Wire Definition and 1000 Threads

Homework Statement A bar magnet, with pole strength 0.1 Wb and magnetic length (i.e. distance between the poles) of 5 cm, is placed so that one pole is 2 cm and the other 6 cm from a long, straight wire carrying a current of 6 Amps. The magnet lies in a plane perpendicular to the wire. Find...

Homework Statement How large is the force that tightens the wire A (see picture), when the weight's mass is 670 kg? Guidance: Assume that the wires between the wheels are horizontal. Homework Equations G=mg?The Attempt at a Solution What seems weird to me is that none of the wheels look...

Homework Statement see attachment 2 Homework Equations a. The Attempt at a Solution see atachment 1 i am stuck at problem a. the question is to write down the boundary conditions for that the E field has to satisfy infinetly far away from the wire and at the boundary of...

Hello, I am interested in knowing what happens ta wire trough which current is flowing, when an external magnetic, electrical or both , field is applied? Does the voltage or current change, can it be changed this way? Can you also provide some equations of this phenomenon, and also...

Homework Statement http://web.mit.edu/viz/EM/visualizations/coursenotes/modules/guide10.pdf pg: 10-17 Homework Equations The Attempt at a Solution I do not understand conceptually, why we chose the rectangular surface to take the flux over. Can anyone explain this...

I'm looking for heating wire (to ~200-300 degrees Celsius) that won't disturb a ~weakish applied magnetic field significantly - I would be wrapped it helically around a glass cell which is placed inside magnetic field coils. So if I had two parallel sets of non-magnetic wire attached and coiled...

Homework Statement -I've attached a picture of the problem- An infinitely long straight wire of steady current I1 is placed to the left of a circular wire of current I2 and radius a as shown. The center of the circular wire is distance d(≥ a) away from the straight wire. Let’s find the net...

I don't really understand boundary conditions and I've been trying to research it for ages now but to no real avail. I understand what boundary conditions are, I think. You need them along with the initial conditions of a wire/string in order to describe the shape of motion of the string. I...

I have a question about an object heating up when electricity is applied. When putting electricity (say 10 to 15 A) trough a wire the wire will heat up because of it's resistance for electricity, right? But does anyone know how to do calculations on this? Like how to calculate how warm the...

Hello! Just came across this video, . Does anybody know how to explain this?? Best Regards Kontilera

The title is enough

Homework Statement This is actually a sound wave problem, but I think I'll be fine when I actually get to that part; my issue is that it is a cumulative problem that involves torque, which I haven't had practice with since the fall. It's embarrassing how little I remember how to do from just a...

Is there a formula for finding the temperature of a wire? If I know how many volts I put on a wire, the resistance of the wire per foot, the length of the wire, and the ambient air temperature. Is that enough information to determine what the wire's temperature will be? Do I need more...

Homework Statement There are two alike initially uncharged spheres of radius r at a distance of d>>r, as shown in the figure. a) Switch ##K_2## is closed. What is the force exerted between the two spheres? b) What would be the force between the two spheres, if in the previous experiment...

Homework Statement Find the magnetic field due to a curved wire segment. Homework Equations Biot-Savart Law (differential form) dB=\frac{\mu_{o}i}{4\pi} \frac{d\vec{S}\times \hat{r}}{r^{2}} The Attempt at a Solution In class we found the magnetic field at a point in space (point P) caused by...

This relates to the extension of a uniform cross-section, homogenous, ideal wire which extends within the proportional limit (Hooke's law). From my understanding, only half of the gravitational potential energy lost when the mass is lowered on the initially un-extended wire, is stored in the...

According to Faraday's Law a changing magnetic field induces an electric field, an example of this is if you have a wire close enough to another wire with current flowing through it the first wire will also have current run through it because of the induced electric field by the second wire...

Homework Statement A steel cable is vibrating in its third harmonic. The Frequency is 150Hz 1. What is the length of the cable? 2. What is the wavelength?Homework Equations The Attempt at a Solution I am really stuck

Magnetic field inside infinitely conductive hollow tube Homework Statement There exists a thin-walled hollow aluminum tube (assume σ=∞) of radius 10 cm centered around the z-axis. A long wire with 5 mm radius has a total current 2 mA in the z-direction and is centered initially at x=-5cm as...

Now w/ Attachment: Telephone Wire w/ Load and Characteristic Impedance Homework Statement Please see attachment. Homework Equations I(z)=I+(exp(-γz)) + I-(exp(γz)) V(z)=V+(exp(-γz)) + V-(exp(γz)) The Attempt at a Solution I solved easily for the characteristic impedance and gamma...

Homework Statement Determine the emf induced in the square loop in the figure if the loop stays at rest and the current in the straight wire is given by I(t)=(15.0A)sin(2500t) where t is in seconds. The distance a is 12.0 cm, and b is 15.0 cm. Homework Equations emf = Δmagneticflux/Δt...

Homework Statement We have a charged straight wire with radius ra = 0.2 cm and with charge ta = 3nanoC/m. Around the wire there are two hollow concentric cylinders, so that the wire is in their axis. Let the charge on the first cylinder be of radius rb = 3cm and its charge tb = -1.5nC/m and on...

Homework Statement You have a 1.0 m long copper wire. You want to make an N turn current loop that generates a 1.0 mT magnetic field at the centre when the current is 1.0 A. You must use the entire wire. What will be the diameter of your coil (in centimetres)? Homework Equations...

Homework Statement An infinite straight wire carries a current I that varies with time as shown above. It increases from 0 at t = 0 to a maximum value I1 = 5.2 A at t = t1 = 15 s, remains constant at this value until t = t2 when it decreases linearly to a value I4 = -5.2 A at t = t4 = 26 s...

Homework Statement Problem is attached Homework Equations A formula sheet is also attached The Attempt at a Solution flux=\intB dA from .31m to .82 B=u I(enclosed)/2(pi)(d) d=x dA=dx L so ∫ (u)(I)(L)dx / 2(pi)(x) from .31m to .82m remember x=d in the pic. My answer is 3.9687e-7 and its...

Homework Statement The wires below are infinitely long and some of them are with loops and semi loops. The current I is constant. What is the magnetic field in point O, when R is the distance from it? Questions: In F, E and H, the magnetic field exerted by the terminal infinitely long...

Homework Statement A metal rectangle is close to a long straight current carrying wire, with 2 sides parallel to the wire. If the current in the wire is decreasing, the rectangle is Homework Equations Lenz's Law: the direction of any magnetic induction effect is such to oppose the cause...

Homework Statement I really need help with part c of the question... Consider a long straight wire and a rectangle of wire as shown (see figure). Here the rectangle is a distance d = 4.9 cm from the straight wire at its nearest approach, with length L = 19.0 cm and width r = 7.0 cm (so...

What is the formula to evaluate Lorentz force on a curved current carrying wire in a non-constant magnetic field (given by some known vector field). The standard form of Lorentz force (Fb=BxlI) when B and the wire's length 'l' are constants does not account for this case, nor does the...

Homework Statement Hi everyone, the problem I'm stuck on reads: " Imagine a solenoid 3m in diameter, 5m long having 1164 turns of super conducting cable. What length of super conducting cable is used to wind this solenoid?"Homework Equations Circumference = 2pi*radiusThe Attempt at a Solution...

Homework Statement Two conducting spheres of radii rA and rB are connected by a very long conductive wire. The charge on sphere A is Qa and rA < rB. What is the charge on sphere B? Which sphere has the greater electric field strength immediately above its surface. Homework Equations...

How do you place/define north and south in the magnetic field around a wire with a current running through it?

Homework Statement A thin wire carries current along an arbitrary path, but when it passes through the origin, it is in the +y direction. Denote the magnitude of the current is 9.10A and we consider a point in space whose location is r = (-0.730m)*i + (0.390)*k. Find the contribution to...

Hello all, i would like to ask which is the magnetic moment of a steel and a iron wire with a length of 10,20 or 30cm! Is there any equation from which the magnetic moment can be derived? Thanks in advance :)!

Homework Statement Basically I have the following problem. Given the equation of state \sigma = \frac{b}{T}\frac{L - L_0}{L_0} where b and L_0 are positive constants, calculate the work done over a Carnot cycle by a wire with this equation of state.Homework EquationsI already have the work...

Homework Statement A square loop of wire with a small resistance is moved with constant speed from a field free region into a region of uniform B field (B is constant in time) and then back into a field free region to the left. The self inductance of the loop is negligible In case my image...

1. Given info ( with attached photo) The guy wire supporting a 100ft tower has a tension of 550lbs. Use the distance shown in the figure write the component form of the vector F representing the tension of the wire. 2. My attempt at the solution My first assumption was to make a vector using...

Homework Statement Homework Equations All included above The Attempt at a Solution Well, my solution is there in the box at the bottom. I solved for each of the wire sections individually, two half-infinite straight wires and one quarter-wire. My answer at the bottom there is...

Homework Statement A concentric wire of resistivity ##\rho##,length ##L## has an inner radius ##R_1## and outer radius ##R_2## and charge density ##\lambda##. A current ##I## flows down the inner wire while the outer conductor is grounded, ##V=0##. a) Calculate the potential difference...

Homework Statement A current I carried in a conduit as described below. The wire can be assumed to be infinitely long in the positive x-direction. The point P is the radius distance a from the portion of the line that describes a semicircle. Calculate the resulting magnetic field at point P...

When I studied special relativity for the first time, I encountered the exemple of a infinite neutral wire in the laboratory frame of reference, R, through which a constant current is running. In this frame of reference, the electrons in the wire are moving with a velocity +v and the ions...

Hi all, I'm trying to do something that might be impossible, but seems to me should have a solution: Finding the height (or displacement) of a long, thin rod or wire under horizontal compression forces at the ends (pinned, not clamped) causing it to bend into a stable arch-like shape given...

I found a funny video on youtube, but I am not totally convinced by the argument. It says that a pure magnetic field caused by a current in a wire can lead to a combined electric + magnetic field in a moving frame. It explains more or less convincingly that this can be understood as a...

Homework Statement I need to know what effect wire heating would have on the reading of the EMF of a battery, and how the heating effect can be reduced! Homework Equations V= IR The Attempt at a Solution Well I know that the heating effect increases the resistance in the wire...

Homework Statement Part (a): Describe what happens to current when ring contracts Part(b): Find how much energy is stored, changing per unit time and rate of mechanical work being done Part (c): Show the pressure is given by: Part (d): Why is the force on a small wire segment not BIL...

When one comes across the sentence 'axis of a straight wire', how can one consider the orientation of the axis? Commonly, the axis of a straight wire can be considered to be a line parallel(along the wire) to the wire itself. Can 'axis of a straight wire' also mean a line that is...

Hi, I recently came across the idea that relativity can play a role in the repulsive force of a charge outside of a current-carrying wire. The situation described was when a positive charge (q) moves at the same speed and direction as the drift velocity of the electrons in the wire (assume...

I have read in my schoolbook that when a wire of length l moves at velocity v in a magnetic field cutting the flux lines an emf is induced which it is calculated from emf = blv, I understand that emf is induced at time variation of magnetic flux across the wire, but I Can't see any change in the...

Magnetic Flux= BA is A the surrounding area affected by the flux or the area of the coil itself that is affected by the flux

Hi there, Is it true that the magnetic field of a straight wire is the same when the charges are moving at low speeds (v <<c) as when they are moving at relativistic speeds (v~c). The extra relativistic factor the magnetic field gets from the moving charges cancels upon integrating. According...