Wires Definition and 543 Threads

  1. Whovian

    Two wires with current - would this be correct?

    While chatting with a friend, I came up with something to think about, being, "if two parallel wires, with constant and equal current wrt position, are put next to each other, the charges in the wires can exert normal forces on the wires, and they're left at rest wrt one another to interact...
  2. Saitama

    Flux due to infinite long wires

    Homework Statement Twelve infinite long wires of uniform linear charge density (λ) are passing along the twelve edges of a cube. Find electric flux through any face of cube. (see attachment)Homework Equations The Attempt at a Solution I have actually solved the problem but I think there's a...
  3. M

    Force between perpendicular wires in the same plane

    Homework Statement I was just wondering, so let's say there are two current carrying wires in the same plane that are perpendicular. One of them is infinite length, the other is a wire segment some distance away from the first one and perpendicular to it. What's the force on the wire...
  4. A

    Magnetic field at P, between six parallel wires.

    Homework Statement Six infinitely long parallel wires, each carrying current +I in z direction, perpendicular to the (x, y) plane. They are spaced at angles 2pi/7 around a circle of radius d. A seventh wire, which would make the arrangement symmetric, is missing. What is the magnitude and...
  5. E

    Engineering In circuit analysis, is current through wires defined?

    Homework Statement This is not a homework problem, but related to my circuits class. In the typical electrical engineering simplification, the resistance of wires in the circuit is taken to be 0 Ω. Also, the potential difference between two points along the same wire is 0 Volts. Does...
  6. B

    Power loss in connectors and wires

    Hello, I'm working on a project at which a large amount of current is being passed through a low voltage system (48 Volts). In one part of the system, there are connectors rated at 12 Volts in which the 48 volt DC current is passed through. How much power loss might I be suffering here...
  7. Z

    Tension: 2 wires one at 60degrees one at 45degrees

    How do you solve for tension, is there a general formula to use for emample such as this problem(this is not homework, its an example i saw ) you have 2 wires one at 60degrees one at 45degrees both wires have a weight of 5N. find the weight of the third wire that's going down? how does...
  8. K

    Why Doesn't a Synchronous Machine Induce EMF in DC Field Wires?

    conflict: why synchronous machine doesn't produce induced EMF in the DC field wires Isn't it current path through winding which produce magnetic field (rotating) the must produce EMF in the dc winding of field (same theory of induction) but why isn't true in synchronous
  9. R

    Magnetic Field with three parallel wires

    Homework Statement Three long, straight wires are carrying currents that have the same magnitude. In C the current is opposite to that in A and B. The wires are equally spaced. Each wire experiences a net force due to the other two wires. Which wire experiences a net force that has the...
  10. B

    Resistance between parallel wires in an insulator?

    Hi all, New here...I was wondering if anyone knows a formula to calculate the (insulation) resistance between two parallel conductors buried in an insulator. For example say 2 copper pins of 1mm diameter spaced 2mm apart over a 20mm length in a plastic (ptfe). The numbers/material are not...
  11. B

    Finding force on a pole held by wires using vectors

    Here's a vector tent problem with the solution. Can someone please explain it to me. https://docs.google.com/open?id=0B7WWo1BlPRXKSTU5WGRLZ2NaX2c
  12. Z

    Condition +-.1v from 2 wires to 0-5 for Arduino analog

    I am toying around with connecting a 236PC 15GW pressure sensor to my arduino board. I am supplying nearly 10 volts to the Sensor and can get +- .1V readings from some simple tests. How do I condition these two lines that give +- .1V to range from 0-5 Volts for the Arduino analog pins.
  13. C

    Deriving Relationships for C_P - C_V & C_F - C_L in Stretched Wires

    Homework Statement I have been stuck on the following question for a while now, particularly part B and C, and I'd like some help with it please. I've completed part A already. The Question: (A) Combine the following TdS equations: TdS = C_{v} dT + T\left(\frac{\partial P}{\partial...
  14. D

    Magnetic field between 2 parallel wires

    Homework Statement Sorry. I know this question is on the forum somewhere, but I still don't get it... Thus. For parallel wires, at the mid-point of the wires, what is the strength of the magnetic field? Do I use the formula B=\frac{μi_{1}i_{2}L}{2∏r}, or is it the sum of B=\frac{μi}{2∏r}...
  15. P

    Finding magnetic field from two crossing wires

    Homework Statement Two insulated wires in the x-y plane cross at a 30° angle but do not make electrical contact. Each wire carries 3.0 A current (the angle between current directions is 30°). Find magnetic field in two non-equivalent points located 4.0 cm from the intersection, in the x-y...
  16. G

    AC Current in unconnected wires

    Hello, My electrician had to disconnect the ground wire from mains distribution box a day ago. And he forgot to attach it back. I did not know it was un-attached. Then in the evening, I touched my computer and got a shock. I used a screw driver type phase tester and checked the ground part of...
  17. E

    Electric Field inside wires of Circuit?

    Homework Statement This is not a homework problem but I only have permission to post here because I am new. My question is about the electric field in the wires of a simple circuit with a battery and a resistor. Electrons from from lower potential to higher potential terminal battery, meaning...
  18. N

    Magnetic field from four parallel wires

    Homework Statement Hi I am looking at four parallel wires of finite length L, whose currents run in the directions shown in the attached figure. There is no gradient along the wire-axis, so from Maxwell's equation \frac{dB_x}{dx} = -\frac{dB_y}{dy} \equiv \tilde B. In order to find an...
  19. S

    Magnetic Field at a point due to two parallel wires

    Homework Statement Two long parallel wires are a center-to-center distance of 4.90 cm apart and carry equal anti-parallel currents of 3.70 A. Find the magnetic field intensity at the point P which is equidistant from the wires. (R = 10.00 cm)...
  20. M

    Net force on 3 parallel wires carrying current.

    Homework Statement You are given 3 wires parallel to each other (1)------> I (2)<-------I (3)------->I http://www.webassign.net/knight/p32-38alt1.gif (not sure it this link works) I1=I2=I3 = 16A the distance between the wires is d=2cm length of the wires is l= 50cm Homework Equations I...
  21. J

    Question about conductors, wires and lattice of ions

    Hi guys, sorry as this is probably a silly question. This isn't homework, but it's something I'm confused about in my GCSE course. If a lattice of ions can't conduct electricity when solid, then why can a wire (composed of these lattices (I think?)) conduct electricity? The electrons in a...
  22. J

    Magnetic Field given two wires

    Homework Statement A long pair of insulated wires serves to conduct 29 A of dc current to and from an instrument. (a) If the wires are of negligible diameter but are 2.8 mm apart, what is the magnetic field 10 cm from their midpoint, in their plane (see figure)...
  23. P

    Force between Two Current-Carrying Wires

    Hi, I always had difficulty with understanding how to determine whether the force between two current-carrying wires is attractive or repulsive. I know that if the currents are traveling in the same direction the force is attractive and repulsive if the currents are traveling in opposite...
  24. R

    Finding tension of 2 wires at different angles

    A bag of cement of weight 325N hangs from 3 wires as shown in figure (I've attached it). Two of the wires make angle1=60oand angle2=25o with the horizontal. If the system is in equilibrium, determine the tensions of T1, T2, and T3 If you can't see the image, the T1 and T2 are suspended from a...
  25. N

    How to Find the Magnetic Field Gradient from Four Parallel Wires?

    Homework Statement Hi I am looking at four parallel wires of finite length L, whose currents run in the directions shown in the attached figure. There is no gradient along the wire-axis, so from Maxwell's equation \frac{dB_x}{dx} = -\frac{dB_y}{dy} \equiv \tilde B. How would I go...
  26. N

    Relationship between power dissipation in wires and temperature

    Hello, I am wondering if anyone knows any correlations or equations that can give me the temperature of a wire due to power losses. I understand how to calculate the power loss in the wire, based on wire resistance and current (P=I^2*R) but how do I turn this into a heat transfer problem and...
  27. P

    Faraday's Law of Induction - Current in Multiple Wires

    Homework Statement A 7.40 cm diameter coil consists of 15 turns of circular copper wire 2.3 mm in diameter. A uniform magnetic field, perpendicular to the plane of the coil, changes at a rate of 7.29×10^−3 T/s . Determine the current in the loop. Express your answer using two significant...
  28. P

    Calculating a Magnetic Force Concerning Paralell Wires

    Homework Statement Three long parallel wires are 3.8 cm from one another. (Looking along them, they are at three corners of an equilateral triangle.) The current in each wire is 5.30 A , but its direction in wire M is opposite to that in wires N and P (see the figure). 1. Determine the...
  29. W

    How electricity moves through wires

    Can electrical currents in a wire affect each other? Imagine racecars and how they affect each other in a race for this. Reply in simple english please.
  30. B

    What wires should I use for my HV PSU and lifter project?

    Hi, I am currently working on a personal project, I am trying to build a lifter (ionocraft) According to the book my HV PSU. will give around 25 - 30 kV. I already got all the parts for the circuit, I just have a couple of questions about wires: how do I choose a wire? should I use...
  31. S

    Magnetic Forces Between Current Carrying Wires

    In each of the 10 cases below, 2 - 4 Very long straight wires are parallel to each other. Rank the strength of the total magnetic force on each of the labeled wires. So each case has 2-4 wires with varying currents and distances between; I have to calculate the magnetic force and then rank...
  32. S

    Find the Current using Force/Length Between Two Wires

    Homework Statement Two long parallel wires are separated by .006 m. The current in one of the wires is twice the other current. If the magnitude of the force on a 3m length of one of the wires is equal to 8μN, what is the greater of the two currents? The answer: .40 A Homework Equations...
  33. F

    Infinite Parallel wires Magnetic field

    Homework Statement Two long parallel wires each carry a current of 5.0A directed to the east. The two wires are separated by 8c.m. What is the magnitude of the magnetic field at the point that is 5.0 cm from each of the wires.Homework Equations B= \frac{μI}{2∏R}The Attempt at a Solution I know...
  34. Artlav

    Why light does not travel in wires?

    Asking in most general shape, why do signals from upper Ghz and above don't seem to travel in wires? Radio frequency waves can propagate in wires - you can have a signal like that being induced from the wave interacting with the wire, being generated, measured directly, and so on. But...
  35. U

    Does electron beams act like current carrying wires to themselves?

    I was just wondering, that if we have two electron beams passing by each other, would there be any magnetic interaction between them ? Just like, electrons in current carrying wires. I asked the similar question earlier but with the change that one of them was a current carrying wire, whereas...
  36. Q

    How does voltage in wires affect conduit and nearby materials?

    Two questions here. From real-world problems, I was hoping someone smarter than me could explain the physics behind some issues I was told about. It's been a long time since I looked at an engineering or physics book, so please bear with me. 1) For a 3-phase motor, I was told that someone...
  37. C

    Maximum Height for Hanging Mass on a Stretched Wire

    Hello first post here. These problems aren't for a specific course just working through an old textbook specifically Vibrations and Waves by A.P. French. I hope it's alright that I include two problems in one thread. Homework Statement Q 3-7) A wire of unstretched length L0 is extended by...
  38. S

    Single phase motors with 3 wires into motor HElP

    Hey I was wondering if anyone could help me, I have a single phase motor with a single capacitor,on a woodworking saw, which the switch broke, it was sprung loaded, so I guess a start run switch. It's for a friend and he took the switch off without marking the terminals, I can't find another...
  39. M

    Determining magnitude of net force with three parallel wires

    Homework Statement Three parallel wires carry a current of I 1 = 3 A, I 2 = 2 A, and I 3 = 1 A, respectively. They are arranged as shown. If r = 2m and L=5m,what is the magnitude of the net force on the bottom wire? <------------------------- I1 r -------------------------->I2 2r...
  40. P

    Why are wires made of many thin threads?

    I am guessing that it is easier to produce that way, and gives it more flexibilty. Are these the reasons for wires being mafe of many thin threads, and are there other reasons? Does it allow for better heat dissipation?
  41. S

    Anyone know how to thermally insulated wires from 4.2K temperatures?

    The wires are allowed to reach 4.2K but preferably slowly. They will be run alongside a helium transfer line. Before the helium runs the wires will be at 78K. I thought there would be products for this, but looking around the best I've found is insulation good down to 172 K...
  42. A

    B field intensity of 2 parallel wires

    Homework Statement Two long parallel wires are a center-to-center distance of 4.60 cm apart and carry equal anti-parallel currents of 4.40 A. Find the magnetic field intensity at the point P which is equidistant from the wires. (R = 4.00 cm). Homework Equations magnetic field for a...
  43. N

    Magnetic field of two current-carrying wires crossing over

    Two long current-carrying wires cross at an angle of 21° ("theta" is half of this) as shown in the figure above. The magnitude of the current is the same in each wire, I=400 A. A wood mouse is running along the dashed line midway between the wires towards the point where the wires cross...
  44. J

    Difference between positive and negative flow in wires

    Does anyone know if I run 12 volts dc at 1 amp power for a distance of 250 feet and one wire is 12 gauge used for positive and other negative wire is 20 gauge will the smaller ground wire affect what the positive wire can carry? John
  45. R

    Problem already solved. concept help needed. Four Wires in a square.

    Four Wires form corners of a square. Force exerted by 3 of them on 1. Concept help! Homework Statement side length "a"= 5.5 cm current through wires "I" = 1.6A "L" of lower right wire= 1 cm upper and lower left currents are out of the page upper and lower right currents are into the...
  46. G

    Relativistic explanation for magnetic force between perpendicular wires

    I have read about how magnetism arises from electric interactions and relativity. But in that respect i don't see how perpendicular wires can exert magnetic forces on each other. The movement of the charges is perpendicular so length contraction does not occurr in the direction of the current...
  47. F

    How Does a Changing Current in One Wire Affect the Current in an Adjacent Wire?

    Homework Statement So basically there are two parallel wires the wire on the left has an increasing current going north. What would be the direction of the current in the wire left of it? Homework Equations Right Hand Rules The Attempt at a Solution So I'm really not...
  48. J

    Can one burn aluminium wires using an electric arc?

    Could one burn aluminium wires by striking up an electric arc between them and then feeding them towards each other as they are consumed (like an arc light)? I assume the aluminium oxide would be burnt off as a vapour by the high temperature of the electric arc and thus would not inhibit the...
  49. M

    Parallel wires and forces acting upon them

    Two long, parallel wires are separated by a distance of 1.0 m. The current in each wire is 1.0 A. Which of the following is the magnitude of the force on 1.0 m length of each wire? A. 2π×107 N B. 2×107 N C. 2π×10–7 N D. 2×10–7 N Homework Equations Force on wire= B field density * Length...
  50. T

    Copper rod vs. bundle of wires in a magnetic field

    I was wondering what the difference in current is if there is one when you have a bundle of copper wire passing through alternating magnetic fields verses a solid copper rod of the same diameter. Will the rod have more current because there is more copper? Would it have less because more copper...
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