Wires Definition and 543 Threads

This may be an obvious question but I have no idea: How can anyone link current-carrying wires (solenoids) and its formulae, to magnets?! All I've researched so far points out that magnets have their own stable magnetic field, attributed to the alignment of spins of the electrons of the atoms...

Can direct current running in opposite directions in parallel wires increase the apparent resistance of a system? This is a real life problem that I’ve noticed on some electroforming equipment we relocated. Prior to the move the wires were separate. Now they are located in a conduit...

Homework Statement Two long fixed parallel wires, A and B, are 10cm apart in air and carry 40 A and 20 A, respectively, in opposite directions. Determine the resultant field (a) on a line midway between the wires parallel to them and (b) on a line 8.0 cm from wire A and 18cm from wire B (c)...

Homework Statement Consider 2 parallel wires with currents running down them in the same direction. The first is fixed in place unable to move. The second is allowed to move. They exert an attractive magnetic force on one another, and the second wire moves towards the first. The second moves...

I have a homework question that I am having some trouble with. This is my first post - so be easy on me. Question: A weight-lifter is able to hold a barbell with a maximum total mass of 205 kg above his head. A physicist uses him to conduct a classroom demonstration, asking him to hold one...

Homework Statement Two parallel wires, each carrying a current of 2.2 A in the same direction, are shown in the figure . Find the magnitude of the net magnetic field at points A, B, and C. Homework Equations B=(μ*I)/(2*pi*r) μ=4*pi*10^-7 The Attempt at a Solution I believed I could simply...

Homework Statement The attached figure shows, in cross section, two long parallel wires that are separated by distance d = 18.6 cm. Each carries 4.34 A, out of the page in wire 1 and into the page in wire 2. In unit-vector notation, what is the net magnetic field at point P at distance R =...

Homework Statement Consider two parallel conducting wires along the direction of the z axis as shown below. Wire 1 crosses the x-axis at x = -2.60 cm and carries a current of 2.00 A out of the xy-plane of the page. Wire 2 (right) crosses the x-axis at x = 2.60 cm and carries a current of...

[b]1.Hey guys, I've been struggling with this one for an hour and it SHOULD NOT be this hard for me. A 15kg picture hangs from a hook on the wall. What is the tension in each wire if one is at a cartesian angle of 220° and one is at a cartesian angle of 320°? [b]2. So my physics...

Hello, a beginners question here. Can someone please tell me why transmission lines use two wires instead of just one ?

Homework Statement Three infinite straight wires are fixed in place and aligned parallel to the z-axis as shown. The wire at (x,y) = (-21 cm, 0) carries current I1 = 2 A in the negative z-direction. The wire at (x,y) = (21 cm, 0) carries current I2 = 1 A in the positive z-direction. The wire...

1. Homework Statement 9 V battery is connected to wire made up of three segments of different materials connected in a series: 10 cm copper, then 12 cm iron, then 18 cm tungsten. All wires are 0.26 mm diameter. Find potential difference across each wire. Constants: p Copper= 1.7 x...

Homework Statement Three infinite straight wires are fixed in place and aligned parallel to the z-axis as shown. The wire at (x,y) = (-23.5 cm, 0) carries current I1 = 3.3 A in the negative z-direction. The wire at (x,y) = (23.5 cm, 0) carries current I2 = 1.2 A in the positive z-direction...

Homework Statement Consider a general point on the line joining the two wires and a distance d away from the mid-point O. By summing the magnetic field due to currents of magnitude i flowing in both the wires which are non-zero, show that on the line joining the two wires, the magnetic field...

Thanks. Why do wires get hot as current flows? Is it friction?

Homework Statement There is a 104kg uniform log hung on two steel wires, A and B, both of radius 1.00mm. Initially, wire A was 2.70m long and 2.00mm shorter than wire B. The log is now horizontal. Note that the centre of gravity (com) is not necessarily centered between the wires and the...

I'm doing A-Level physics and I've been answering questions on Young's Modulus. I need to be able to explain why a long, thin wire is used when measuring the Young's Modulus of a material. I can give an explanation of why stress due to the wire being thinner is greater but I don't know why...

Homework Statement two parallel wires 20 cm apart carry currents of 16 A in the same direction.what is the magnetic field halfway between them? why is this so? Homework Equations The Attempt at a Solution

Homework Statement A uniform 165 N bar is supported horizontally by two identical wires A and B. A small 185 N cube of lead is placed 3/4 of the way from A to B. The wires are each o.75 m long and have a mass of 5.50 g. If both of them are simultaneously plucked at the center, what is the...

Homework Statement I have 2 infinitely long parallel wires each carrying a charge of 1 amp in the same direction, and I have to find the magnetic field at a specific point in between them, and I know the distance to it from each of them. Homework Equations This is what I'd like to know...

I'm just studying past exams for my physics exam in a few days. I've been struggling with this question http://img823.imageshack.us/img823/7469/45633341.jpg The first thing i did was use the Biot-Savart law to find the magnetic field at z=0, or at ±d/2 away from z=0 I found the...

Homework Statement The point p is located at (3,1,2). An infinitely long straight wire passes through the points (0,0,0) and (0;1;0) and carries a current of a A in the positive y direction. A finite length of wire carries a current of b A from (2,0,0) to (2,0,0). An semi-infinite solenoid...

I don't know what i did wrong Find the tension in the two wires supporting the traffic light Mass of light= 33 kg θ of FT1= 53° θ of FT2=37° Ʃfx=0 Ft1cos53-ft2cos37=0 ft1cos53=ft2cos37 Ʃfy=mg ft1sin53-ft2sin37=mg ft1sin53=mg+ft2sin37 ft1=(ft2sin37+mg)/sin53 ft1=1.33ft2...

Straight wires carrying DC currents... Dear Forum, when will two straight wires, both carrying a DC current, not feel any mutual magnetic force? What reciprocal orientation do they need to have? It looks to me that they will always feel a magnetic force if they are parallel...

Homework Statement a uniform horizontal steel beam of mass 35kg and length of 5m is supported by two vertical cables. the first attached at the left end and the second 1m from the opposite end. find the tension in the cable on the right. Homework Equations n=mgsin0 The Attempt at...

[url]g4ph-h7l_aM[/youtube] This is pretty old but it just crossed my mind. Wanted to share it with you guys. One question though, why is that current arc going upwards? And why did it appear at all? Can we discuss this effect?

Homework Statement Two thin, long wires situated in y = -a and y = a carrying two equal in magnitude and opposite running currents I. Find the field strength in therms of y. Find the average Field strength in a region -b to b, where 0 is between the 2 points. Homework Equations Amperes...

Homework Statement I am trying to figure out how the formula for the force between two anti-parallel wires differs from the formula for parallel wires. Homework Equations B=μ0I/2∏R Force between two parallel wires = μ0LIaIb/2∏d The Attempt at a Solution I understand that d is...

I'm just curious why solenoids used to create a magnetic field, such as those used in electric motors are typically coils of thin copper wires with a dielectric separating each turn of wire instead of using a single cylindrical shell made of solid copper. Wouldn't using a cylinder shell made...

Homework Statement http://i.imgur.com/EHokd.png Two long wires carry currents I1 and I2 as shown in the figure. The first wire runs parallel to the x-axis but is a distance d above the x-y plane. The second wire lies along the y-axis and passes through the origin. What is the...

Two long straight thin conducting wires run in parallel. The distance between them is d and the length of each wire is l. One of the wires is charged with charge +Q, the other wire with charge -Q (a) Calculate the strength of the electric field E(Q; d; l) generated by one wire at the...

hye... i new user (forumer)... help me... 1) i have 3- 4 piece wire (copper/ iron)... i don't know AWG for piece wire... no label... the length of wire is 1 foot... how to know / measure / calculate the maximum voltage, maximum current, maximum temperature, thickness, type of metal for...

Homework Statement The metal rod in the figure moves with speed v parallel to a straight wire that is carrying current I. The distance between the two wires is d, as shown in the figure. If the end of the rod closest to the wire is chosen to be at zero potential, what is the potential at...

Homework Statement There is a coil placed on a very sensitive weighing scale that has a variable resistor attached it to control its current, and is also connected to a power supply. The wires to it have tape to hold them in place. There is another coil held a few millimeters above this coil...

Hi there, I'm a student in high school. I'm quite new to the forum. Please forgive my mistakes. Homework Statement My question is related to electricity, more specifically the factors affecting resistance in a wire. I know that resistance is inversely proportional to the cross-sectional...

Homework Statement Using conductivity constant (q=1.45*10^6mA) deduce the cross-Sectional area of the wire from the slope of the Data found in the graph. Voltage was kept constant 1.00 volts The wires are each 1m long After graphing the data the Current(mA) # of parralel lines 121.4...

Homework Statement Attached in picture Homework Equations N/A The Attempt at a Solution for What will happen if you cut the wire at position B? I think The light bulb will become dimmer, but not go off. Am I correct? for What will happen if you cut the wire at position D...

Homework Statement Two parallel wires carry current in same direction. Do they attract or repel each other? Homework Equations Magetic field (B) created around wire. Direction using Right Hand Rule. F(mag) = I(L x B) The Attempt at a Solution When I work out the...

I install and repair coffee and espresso equipment and we sometimes run into electrical problems beyond my knowledge (well versed in household wiring, good with fundamental applications of ohms law, etc. but I'm no physics major!) The issue that comes up most often is dubious grounds, or...

Homework Statement A) Find the magnitude of the net magnetic field at point P and point Q B) Reverse the directon of the current for the wire on the x-axis Homework Equations B = μ0I/2πr The Attempt at a Solution Solution attempt attached. Only attempted part A, since I probably won't get...

I read on Kraus' "Electromagnetics", 4th edition (p 583), that four-wire transmission lines (in a quadrupole configuration - the conductor with the same polarity are in diagonal) improve shielding. + - - + I tried to find some more information about this sort of transmission lines but...

consider two wires of different diameter. when current enters from that of greater diameter to lesser diameter drift velocity increases. which force causes it to increase?

Homework Statement Because of the 2 wires in the figure, For what value of the ratio I1/I2 is the magnetic field zero at the point A? point B? point C? Homework Equations http://tinypic.com/r/5otweg/7 The Attempt at a Solution I honestly have no idea where to start with this problem, any help...

Homework Statement http://i.imgur.com/mgIkS.png Two long parallel wires carry currents of 2.03 A and 8.83 A. The magnitude of the force per unit length acting on each wire is 4.49*10^5 N/m. Find the separation distance of the wires expressed in millimeters. Homework Equations I'm not...

Homework Statement Homework Equations The Attempt at a Solution Is this the correct equation to find the current (I)? I setup a free body diagram for bar 2, TCos(24)-(.036kg)(9.8m/s^2)=0 (for y) -TSin(24)+ (Eqtn for force between two parallel wires but with the current squared) (for x)...

A simple electric circuit (such as one composed of a battery with Emf V and resistor with resistance R) is in an electrodynamic state since the battery's potential difference creates an electric field in the circuit's wires, which in turn moves charges around. So potential difference in wires is...

Homework Statement Two very long, straight, parallel wires carry currents that are directed perpendicular to the page as shown in Figure P30.9. Wire 1 carries a current I1 into the page (in the -z direction) and passes through the x-axis at x = +a. Wire 2 passes through the x-axis at x = -2a...

can i empty a wire from its free electron.

Homework Statement see attached. this question is from a test that doesn't allow any calculators and usually makes students solve the problem in 1 minute max. Homework Equations perhaps biot savart is to be used? but I doubt that can be done in the time limit... The Attempt at a...

Homework Statement If there are two long straight wires that are 6cm apart. If I calculated the magnetic field strength at a point between the wires, which are 4cm from one wires and 2cm from the other and B= 8x10^-6 T Sketch a graph if the variation of the magnetic field along a...