# What is Wires: Definition and 543 Discussions

Wiley Interdisciplinary Reviews (abbreviated WIREs) is a set of peer-reviewed scientific journals that each publish interdisciplinary review articles on high-profile topics. The series was established in 2009 and is published by Wiley-Blackwell. Each journal publishes new review articles every month.
The journal series won the 2009 R.R. Hawkins Award from the Association of American Publishers.

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1. ### I Where is the lost energy in this example?

We connect the charged capacitor to the no-charged capacitor (consider the wires to be ideal R=0), the final energy is less than the initial energy of the system. Where is the lost energy? (see example blew)
2. ### B Stationary charge next to a current-carrying wire

(1) https://www.youtube.com/results?search_query=relativity+and+electromagnetism (2) If I understand this correctly, then, well, shouldn't all current-carrying wires exhibit a small amount of positive charge?
3. ### Calculate Max Resistance for 2 Parallel Wires

Hi, I am not sure if I have calculated the task here correctly: Based on the drawing, I now assumed that the two resistors are connected in parallel. The total resistance can then be calculated as follows ##\frac{1}{R_T}=\frac{1}{R_1}+\frac{1}{R_2}##. Since the two wires are made of the same...
4. ### Magnetic field force between two perpendicular wires

There are a couple of problems with the same setup. On plugging in the values and solving for the integral, I am not getting the expected values of the force. Is there something wrong in the solution attached?
5. ### B What wires should I use for my wire chamber?

I want to make my own multi-wire chamber for school, and I wonder what kind of effect different wires will have on the efficiency. After reading many papers containing research for wire chambers, I saw that all of them did tests with wires made of gold plated tungsten wires with a diameter of...
6. ### Reactive metal wires in a fuel oxidizer mixture

Suppose there's some slow burning pyrotechnic mixture like KNO##_3## with powdered charcoal, and several really thin threads/wires of magnesium metal (or zirconium or magnesium/aluminum alloy) are made go through a pile of that mixture. Now I would guess that because a mixture of finely powdered...
7. ### I Exploring Magnetic Force: Magnet vs. Wires

I understand the iron fillings become little magnets all pointing in the same north south direction similar to the spin aligned electrons in the permanent magnet. Similarly, a compass near a wire traces out the magnetic field lines ie North/South. My question is how do I reconcile the fact that...
8. ### I Faraday induction in constant B field, with non-conduction wires

A standard textbook problem features a constant B field and a conducting loop that increases in area at constant rate. It is easy to work out the induced EMF and the associated electric field magnitude and direction (CW or CCW). The magnitude of the E field is E = B v where v is a velocity...
9. ### I Preventing parasitics for wires?

This is related to a question that I asked here: https://physics.stackexchange.com/questions/650709/one-way-magnetic-shielding. Please take a look at the check-marked answer. There is a material that can act as a one-way magnetic/electric shield. My question is if this material were to be used...

11. ### Stewart-Tolman Effect (Current caused by Acceleration of wires)

Consider the inertial reference frame in which the positive ions forming the crystal lattice of some portion of a metallic ring are at rest. In this frame, an inertial force of mra exists. Consider the electrons in this portion of the metallic ring. The inertial force of mra is exerted on the...
12. ### 4 (insulated) wires from electric pole for underground 3-phase service

Hi all. This is probably a simple question, but I am hoping for some guidance on why a service would be delivered with 4 wires as seen in the image. It appears fairly common around here (northeast U.S.), if not standard, for one of the phase-conductors to be 'double-tapped' and go underground...
13. ### Inserting pulling metal wires in existing empty conduit

Inserting wires in existing empty conduit There is an empty PVC conduit size 1.5748" (40mm) in the main entrance panel. It was built around 8 years ago. There is metal wire (see picture above) inside the conduit to pull the main electrical wires from the inside or outside. Is there any...
14. ### Solenoid wrapped with 2 wires?

I have a bit of a mystery with a circa 1905 solenoid and not sure where to turn, hoping someone here might have some insight. The particulars Circa 1905 solenoid (application is an electromagnet in a self-winding clock) 8 layers of windings of 2 different cotton sheathed copper wires paper in...
15. ### Whether charges can stay inside wires or on the surface of a conductor

There's an isolated capacitor initially carrying nonzero net charge. Then place the capacitor in a circuit connected with ideal wires (no resistance). Where will the excess charge go? Can they stay in wires or on any surfaces of conductors in the circuit? Electric field needs to be 0 everywhere...
16. ### Are real nano wires like the ones in Larry Niven?

Hi, this is my VERY FIRST post so if I've made a bundle of noob mistakes accept my pre-emptive mea culpa. I did read and like the rules. I have seen some stories in Phys.org about nano wires and I immediately thought of the nano wires in Larry Niven Known Space milieu which can cut right through...
17. ### Identical Wires with different voltage--does electron behavior differ?

Homework Statement:: I am studying on my own, so I don't have a specific homework statement, but want to make sure I am thinking about things correctly. What I am wondering is if you have equivalent wires, let's say both are made of copper, and one wire has three times the voltage of the...
18. ### Position for maximum electric field between two wires

For the first part, since $$E(r) \propto \frac{1}{r} \hat{r}$$ by the principle of superposition the maximal electric field should be halfway in between the two wires. Then I'm not sure how to go about the second part of the question. I understand that the total potential due to the two wires...
19. ### Magnetic field Cancellation in AC wires (How?)

Why do the magnetic fields in-between the wires does not seem to cancel? Even those outside each wire? (the fields do are not in opposite direction). Yet most of the people I have talked to until now says that such magnetic fields do cancel? I am confused...
20. ### Tension forces of two wires in comparison to the gravitational force

The correct answer is the second one. I honestly have no idea why this is so. I understand that the right rope has less tension that the left one since it's at a shallower angle from real world experience, but I don't really know why this is so, let alone how the forces compare to gravitational...
21. ### Could Monomolecular Blades Realistically Cut Through Tank Armor?

A common thrope in SF (Endymion, Battle Angel Alita, even Three Body problem mentioned it), something that is so sharp that it can easily cut through tank armor. Could it possibly work in reality without some sort of stabile superheavy element?
22. ### Magnetic forces on current-carrying wires

please correct me if I'm wrong. is it for the question b, F/l= 0.50 right? does that mean the resultant magnetic force at X is determine by the force at Y and Z? do I need to consider the direction to solve the equation? first step to know the direction of each conductors I use the right hand...
23. ### Force between two perpendicular wires

μThe magnetic field is supposed to be B=μ0i/(2πr). I think that the force would be aimed upwards. Now I tried to divide the wire BC to infinite smaller wires where B is roughly constant in each one of them. What I get is: However this is not correct when I plug the relevant numbers in it...
24. ### Calculate the extension of a spring between current-carrying wires

From what I understand, the force between two current-carrying wires can be calculated as: $$\dfrac {F}{L}=\dfrac {\mu _{0}I_{1}I_{2}}{2\pi R}$$ Doesn't this mean: $$\dfrac {F}{L}=\dfrac {\mu _{0}I_{1}I_{2}}{2\pi 1^{2}}=\dfrac {1}{2}kx^{2}$$ ? \dfrac {\left( 4\pi \times 10^{-7}\right)...
25. ### Magnetic Forces & Moving Wires: The Right Hand Rule

OK so a wire with a current creates a b field in accordance with the right hand rule. Now moving charge will feel a force (if its moving in the correct direction) while stationary charges will not feel a magnetic force. What I am curious about is if we move the wire itself, will a stationary...
26. ### The distance where the magnetic field of two wires is zero

Homework Statement: The distance between two parallel long wires, carrying currents equal to i and 3i respectively, is d as shown in the picture. What is the distance from the wire carrying the current i at which the magnetic field is zero Homework Equations: guess biot-savarat Being two...
27. ### Getting less total B-field from two infinitely long parallel wires

I got 4.7*sin(377t) micro-Tesla for each wire, but where are they getting the total B-field equaling 0.78 micro-Tesla? Is it some hidden trigonometry?
28. ### What is this paste on the wires?

This is a servo, there is some sort of a hard white paste keep the 3 wires from moving around and accidentally touching each other. It appears to melt with heat. Does anyone know what it is? My guess is putty. Thanks in advance
29. ### Force on a metal bar across two wires in a magnetic field

I need help with the problem above
30. ### Magnetic Fields from Current Carrying Wires

I've had a lot of problems that involve a segment of current carrying wire, for example when you have a square loop of wire. I have a formula for "long" wires that is B = μ0 * I/(2 * π * d). Can I use this for shorter wire segments, and if not, what formula can I use?
31. ### I Do two perpendicular wires exert a force on each other?

I have a question for my E&M assignment (I'm not putting it in the homework thread since I just need more of a concept check) that involves a straight wire with current through it. If you have a wire with a current through it, and you have a rectangular wire also with current, to the right of...
32. ### I ask for your help understanding the limits of my wires

Hi! I have wires that have printed 600V 16 AWG on it. I found this table: http://www.basicsofelectricalengineering.com/2017/07/basics-of-wire-gauge-and-awg-system.html . As I understood then long wires can be used to transmit 3.7 amps and short ones 22 amps? Also does it depend on voltages...
33. ### Ratio of the length of resistive wires in a square

Homework Statement In a given square ABCD each side is of 1 m and resistance of wire is 1 ohm/m. A resistance of 1 m is connected from A to E (which lies on side CD). A constant potential difference is applied across A and C, if potentials of B and E are same then find CE/ED. Homework...
34. ### I Electric & Magnetic Fields Inside Conducting Wires

Suppose a straight current carrying wire is immersed in a uniform electric field along its axis. For this problem, please don't worry about complete loops or return paths, just consider a segment of straight wire carrying a current. Since external electric fields don't get inside conductors due...
35. ### Magnetic Forces on infinite current-carrying wires

Homework Statement A) Three infinite, current-carrying wires are arranged as shown below. In terms of the given quantities, determine the magnitude and direction of the magnetic force per length acting upon wire 2. (Part A.jpg attached) B) Three infinite, current-carrying wires are arranged as...
36. ### Why are there three wires in secondary coil of transformer?

This is a 12-0-12 transformer that I intend to use in my circuit: Why are there three wires in the secondary? One is of course the neutral (in black). Why are there two live wires? As an additional question, can I use four 1N5408 rectifier diodes to convert the output of this transformer to...
37. ### Best way to connect 8 wires together?

Okay this may seem like a basic question. I was wondering what would be the best way to connect 8 wires to a single wire. Here's a simple diagram that shows what I'm trying to do: I've been looking around and I've found things like this: Although it seems that there is no larger one that can...
38. ### EMF Oppsition in Adjacent Wires +/- Swing

Can someone please help with this thought experiment? I have sought advice elsewhere but it remains unclear to me. I have a straight piece of two conductor "figure eight" wire (like speaker wire or US power cord) laid out left to right. I connect the output from a push-pull type audio...
39. ### Ampere definition and infinite wires separated by 1 meter

Homework Statement 3 - 2 , 1 km wires ( so acting like infinite wires ) , both have same current , no direction specified , , separated by 1 meter distance and having between them a magnetic force of module 0.02 N . find the current i= Homework Equationsthe definition of 1 ampere has same...
40. ### Flux between two current-carrying wires

Homework Statement Two long, parallel copper wires of diameter 2.5 mm carry currents of 10 A in opposite directions. Assuming that their central axes are 20 mm apart, calculate the magnetic flux per meter of wire that exists between those axes. What fraction of this flux lies inside the...
41. ### Magnetic field at the center of 3 wires carrying current?

Homework Statement each wire carrying 10 Amps a = 0.3 meter point o located in the center Homework Equations B = permeability constant * I / ( 2 ##\pi## r) r = distance between O and the wire r perpendicular to B and I A = carrying current into the page B and C = out of the pages The...
42. ### Unsure of how to approach this type of problem—Current densities in wires

Homework Statement Homework Equations J = nqvd J = I/A Q = It The Attempt at a Solution Basically we check whether the variable that we are looking at is proportional or inversely proportional. However, at what part do we stop? Where is it okay to substitute say Q = It and where is it not...
43. ### Force between Parallel Current Carrying Wires

Homework Statement Two parallel wires have currents that have the same direction, but differing magnitude. The current in wire A is I, and the current in wire B is 2I. Which one of the following statements concerning the situation is true? A) Both wires attract each other with the same force...
44. ### How to determine the wire gauge of thermocouple wires?

Homework Statement A resistance thermometer bridge circuit shown below has a designed maximum temperature of 150°C, ignoring the effects of connecting wire resistance. If the connecting loop is 200 m determine the smallest gauge (swg) of copper wire which must be used if the indicated maximum...
45. ### The magnetic flux density at point P between parallel wires

Homework Statement In the picture at points A and B are two thin parallel wires, where traveling currents are 15 A and 32 A to opposite directions. The distance between wires is 5.3 cm. Point's P distances from A and B are the same. Calculate the magnetic flux density at point P. Homework...
46. ### Magnetic field put off by high current (causing cross-talk between wires)

Ok so I haven't been on here for a while but I can't seem to find an answer to my question anywhere and really need some help! So I not only am an electronics hobbies but I have fun installing car audio systems as well. The problem I am running into is that I would like to run an alt wire...
47. R

### Wires in an circuit, different materials, heat

Homework Statement In an electric circuit, consisting of copper wires with cross section area of Sc=5mm2 and a temperature of t=25C, a lead fuse is added melting when the copper wire temperature increases by Δt=25C. Find the cross section area of the lead fuse wire Sl=x. specific heat...
48. ### How charges can flow in circuit wires at the same potential

I have this simple circuit I know that if a consider the wire from the + of the battery until the + extreme of the resistor, in this portion the wire has the same potential. The same thing regarding the portion of the wire beetween the - of the battery until the - of the resistor. If this...
49. ### B on center of 2 infinite wires with semi - circular end

Homework Statement Homework EquationsThe Attempt at a SolutionMagnetic field due to both semi - infinite straight wires on P = Magnetic field due to infinite straight wire on P = ## \frac { \mu_0 I } { 2 \pi a } = 2 * 10 ^{-5} ~wb/m^2 ## Magnetic field due to semi – circular wire on...
50. ### Electrical current question -- electrons moving through wires....

I have a silly question. In a simple electrical circuit, we know that the two ends of the wire are connected to different potentials of a battery through the load. Potential difference causes the current flow. But how the wire comes to know that the other end of it, is connected to different...