Wire Definition and 1000 Threads

Divide volts by current to get resistance which is 8. Multiply both sides by 8 and sigma to get: $$\frac{1m}{8\Omega\times10^{-4}m^2} = 1250$$ But this answer seems to be way off. How did I go wrong? Thanks

We need to find each variable. ##I## is already given to us as 8 amps. The charge of an electron is 1.6 x 10^-19 coulombs. The cross sectional area will just be ##\pi(1.2∗10^−3)^2## m^2. Now we need to find the free electron density. We are given the density of of copper and can use dimensional...

On the Internet, I have read that the energy doesn't flow in the wire, for example in a very simple electric circuit made of a battery and a closed loop. When one computes the Poynting vector ##\vec S \propto \vec E \times \vec B##, one gets that its direction is towards the center of the wire...

Hi, I need to calculate the temperature of a wire, due electric current passing through, and I have no idea how to do that. I need it for a device that I want assemble. I'm using one single thread (strand) of speaker cable, like you can see in this picture: Again, Just a single thread that...

Considering a reference frame with ##x=0## at the leftmost point I have for the leftmost piece of wire: ##\int_{x=0}^{x=2R}\frac{\lambda dx}{4\pi\varepsilon_0 (3R-x)}=\frac{\lambda ln(3)}{4\pi\varepsilon_0}##. The potential at O due to the semicircular piece of wire at the center is...

why would the current flow through a person when it is already flowing through a copper conductor that is connecting the terminals.

Paper has a grain direction – the direction of the long fibres. For several reasons, publishers always print hardcover books with the grain of the paper in the same direction as the fold. I'm working on a book that will be 2:1 wire bound (two holes to the inch). I was wondering what the grain...

We are getting 3 phase power delivered to our property via our own dedicated transformer. We want to rewire the house and other buildings so that we can use different appliances on different phases. We have 4 air conditioners, 3 hot water units and the usual assortment of things you would find...

When wiring a 240 volt AC circuit, I've always assumed that it's important for L1 and L2 wires to be the exact same length, in order to avoid introducing a phase shift that would reduce peak voltage. Length differences can accumulate when the wires enter a panel and need to go slightly...

B equals 50*10^-7 T (at first instance) Fm equals 8*10^-20 N (at first instance) I know Fm is perpendicular to the velocity, and I know the estimation of the trajectory (somewhat similar to the curve y=lnx). Since I think vertical velocity will be constant, only changing the x component, I...

Hey! I had a question about this problem. I did (1) Using $$R_{0}=\rho\frac{l}{A}$$ For (2) I assume the question means that the radius increases by a meter. So I used $$\bigtriangleup L = 2\pi (r_{E}+1) - l$$ and then I used that L to find the new R. Then I said $$\bigtriangleup R = R-R_{0}$$...

I know that the whole topic of inductance in a straight wire is complicated (and has led to some heated discussions in this forum :smile:). I followed Rosa's derivation and can see that it leads to an inverse relation of the inductance to the wire radius, and from what could understand, the...

I don't really have any equations or idea how to solve this. I searched for relevant equations and only R=Rref(1+α(T-Tref)) pops up. I wasn't given any temperatures so I guess there must be some other way to solve this. Maybe anyone has idea how to approach this?

Somehow this answer is incorrect , but i realize that even numbers are hipothetical , 45 coulumbs is too much charge , what is wrong in my calculations?

Good day. We know how simple objects, such as 1D wires behave when a simple harmonic wave travels along a wire, or two wires knotted togethe.We also know what happens if you excite a circular thin disc with a single frequency. Are there some material I can read on, that considers the effect...

Preface: I am new to physics and am trying to learn on my own, though I hope to take a class soon. I looked for a forum for beginners but didn't see one, but this seemed to be the closest forum. So I hope I can get some help with my question here. If it is the wrong forum, feel free to...

If the wire is bent by three pivots, I want to find an expression that represents its shape. There will be tension of wire and other physical factors. How can it be expressed?

i really have tried all the formulas out there and can't seem to get a solid answer

I am stumped and would like a hint. Answer choices:

$\tiny{2.5.1}$ Electrical Resistance of a Wire 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 432 feet long and 4 mm in diameter has a resistance of 1.24 $\Omega$ find the length of a wire of...

First I wrote in ##S'##, by using Gauss theorem $$ \int_{\Sigma} \underline E' \cdot \hat n d\Sigma = \frac Q {\varepsilon_0} \rightarrow E'(r)2\pi rH=\frac{\lambda'H}{\varepsilon_0} $$ $$ \underline E'(\underline r)=\frac{\lambda'}{2\pi\varepsilon_0r}\hat r $$ Its components are...

I can calculate the fields generated by the cylinder and the wire but I don't know how to calculate their vector sum to evaluate it at point A. Cylinder field inside: ρR^2/2rε Cylinder field outside: ρr/2ε Field generated by the wire: λ/2πr I should break the fields into components but I don't...

i don't understand the answer: Nichrome has a higher resistance than copper wire. There is a greater potential difference across the nichrome than the copper wire. From ,the resistance of nichrome is low enough such that there is significant power output. ^ i feel like the bold parts contradict...

Hello, I am wondering why a wire that was connected from a MAIN BUS BAR to the top side of a switch and when turned ON burnt immediately and the wire connected from the bottom side of the switch to the BUS BAR needing power slowly burnt. I'm thinking the wiring was reversed- Correct me...

Homework Statement:: Not a specific question, more just a conceptual clarification for a project. But generally: What is an equation for the effective skin depth of a multilayered (in this case only 2 layers) wire, as a function of the resistivities and relative permeabilities of both of the...

Hi I am working through some notes and came across this example. The wire rotates at angular frequency ω so the polar angle is given by θ = ωt. The generalised coordinate is r. Using the Euler-Lagrange equation leads to d2r/dt2 = rω2 The notes then state that this leads to the solution r = Aeωt...

I used the voltage of the power supply and resistance to solve for the current in the larger circuit (20V/5ohms=4 amps). I am not sure if the equation listed above is the correct one I should be using, but I tried it using the following numbers. For omega, I used 2*pi*frequency. N should...

A transformer supplies 240VAC to a 20A circuit breaker as shown in the attached image. I believe I can use 12AWG wire for wires X1, X4, 2 & 3. However, I'm not sure what gauge wire the neutral should be. Maybe 12AWG or something larger?

W=Q*V 2*10^20 Q * 3,7 V= 7,4*10^20 ??

A copper wire contains 3.0 *10 ^ 22 number of charges on 1 meter wire. What speed do the electrons move when there is 2 A current in the wire. t=q/t=3,20*10^3 C/ 2.0 A = 1,5*10^22 s v= 1m/1,5*10^3s= 6,6*10^-4 m/s

I do not understand how this type of exercise is solved because I have not had a solution to such an example. I would ask you to show me the solution of this exercise step by step, so that I understand how to solve it. I appreciate your help. Thank you.

So force on a current carrying wire = ILxB. If I have a bunch of bar magnets making a uniform magnetic field of strength B, then a 1 meter long wire of 0 ohms carrying 1 Amp, the force on that wire is (1)(1)xB = 1B. If I let that force move the wire for a time T, let's assume the wire moved a...

An AWG 4 wire has rating of 85A for 75C temp. If there was only 1 foot of AWG 4 connecting the bus bar and the electric meter. How much current can the 1 foot take? How is the 85A for 75C temp measured or computed?

2 separate big conductors initially charged Q1 and Q2. Then connect them with an ideal wire (no resistence). The charges Q1 and Q2 will go to the 4 surfaces (marked red). All the 4 surfaces have an area A. Suppose the 2 conductors form an ideal parallel plate capacitor. How to determine the...

I'll try to explain to you my thinking behind this problem... tell me if it's correct or not. In short, I have assumed the area enclosed between the wire and the left side of the coil to be ##A## in which is present a ##-\hat{z}## field, and noticed that the flux it generates must be canceled by...

Hi, I started with calculating the moment of inetria of the rod: I = ⅓ML^2 + M(3/2 * L)^2 = 31/12 ML^2 and I thought that the reaction force in the first case will be equal to centrifugal force: F1 = Mω^2*(3/2)L Angular velocity is calculated from the conservation of energy: Mg3/2*L=1/2 * Iω^2...

hi guys i was trying to solve this non linear ode using the shooting algorithm in Matlab : i am not sure how to solve it using the normal shooting algorithm i have , since no other boundary at x = L/2 was given to check the shooting ?! function dTdx = bar_temp(x,y) k = 72; h = 2000; epsilon =...

I have attached the homework with some of the solution. I have ciuple of questions about it. For part b, what else I can say? I think the copper wite is ductile . Elastic and plastic behaviour have already been mentioned. I need to add another word to describe it. Can say it's hard ? Or...

A quick description. A single straight wire and a second straight wire, both wires are electrically as well as physically separated, the physical separation distance assume is very small in order for the B field experienced by the second wire to be sufficiently strong. In all cases one of the...

∫ H.dl = ∫ j_f .dS = I_f ∇ x H = j_f I'm not sure how to actually solve this?

I'm in an intro E&M class, and I'm trying to distinguish between Motional EMF for loops of wire and conducting plates. This question might be kind of silly, but are Eddy currents pretty much the same thing as induced currents in a loop of wire? More specifically, what I am trying to ask is if...

I've written a calculator that computes the number of conduction electrons in a segment of wire with a specific gauge. For a 1 ft segment of 24awg copper wire, this is what it prints out. AWG [0 - 36]? 24 Wire length (mm) (0 - inf)? 304.8 AWG 24 radius: 0.255 mm dia: 0.511 mm area...

So I know current is just coulombs/second. Electrons are also in the unit of coulombs, so I can get coulombs to cancel. 7.9C/s/1.602E-29C = 4.93133E29 1/s Now I just need to get mol on top. There are 6.022E23 electron in a mol so 4.93133E29 1/s / 6.022E23 atoms/mol = 8.1889E5 mol/s. Now my...

$$B = \frac {\mu_0 I}{2 \pi r} $$ By Right-hand Grip Rule, the direction of the magnetic field by wire in y-axis is into the paper (z) while the direction of the magnetic field by wire in X-axis is upwards (+i) The answer state the Magnetic field is in the (i - y) direction though. Next...

If ##\tau= 0.0727, N=60, i=1.3, B=1.0,## and ##\theta=15##, I tried the following calculation: ##\tau=NIABsin\theta## ##\tau=NIs^2Bsin\theta## ##s^2=\frac {\tau} {NIBsin\theta}=\frac {.0727} {60*1.3*1*sin(15)}=0.0632 m=6.32 cm## The answer is probably right in front of me, but I don't know what...

In the picture below, the direction of the magnetic field lines can be determined by using the right-hand rule with the thumb pointing in the direction of the current. If we use the right hand rule in the picture below, thinking of the yellow arrow as the current, we would not get the correct...

Assuming the electrons are non interacting and spin degenerate, the conductance of a quasi one dimensional quantum wire is quantised in units of 2e^2/h. For small voltages, we simply count how many bands have their bottoms below the chemical potential and multiply this by 2e^2/h. This is due to...

I understand how the weaker and stronger field occurs but I don't understand why the force on the wire is directed from stronger to weaker field. I mean why not from weaker to stronger? I also want to ask about Newton's 3rd law in this case. Newton's 3rd law states that for every action there...

Could someone please help. i need to connect a 12vdc motor which can draw 16 amps to a switch that has an led on it. the led is rated at 3v 20mA. The power supply i am using is rated to put out 12vdc at 30A I thought of the possibility of adding a resistor to the positive pole of the led. In...