a constant current ##I## in the ##\hat{z}## direction is moving in the ##y## direction at a constant speed ##v##. Find the electric field, in the quasistatic approximation, at the instant the wire coincides with the ##z## axis. [Answer...

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >[/color] This problem is bugging me since a week so I decided to post this here Suppose we have a wire with some current 'I' and which at a point 'o' spreads radially in all direction along...

I am making an inductor coil out of wire that I removed from a piece of insulated copper wire. The inductor didn't conduct and I checked the conductivity of the coil alone via a multimeter and it didn't conduct any electricity and it is a copper wire so I need to know what is going on here...

Alright, so looking at how a 40-gauge wire being extremely thin and having high resistance(with respect to it's length), having an extremely short 40-gauge wire(about 1mm), it's possible to maintain 10A or possibly more? I know it's resistance is about 0.002 ohms, which is some what the same...

Homework Statement https://imagizer.imageshack.us/v2/935x701q90/540/k2taHx.jpg Homework EquationsThe Attempt at a Solution I think I got the idea to solve the B1 (the circular segment) and the ones that I wrote "zero", but I'm a bit confused on the straight ones (B2 and B3)... I'm using the...

The magnetic field that is oriented perpendicularly through a 9.2 cm diameter coil of wire drops from 6.4 T to 6.1 T in 0.076 seconds. What is the emf induced in the coil? Trying to answer this. My question is, if they are perpendicular then does that mean that cos90 makes phi = BAcos theta...

Homework Statement An infinite cylindrical wire of radius ##R## carries a current per unit area ##\vec{J}## which varies with the distance from the axis as ##J(s)=ks^2\hat{z}## for ##0<s<R## and zero otherwise where k is a constant. Find the magnetic field ##\vec{B(s)}## in all space. Homework...

Homework Statement This is a question on multiple coulomb scattering in a wire chamber momentum p = 500MeV/c wire resolution = 120 microns distance from wall to wire = 0.01m radiation length of wall material X_0 = 2E-3 m mass of charged particle m_{\pi} = 139.6 MeV/c^2 charge z = 1 How thick...

Homework Statement Long wire is bent such that it forms two parallel line segments that goes to -∞ along the z-axis and a semicircle of radius (R). Find magnetic field on Z axis. Homework Equations Biot-Savart Law (μ0/4π) I = ∫ dl' x R/ R^2 where dl' is element of length and R is the unit...

Homework Statement Find the maximum torque on a square shaped wire provided N=120; l=4cm;R=10##\Omega##; B=0.2 T ; ##\omega=200 revs/sec## Homework Equations ##\tau=IaBsin(\theta)## ##\epsilon=\frac{d}{dt}\Phi## The Attempt at a Solution ##i=\frac{\epsilon}{R}=-\frac{\frac{d}{dt} (BAcos\omega...

If a wire is neutral, and the electrons in it suddenly start to move, why is the wire still neutral? I would think that the electrons would contract causing the wire to be negatively charged.

Homework Statement In Fig. 29-71, a long circular pipe with outside radius R = 2.6 cm carries a (uniformly distributed) current i = 8.00 mA into the page.A wire runs parallel to the pipe at a distance of 3.00R from center to center. Find the (a) magnitude and (b) direction (into or out of the...

The electrical resistance of a wire varies directly with the length of the wire and inversely with the square of the diameter of the wire. If a wire 50 feet long and 2 millimeters in diameter has a resistance of 0.265 ohms, find the length of a wire of the same material whose resistance is 0.068...

Homework Statement A bar magnet is held above the center of a wire loop lying in the horizontal plane, as shown in the figure below. The south end of the magnet is toward the loop. After the magnet is dropped, what is true of the current in the resistor as viewed from above? (Select all that...

Can someone help explain why reflectometry is unavailable for diagnostics in a single wire? Or is it unavailable? I am a little confused as to why one could not use TDR on a single wire to find faults in the wire, such as nicks or corrosion... Is there a way to construct a model whereby this...

1. Wire 1 is oriented along the y-axis and carries a current I1. A rectangular loop located to the right of the wire in the xy-plane carries a current I2. Find the magnetic force exerted by wire 1 on the top wire of length b in the loop labeled "Wire 2" in the figure.2. F = IL x B 3. Attached...

Hi. In this video: he ignores the magnetic field from current 2(I2). Could anyone give me a good explanation why?

I'm learning about magnetism in my physics course, and we talked about Hans Christian Oersted's experiment where he observed electric current passing through a wire and analyzed the movement of a compass around this wire. He discovered that a magnetic field is generated by this current passing...

Stuff I'm wondering about: * can/does a conductors' cross-section influence inductive efficiency and/or directionality? * consider a 'wire' made from a dielectric material, with a conductive material evaporatively deposited on it's surface. if this wire were asymmetrical in section, e.g. it...

Hi there Is there anyone to help me about a definition of "DNA nano wire"?!

Hello fellow engineers! I am a student doing a simple course in Electrical Engineering. I've got an enquiry regarding this question " 1. In a three phase 4 wire system with phase to neutral voltage of 230V, a balanced set of resistive loads of 8 ohms are connected between each phase and...

Homework Statement A wire of length 1[m] vibrates with the base frequency which is 200[Hz]. the specific mass is 8[gr/cm3]. The maximal acceleration at the middle is 80,000[cm/sec2]. what is the amplitude Homework Equations Newton's second law: F=ma The cosine sentence: A^2=B^2+C^2-2BC\cdot...

Homework Statement 2 crosswise cosine waves of amplitude 2.5 cm and wavelength 5 cm are traveling in opposite directions in a wire with velocity 6 mm/s. draw graphs of the wire at times t=0, 2 and 4 sec. Homework Equations Waves propagating to the right: ##y=A\cos 2\pi \left(...

Hi! The question is simple, seemingly... Doubling the length of a wire, doubles the resistance of the wire... Why? There is one interesting point to it: Doubling the length of the wire also makes the ELECTRIC FIELD weaker TWO times. That automatically makes the current smaller two times...

I don't manage to get this task right. See the pictures. First i take point D and draw a free body diagram. Then i use the equation for equilibrium. I can then calculate the tension in the wires that goes from D to B and from D to C. I then take point B and draw a free body diagram, but all the...

Hello PF, I am having a bit of difficulty understanding this question. Homework Statement "A thin wire with linear charge density λ is surrounded by a conducting cylindrical shell." (There is a hollow cylinder with a wire though it) "If the electric field must be zero inside a conductor, is...

Problem Statement: Attached in pic. Find the tension between the wire of two charges. My attempt: So basically idk how to account for tension and thought you can just use the E-Force between the two charges in the direction towards the E-Field. How do i account for the tension? In which...

Happy to have any comments on this. Eric

When I connect filament(light bulb) in the electric circuit I can see the light. but when I connect only conducting wire(copper line) in the electric circuit I couldn't see the light from the conducting wire even though conducting wire less resistant than filament. How can I explain that...

Not necessarily a homework question but this is pretty fundamental. I can't get a decent derivation online. If the length of the wire in the uniform magnetic field is l and it moves a distance \delta s in \delta t: From the Lorentz Force Law: \vec{F} = q\vec{v}\times\vec{B} if flux...

Hey guys, I've been researching on the internet for some time, and can't seem to find what I'm looking for. I purchased solar powered single LED garden lights yesterday and am going to convert them to be able to plug into an outlet in the house. I've been reading some forums and everybody seems...

So I have earphones with a built in mic and the 3.5mm jack was broken so I cut the cable at the base where it meets the jack. And I have another 3.5mm headphone jack from some old headphones that has the wires for the built in miss as well. I was wondering which wires go together. On the...

I hope this is posted in the correct thread. When I was still in my physics class, we learned that a loop of wire with current can act as a self inductor. Just to refresh my memory: A loop of wire carrying current has a magnetic field around it due to current, however if the current changes...

The problem is :The conducting spheres (s1) of radius R and (s2) of radius 2R of the figure shown are connected by a thin wire. The conducting sphere (s3) of radius R is connected to ground. A charge Q is placed on the sphere (s1). 1- Determine the charges Q1,Q2,and Q3 thus distributed on the...

I have a harness with closed connectors (about 30 pins in each one of them),with about a dozen of twisted shielded wires. need to mark them to know which one is which. Tried to connect a needed pair to a ac power supply and find a wire with ac sensor, but on the low voltage shield blocks the...

Hello! I want to induce a (weak) signal in a wire across the room from me. I was just wondering, how would I go about doing this if I couldn't touch the wire and couldn't modify the equipment to accept these signals BUT was close and in line of site of the wire?

Homework Statement I am currently doing the phy project on length vs resistance of wire. to reduce the power loss in transmission wire, the length of wire must be short, as power loss = (I^2) R... in my experiment , I fixed I (current) , now i am asked to find the application of low...

I have some questions about electrons flow. 1)Lets say we have a simple circuit with a metal wire and a battery supplier.Firstly if we can imagine an electrons flow in a conductive material like metal but with zero resistance and no atoms for the electrons to collide , the Fc1 force from the...

two wires A and B made from two different materials have temperature coefficient of resistance equal to 0.0025 and 0.0005 ohm per degree Celsius respectively. It is desired to make a coil of wire having a resistance of 1200 ohms with a temperature coefficient of 0.001, using a suitable length of...

Homework Statement There are two wires: Wire one looks like --=========-- Wire two looks like --------------- Do they have the same resistance? So this isn't actually one of my homework problems, but I'm just debating this with a friend and neither of us can come to an agreement. So...

Why is it that the width of a wire grid polarizer has to be less than the wavelength of the wave which I want to polarize? What would happen if the width was a little bit more?

Hi everyone, I have a 12mm long hard ferrite core that I want to use as an electromagnet. I have wound it with 0.8mm copper as tightly as I can by hand, in a single layer, but the field is not strong enough. I have placed another coil over that first coil, and then a third coil, each in...

Will the tension at various points of a wire rope remain same when subjected to tension? for example let us assume that a wire rope is pretensioned and held between to fixed supports .So will the tension remain the same at the center and either of the anchorage points.

I am working on impedance measurements of close-wound electromagnetic coils. I am using an Agilent LCR meter to measure the impedance of these coils over a frequency range of 20Hz-2MHz. When I perform the measurements, I get impedance magnitude and phase angle in degrees. I would like to...

Hello. I'm floundering. What is the right way to formulate a problem of calculating the current density distribution across the wire's cross-setion, taking into account eddy currents? If the Maxwell's equations are not the way to go, what is? What should be the boundary conditions or any...

Homework Statement The resistivity of gold is 2.44 x 10-8 Ω m at a temperature of 20°C. A gold wire, 0.5 mm in diameter and 44 cm long, carries a current of 380 ma. The number of electrons per second passing a given cross section of the wire, is closest to: A) 2.4 × 10^18 B)...

I've recently read that the electrons move relatively slowly to what I had previously thought through a metal. That the "drift velocity" is slow, but because the electrons are plentiful, they can pass down the signal very fast. Near light speeds. Could someone explain what I'm missing and this...

So, I've got a wire with a semicircle about the origin, my task is to find the magnetic field at M=(0,0,z). I want to use Biot-Savart, so I find dl', r and r-hat. (r being the vector from the source point to field point) \begin{equation} r^{2}=R^{2}+z^{2}\\...

Homework Statement You have a loop of wire (dimensions c and d) which is oriented vertically on the y-axis (the y-axis splits the rectangle in two equal pieces), and rotates about the y-axis at constant angular ##\omega##. The magnetic field is in the +i direction. What would be the torqque...

There are two sphere of radius a and b and they are connected by conducting wire. Then why the electric potential becomes same of both the sphere?