Wires Definition and 543 Threads

  1. shihab-kol

    I-V graph of two wires and temperature

    Homework Statement Homework Equations ## V=IR## The Attempt at a Solution This is an I-V graph so the slope must represent ##\frac{1}{R} ## Now, $$ R∝Temperature$$ {This is assuming that the wires are of metal} Now , since the graph is of ##\frac{1}{R} ## , the steeper the slope the higher...
  2. J

    Solar panel wires shorted togather

    I have a solar panel rated 20 volts and 6 amps power comes in on 4 12 gauge copper wires 2 for ground and 2 for positive and it is 50 feet long if positive and negative are shorted togather will the wire get warm?
  3. D

    Electrical signals -- How do they actually propagate in real wires?

    I am an electrical engineer, and I know that my question is not directly relevant to the pure Physics but anyway, my question is that how electric signals move inside wires? how to initiate the electrical signals knowing that in order for the electron to move in a circuit, we need a continuous...
  4. I

    Connecting three spheres with wires redistributes charge

    Homework Statement There are three identical conducting spheres, A, B and C. They are initially charged as q_A = 0, q_B = 0, q_C = +Q. Initially, A and B are connected by a wire. Then the spheres are connected (by a wire) as follows: 1) A to C (while A is still connected to B) 2) Connection...
  5. L

    Magnetic Field of a Line between two wires

    Homework Statement Two wires with the same intensity but with opposite directions. The magnetic field of the middle line between the two wires is: a) (X) b) (o) c) Parallel between the two wires d) Null e) Non of the above. Homework Equations N/A The Attempt at a Solution Knowing that they...
  6. C

    How can I connect a speaker to my amp without a physical wires

    I am trying to connect a second pair of speakers to my amp without the use of wires. It is really only one speaker position where running wires is impractical.
  7. L

    Magnetic flux between 2 parallel wires

    Homework Statement Consider two long parallel wires each of radius a with a separation distance d between them. They carry current I in opposite directions. Calculate the magnetic flux through a section of length l, ignoring magnetic field inside the wires. My confusion lies in trying to...
  8. F

    Two parallel wires connected to equal alternating currents

    Homework Statement Two parallel wires connected to equal sinusoidal alternating currents with a phase difference of pi rad. How does the force of attraction vary with time (draw a graph)? Q from here...
  9. Asmaa Mohammad

    When will two current-carrying wires touch each other

    Homework Statement Two wires are free to move, the current in each one is 10 A, the mass of each one is 2.5 g, they are separated by a distance of 20 cm, and the length of each one is 5 cm. Determine (i) where and (ii) when will the two wire touch each other if they were standing parallel to...
  10. joeyc

    Force per unit length acting on four parallel wires

    Homework Statement An arrangement of four wires, in cross section, with θ=30° and u=5cm. Wire 2 and wire 4 carry the same magnitude of current (I2=I4=10mA) directed out of the page. Wire 3 carries current I3=25mA directed into the page. If the resultant force per unit length on wire 1 is zero...
  11. Joshua L

    What are the considerations for analyzing current through thin gold wires?

    Hey all, I've been thinking of a couple scenarios that involve thin wires (ones that have their diameter in the order of 1 mm). Suppose a gold wire with length L and diameter D is suspended straight in room temperature air and connected to some voltage V. Thus, a current will pass through the...
  12. G

    Electrical heating transmission wires

    Hello community. I have a question about electrical heating. I am familiar with the fact that textbooks explain how power losses are reduced by transmitting at high V and low I since P = I^2 X R (equation from Ohm's law and P=I X V) But if you use a different sub for P = I V then you get P =...
  13. F

    Significance of magnetic flux between wires

    Homework Statement Two wires are laid side by side and carry equal currents in opposite directions. Explain why the total magnetic flux density due to the current in the wires is negligible 2. The attempt at a solution I know that having a different direction for the current results in...
  14. B

    What materials do I need to wire a VFD?

    Hi everyone, I am part of a senior design group that is building a dynonameter to test shocks. We are ordering parts tomorrow morning and so I want to make sure that I am not missing anything. I do not have any experience with VFD's or three phase motors but I am doing my best to research and...
  15. M

    Alternating Current, live and neutral wires

    Hi there, I am a teacher and will be teaching the topic of alternating current soon. I have not taught this before and have certainly not studied this in many years so I am trying to get a full understanding and am looking for a bit of clarification. So I know that the current supplied by the...
  16. O

    Voltage drop across connecting wires?

    Homework Statement Suppose you want to run some apparatus that is 95 m from an electric outlet. Each of the wires connecting your apparatus to the 120 V source has a resistance per unit length of 0.0065 Ω/m. If your apparatus draws 2.9 A, what will be the voltage drop across the connecting...
  17. S

    Two Parallel Wires: Magnetic Fields

    Homework Statement Two long parallel wires are a center-to-center distance of 1.10 cm apart and carry equal anti-parallel currents of 9.70 A. Find the magnitude of the magnetic field at the point P which is equidistant from the wires. (R = 10.00 cm). (See Attachment for orientation) I = 9.7 A...
  18. moenste

    Find direction of current in a magnetic field

    Homework Statement The diagram shows a uniform magnetic flux density B in the plane of the paper. Q and R mark the points where two long, straight and parallel wires carry the same current, I, in the same direction and perpendicular to the paper. The line through QR is at right angles to the...
  19. moenste

    Magnetic flux density between two wires

    Homework Statement Two identical wires R and S lie parallel in a horizontal plane, their axes being 0.10 m apart. A current of 10 A flows in R in the opposite direction to a current of 30 A in S. Neglecting the effect of the Earth's magnetic flux density calculate the magnitude and state the...
  20. moenste

    AC through the wires, forces acting in/out of phase currents

    Homework Statement Two parallel wires have currents passed through them which are in the same direction. Draw a diagram showing the directions of the currents and of the forces on the wires. Alternating currents are now passed through the wires. Explain what forces would act if the currents...
  21. moenste

    Point between two wires at which the flux density is zero

    Homework Statement A long wire (X) carrying a current of 30 A is placed parallel to, and 3.0 cm away from, a similar wire (Y) carrying a current of 6.0 A. What is the flux density midway between the wires: (a) when the currents are in the same direction, (b) when they are in opposite...
  22. Deebu R

    Temperature at the junction of 2 wires

    Homework Statement The thermal conductivity of copper is 4 times that of brass.Two rods of copper and brass having same length and cross section are joined end to end. The free end of copper is at 0 degree C and the free end of brass is at 100 degree C. The temperature at the junction is...
  23. MickeyBlue

    Tension in two wires at unknown angles

    Homework Statement An object at rest is suspended from two strings (A and B) as shown in the diagram, with A shorter than B. The object pulls on the point O with a force of 20 N. Each of the strings also exerts a force on the Point O. The angle between the strings at O is 90o. Which of the...
  24. Paul Nicholson

    The easiest way to run wires through a rotating shaft?

    I found this closed thread and I'd like to continue it: https://www.physicsforums.com/threads/design-question-wiring-motors.459672/ I am building a rotating ceiling mount (or rotating a floor plate) and am trying to solve the problem of the continuous rotation servo motor getting in the way of...
  25. V

    Two movable wires in Magnetic Field

    Homework Statement Homework Equations EMF induced in a moving wire =Bvl The Attempt at a Solution When right wire is given a velocity v , an initial emf Bvl is induced in right wire due to which current starts flowing in the loop . Initial current i = Bvl/(2R) The left wire experiences a...
  26. Z

    Find the force between two wires

    Homework Statement Two rectilinear wires with length 100 m have the intensity 2 A. The wires in are perpendicular directions with distance 5 meters from each-other. Find the force they interact. Homework Equations F=(I1*I2*μ0*l)/(2*pi*d) The Attempt at a Solution...
  27. H

    2 microstrip capacitance with dielectric

    Hi guys, I've been trying to figure out how the capacitance of two microstrips, separated a distance d, are influenced by the presence of a dielectric. The dielectric will be a height (h) above the strips and has restricted movement. Using the electric potential I am able to derive a function...
  28. CARNiVORE

    Two Long Straight Wires Carrying Curent

    Homework Statement Homework Equations B = μ0*i/(2PI*r) The Attempt at a Solution First of all, if you're looking at this, that means you intend to help me study for my upcoming physics exam on a Friday night. If you fit into this category of people, then god bless your soul. I should state...
  29. G

    Magnetic Field from two parallel wires

    Homework Statement Each of two long straight parallel wires separated by a distance of 24.0 cm carries a current of 5.00 A in the same direction. What is the magnitude of the resulting magnetic field at a point that is 14.0 cm from each wire? Homework Equations U0I/2pir U0I/4pia(cos(theta)...
  30. D

    Why energy is lost in capacitor if wires have no resistance?

    The question in textbook:- A 4uF capacitor is charged by connecting it to 200V supply.It is then connected to an uncharged 2uF capacitor.How much electrostatic energy of the first capacitor is lost in form of heat and electromagnetic radiation? My question is that why the energy must be lost...
  31. DoobleD

    E field inside wires during transient state

    I've come across an instructive paper which explains qualitatively what happens inside wires of a simple circuit during the transient state, leading to the steady state where there is an uniform E field everywhere inside the wires. Here are two figures from the paper which are pretty much self...
  32. S

    Force between two current carrying wires

    I've learned how to know the direction of force on a current carrying conductor when placed in a magnetic field.( Fleming's left hand rule) Is there a similar rule to calculate the force in this case? Or should the force be 0 since the wires are perpendicular to each other? In general, how to...
  33. 1

    Does current flow in both wires or in one in our homes?

    If we have a source of AC current with two terminals ( A and B ). We connect a device with this source. Now we say that one wire is live and other is neutral. But my question is that, how one wire is neutral. As we say that in AC current the terminals change the polarity. Its mean that some...
  34. S

    Size of current in parallel wires

    Homework Statement Two parallel wires are positioned at l = 2.76 cm apart. Initially a current I1 = 9.57 A flows up the screen through wire 1, and wire 2 has no current in it. A current is then sent through wire 2. The magnetic field between the two wires, is found to be 0T. What is the size...
  35. S

    What is the current flowing through the wires?

    Homework Statement A power plant produces energy at a voltage of V = 15435 V. Before being sent along long distance power lines this electricity is sent through a transformer with 112 turns in the primary coil and 8613 turns in the secondary coil. If the wires have an efficiency of 99.60...
  36. Antonius

    Magnetic Field [Perpendicular wires]

    Homework Statement Homework Equations Biot-Savart Law: ## dB = μIdl/4πr^2 F = ILxB The Attempt at a Solution I have not tried to solve it. BUT, please check my approach. I want to make sure my method is correct and whether there is a flaw or no. I am trying to set up an integral here. I am...
  37. Z

    Wires and resistance heating questions

    Hey everyone, I had a few questions about resistance of wires and heating. I'm a materials engineer looking to replace traditional copper with something more lightweight, however, the alternatives have high resistance. For comparison say copper wire has .01 ohm/ft the other material could be 1...
  38. F

    Mutual force between AC current carrying wires

    Hello Everyone, I have wondered about this for a while but have not found a book or article that deals with this topic. Two wires carrying DC currents directed in the same direction attract each other (repel if the currents go in opposite directions). What happens if the currents in the two...
  39. S

    Overhead power lines wires and strings deviation

    Hello to all of you. I have the following case to solve. I have three overhead power line towers. The first and the third are with tension insulator strings, and the second is with suspension insulator string. During the design process i noticed that the second tower is located incorrectly and...
  40. Fluxxx

    Direction of magnetic field and force in current wires

    I read this example in a book and I'm thinking about what is the "determining factor" of the directions of the magnetic field vector B and the magnetic force vectors F. If we start by looking at wire 1 in picture (a), if we only know the direction of the current (we call this "v"), can we...
  41. T

    Electric Charge Applied on Two Wires of Electroscope?

    Homework Statement A large electroscope is made with "leaves" that are 78-cm-long wires with tiny 24-g spheres at the ends. When charged, nearly all the charge resides on the ends of the spheres. (See diagram attached) If the wires each make a 26° angle with the vertical, what total charge Q...
  42. H

    How to find forces in wires at equilibrium

    I need to find tensions in suspensions wires on the picture: I wrote 4 equilibrium equations for moments in A, B, C, D and equilibrium about y-axis, but i got matrix with rank two. \begin{pmatrix} 3 & 2 & 1 & 0 \\ 0 & 1 & 2 & 3 \\ -1 & 0 & 1 & 2 \\ -2 & -1 & 0 & 1 \\ 1 & 1 &...
  43. G

    Electric field at point between two finite charged wires

    Homework Statement Two parallel charged wires are in vacuum. Width of wires is equal to the distance between them. Calculate electric field in the middle (point A). Homework Equations Superposition The Attempt at a Solution Using superposition, y components on vector E are cancelled. I get...
  44. A

    Solving Tension in Wires for Fixed Plate

    Homework Statement A plate is fixed to the ceiling by two wires and to the wall by a single wire. The wall wire is cut. Calculate the tension in the two remaining wires. mass = 800 kg g = 10m/s² Dimensions in sketch Homework EquationsThe Attempt at a Solution Equations: Ra*cos30 + Rb*cos30 =...
  45. toforfiltum

    Particle flow in wires of same current but diff diameter?

    Homework Statement Homework Equations I=Q/t The Attempt at a Solution I chose B because since current is equal in both wires, I thought that the rate of charge flow is equal. Isn't that the definition of current?? Apparently I'm wrong since the answer is D. How can this be?
  46. R

    Circuit Questions -- Electrons flowing in wires and a resistor

    Homework Statement Homework EquationsThe Attempt at a Solution I have selected what I thought were the right choices in the original question. Resistors reduce current so electron flow should have been greater on the right. Also, the electrons flow opposite to current so potential is higher...
  47. J-dizzal

    Log hanging from 2 steel wires. stress/strain youngs modulus

    Homework Statement In the figure, a 128 kg uniform log hangs by two steel wires, A and B, both of radius 1.15 mm. Initially, wire A was 2.80 m long and 2.00 mm shorter than wire B. The log is now horizontal. Young's modulus for steel is 2.00 × 1011 N/m2. What are the magnitudes of the forces...
  48. lonely_nucleus

    Do capacitors block unwanted ac frequencies in the wires?

    I have been studying capacitors and inductors recently and I have seen this video. I have a few questions about capacitors and inductors. Capacitors: 1.how do capacitors discharge? 2. What happens when you apply direct current through a capacitor? 3.Do capacitors only allow certain...
  49. D

    Force between two superconducting wires

    Consider two parallel superconducting wires. Both the wires carry the same current and the current is going in the same direction. do they experience a magnetic force attracting them together? Or do their magnetic fields behave differently?
  50. D

    Magnetic force between two wires

    I'm wanting to know the force between two wires carrying current but I think I did something wrong when I calculated it. Here is my working. I got a value of 0.0021365 ohms for both wires from http://chemandy.com/calculators/round-wire-resistance-calculator.htm 1000 volts pass through the...
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