Wire Definition and 1000 Threads

Homework Statement A long wire carries a current i uniformly distributed over a cross section of the wire. Show that the magnetic energy of a length l equals μ_0 i2 l / 16π. Describe why this doesn't depend on diameter. Show that the inductance for a length of the wire l associated with the...

consider a horizontal cylindrical tube of cross sectional area A fitted with two frictionless pistons. The piston are connected to each other by an inextensible wire. Initially, the temperature of the gas is To and its pressure is Po which equals the atmospheric pressure. Find the tension in the...

Hey Guys - Long time reader, first time poster. I am attempting to develop a prototype of a new product. Part of this product will involve a good length of resitive wire that will generate heat. To accomplish this I cannibalized an electric blanket for the resistive wire and power controller...

Hey all, First post, thanks in advance for any help. I see there is a lot of discussion on this site and others about nichrome heating elements. I apologize if my question is very similar to others, but I have not exactly been able to figure out what I need to learn/lookup to answer my...

Homework Statement A very long u-shape conducting wire is placed vertically in a constant magnetic field. The magnetic field is perpendicular to the plane of the wire. The strength of the magnetic field is B = 0.9 tesla. A conducting rod is placed on the wire, as shown in the picture. The...

Homework Statement Consider that the electric field is proportional to q r-2-d\hat{r}, where q is magnitude of a point charge and d<<1. Two concentric conducting esferical shells for radii a and b (a>b) connected by thin wire. The external shell has a total charge qa. Prove that the charge...

A 1.80-m long round steel wire with a cross-sectional diameter of 0.80 mm is placed over a light frictionless pulley, with one end of the wire connected to a 23.0-kg mass and the other end connected to a 14.0-kg mass. By how much does the wire stretch when the masses are in motion? S= F/A e=...

Homework Statement An infinite wire of parabolic shape carries a current I, find the magnetic flux density B, at the focus Homework Equations B=(μ0*I)\(2∏r) I know this is for a straight wire, I'm not sure what i would use for a U shaped wire The Attempt at a Solution Well I figure...

1. Homework Statement [/b] A solid cylindrical conducting shell of inner radius a = 4.9 cm and outer radius b = 6.1 cm has its axis aligned with the z-axis as shown. It carries a uniformly distributed current I2 = 7.4 A in the positive z-direction. An inifinte conducting wire is located along...

Hello there, I am having a real stupid moment. In the space XYZ, a long wire is along the Y axis and is submitted to an alternating current I_{0}\sin \omega t. I am trying to establish the equations for the B(t) and E(t) fields along the X axis. I assume that the distance to the cable...

Homework Statement Hey all, I am studying for the GRE and I need help with this question: A rectangular loop of wire with dimensions shown above (see attachment) is coplanar with a long wire carrying current I. The distance between the wire and the left side of the loop is r. The loop is...

At the edges of a very long current-carrying wire, the magnetic field is not the same as in the middle, right? And integrating biot-savart's law in the edge-region of the wire will make it possible to calculate this field-strength, right?

If we consider the common electromagnet that is made by passing current through a wire coiled around an iron core, I wonder what effect produces more magnetic field: 1. The field produced outside the solenoid due to the current in the wire 2. For this effect I don't insist that the object is...

Homework Statement A wire loop of area 2·0×10−4 m2 contains 40 turns, and has a total resistance of 40Ω. The plane of the loop is perpendicular to a uniform magnetic field of magnitude B0. The magnetic field is now turned off such that the flux through the loop drops linearly to zero. A total...

Homework Statement Calculate the inductance (SI units: Henries) of a coil of wire having a loop diameter of 0.5 cm and coil length of 10 cm. The wire has 1000 loops per meter. Homework Equations I think I can use this equation: L= μₒAN² / x, x = length of wire, μₒ = 4π*10^-7 Tm/A A...

In the top circuit, electricity doesn't flow through section 2, but it does in section 1. In the bottom circuit however, electricity flows through both sections 3 and 4. Why does simply adding a resistor stop the flow of electricity in 2? Much appreciated!

Homework Statement Two conduction spheres with radius R1 og R2 are connected with a conducting wire. The length difference between the spheres is large enough to neglect any effect their respective electric fields have on each other. The total charge of the system is Q. Find the charges...

Homework Statement Consider a string that admits waves with velocity v. Near the origin, i.e. in the interval -a < z < a, the string has a different weight, and as a result a different propagation velocity u. The amplitude of the reflected and transmitted wave are proportional to the amplitude...

Homework Statement Suppose you wish to fabricate a uniform wire from 2.00 g of copper. The wire is to have a resistance of* R = 0.480 Ω*and all the copper is to be used. Homework Equations The Attempt at a Solution In the problem, they suggest using this relationship for...

In each of parts (a), (b), and (c) of the figure below, find the direction of the current in the wire that would produce a magnetic field directed as shown. part (a) right to left part (b) out of the page part (c) lower left to upper right Ughhhhh So, the right hand rule...

Lets say we have an infinite charged wire with a line charge \lambda on it. Now when I move with respect to this wire the E field will increase do to length contraction. And there will also be a B field that we could calculate with ampere's law. But the increased E would make it seem...

Homework Statement (a) The current through a wire is a steady 2.5 amps. How much current passes through it between t = 0 seconds and t = 4 × 10^-4 seconds? For this one I thought it would be 2.5( 4 × 10^-4), but it says how much current and I thought current was a rate. So what does the...

Homework Statement A long hairpin is formed by bending an infinitely long wire, as shown. If a current of 1.20 A is set up in the wire, what is the magnitude of the magnetic field at the point a? Assume R = 3.20 cm...

Homework Statement a) What is the current contained in the cylindrical shell of wire defined by R/2<r<R? b) What is the total current running through the wire? c) Given your answer to (b) what potential difference V must be applied between the ends of the wire? Homework Equations...

Homework Statement A long thing wire carries a current of 2.0A. An electron of charge -1.6x10^-19 moves parallel to the wire at a distance, d of 0.01m The electron velocity is 100km/s. State the magnitude & direction of the force acting on the electron.Homework Equations Hmmm! Not really sure...

Homework Statement Suppose a very long straight wire were held perpendicular to the plane of the page such that it intersects the page at point D. Additionally, suppose the wire was being moved toward the top of the page. Suppose instead that the wire were moved toward the left side of the...

Homework Statement There are two wires in parallel with the current traveling to the left in both. Find the direction of the torque on the top wire due to the bottom wire. Homework Equations torque=μ×B The Attempt at a Solution I know I can use the right hand rule to find the...

Essentially I have been given five resistors of strength 180 kΩ, 220 kΩ, 270 kΩ, 330 kΩ, and 390 kΩ and have been told to devise a way to wire these to produce a total resistance of exactly 206.421 kΩ. I have been working on this simply using a guess and check method and have had no luck...

Homework Statement A copper wire of diameter d carries a current density at the Earth’s equator where the Earth’s magnetic field is horizontal, points north, and has magnitude 5.yz × 10^-5 T . The wire lies in a plane that is parallel to the surface of the Earth and is oriented in the east...

Homework Statement Problem: Determine an expression for the magnitude of the magnetic force on a charged particle moving near an infinitely long wire, carrying a current i. Particle with charge q Magnitude of the particles velocity = |v| Magnetic field strength = B Current = i Homework...

Hi everyone, I am trying to find the mean free time between collisions for free electrons in a copper wire given the dimensions of the wire and the resistance, electron density and temperature. I figured I needed to find the conductivity, plug that into an expression for mean free path...

Homework Statement A rectangular coil has 120 turns of wire and is of dimensions 10 cm by 15 cm. The coil is placed in a uniform magnetic field B= 2.6 T such that the field lines make an angle of 33 degrees with the direction normal to the coil. Calculate the magnitude of the torque on the...

Homework Statement A charge per unit length +λ is uniformly distributed along the positive y-axis from y = 0 to y = +a. A charge per unit length −λ is uniformly distributed along the negative y-axis from y = 0 to y = −a. Write an expression for the electric field at a point on the x-axis a...

in household supply, one wire is neutral wire and another is ground. Both are at 0 potential. My question is that can we interchange both wire. I mean use live wire with ground?

Homework Statement I solved this problem. I just have a general question at the very end. A current flows in a wire that has straight sections on either side of a semicircular loop of radius b. Find the mag and direction of the magnetic field B at point P(center of loop). ......... periods =...

I'm trying to make ferrofluid according to this guide: http://www.sci-spot.com/Chemistry/liqimag.htm and in step 5 I need to heat the solution to near boiling but I don't have access to a bunsen burner or heating plate. Also I can't do this in the kitchen because this heating is to remove...

how do i wire this disk with the detectors

A cylinder (800 N) is beng kept up by the the poles. Find the Foces in A and B and the tension in the wire I have a bit unusual statics problem. Never done a problem simular to this. I know about Fx=0 and Fy=0 and the moments at any point is=0 Can anyone help me to get started...

Homework Statement I'm attempting to solve the constants that are attained after using separation of variables for a solid permeable prolate spheroidal core wrapped with N turns of wire using boundary conditions. H^{1}_{\delta} inside core H^{2}_{\delta} insulation H^{3}_{\delta}...

Homework Statement Two metallic spheres have radii of 19.1 cm and 11.5 cm, respectively. The magnitude of the electric field on the surface of each sphere is 3490 V/m. The two spheres are then connected by a long, thin metal wire. a) Determine the magnitude of the electric field on the...

looking for standards & guidelines on Neutral Wire for distribution system, especially Neutral Up or Neutral High (neutral on top of the phase conductors), advantages & dis-advantages of it.

Homework Statement I have a wire of some resistance, resistivity, and length. What is the maximum error in measuring the diameter that you can have if the resistance is to have 1% uncertainty? Homework Equations R = \frac{ρ*l}{\pi*r^{2}} for which I substituted the area as \pi(.5...

Homework Statement An aluminum wire of length l1 = 60cm, cross section area 1.00 x 10-2cm2, and density 2.60g/cm3, is joined to a steel wire of density 7.8g/cm3 and same cross sectional area. The compound wire loaded with a block of mass m = 10kg is arranged as shown so that the distance...

So does a wire actually have a magnetic north and south pole? I know a coil of wire will form one but a straight wire will only attract another wire if the other wire's current is going in the opposite direction and repel if in the same direction. I have looked for images and they always just...

Homework Statement Let's say there's a uniform circular wire with radius r. There is a uniform force pushing outward from the center in all directions of the wire. This total force is 10N. What is the tension in the wire? Homework Equations N/A The Attempt at a Solution Let's say the...

If we use the right hand rule, we see that a hole current, or positive ion flow, creates a magnetic field around the wire where the flux moves in a clockwise direction. Counteractively, electron flow through a wire produces a magnetic flux that flows counterclockwise over the wire. Three...

wrap a wire around a cone [urgent] Hello everyone, i need help solving a problem I'm facing so i can continue my project. So the problem I'm facing is that i got a cone 60cm height and 45 cm base diametre, and i want to wrap a wire with (0,3±0,1)cm diametre around the cone, but i must do it in...

Homework Statement This is the problem 10.10 in Griffiths' Introduction to Electrodynamics, 3e (See attached image) I am only concerned about finding the retarded vector potential \textbf{A} Homework Equations \textbf{A}(r',t) = \frac{\mu_{0}}{4\pi} \int \frac{...

Hello everyone, I was wondering how to calculate the added resistance experienced when a cable is coiled rather than layed flat due to the magnetoresistance of the magnetic field created by the solenoid configuration. I will be running 250A though a cable which will be coiled like a...

I have a motor that I am using, and I need to know what gauge wire to use to connect to the motor. I've looked all over online, but haven't found anything that can tell me a formula or anything to use to figure this out. The motor is 24VDC and draws 50A max, and would be running about 15...