Assuming the same wire materials, which has the greater resistance: a single wire, or a bundle of wires with the same length and diameter as the single wire?
213626
If the bundle diameter is the same and the individual wires are round in cross-section, then obviously the area of wire metal in the cross section is less in the bundle than in the solid wire so the bundle has a higher resistance. But let's say you mean that the bundle is enough larger in diameter that the metal areas of both cross sections are equal as assumed by answer 2. Suppose there are N strands in the bundle and the solid wire has a resistance R. Then each strand's resistance is N*R. Contrary to answer 2 (if I am reading it correctly), it makes no difference if the individual wires are connected side-by-side or not, as long as they are connected together at each end. Connecting them thus in parallel makes the bundle's resistance equal to R. Since the strands are identical in resistance and therefore carry the same current, the voltage at any distance along one strand is exactly the same as at the same distance along any other strand. Connect them together at that point and what happens? No change in current flow because no change in voltage, and therefore no change in resistance.
11546
increasing thickness, decreasing temperature, and decreasing length would all reduce the resistance of a metal wire. so the only thing that reduces it by increasing is thickness.\n\na good way to remember this is just to reason it out. if the wire is thicker, current can move more freely and with less resistance then a thinner, more constricted wire. the electrons in the current would have more space to move around.  if you increase temperature, it would cause more resistance, because with temperature, comes heat, and heat just makes more resistance. lower temperatures allow the current to move more freely, which is why superconductors work really well at low temperatures. and length, well the longer the wire is, the more the resistance is going to build up along the whole thing... the electrons are just encountering more resistance because the wire is longer..
104677
Georg Ohm formulated the relationship between voltage and current in a conductor (resistance). See the source for details.
626479
Hi,\n\nCarbon composition resistor is made of carbon granules mixture.\n\nCompared with other resistors, carbon composition resistor also has lower cost and wider resistance range in general than many other resistor types.\n\nYou may refer to this page to know more.\nhttp://www.kodkodkod.com/files/carbon_composite_resistor.htm\n\nKodKodKod Learning Consulting\nhttp://www.kodkodkod.com/index_files/submitquestion.htm
481709
1. C\n2. C\n3. A  \n4. B\n\nnote: The resistances are measured in ohms, not kW.
427652
The resistance of the filament will increase as it heats up. So you're going to get something called a "transient", which is when the initial value will stabilize (to the working current in this case), after a period of time.\nA lower starting resistance equals a higher starting current.
29612
Hmmm... good question... exactly what are you trying to do?\n\nMaximum current would depend on the gauge, type, and quality of wire used to make the cable.  Not all cables are made the same... some are higher quality and provide better transmission distances while others are generic, cheap, and won't handle the same load.\n\nIf you're an electronics person... it's kinda like comparing copper to aluminum... so the answer would be... it really depends on your cable...\n\nLater!
41597
Well, the easiest way is to get some wire, wrap it around a iron/steel rod, and apply a current to the wire.\n\nTo get an electromagnet to have a lifting capacity that you specified, it will require a little more engineering work.  Trying to stay in the most basic terms, the power of your magnet will depend on how much current you put through the wire, how many turns you have around the iron rod, and something called the magnetic permeability of the iron rod.  Now there's some trade-offs with all of these factors.  More turns increases the magnet flux (strength), but requires more wire and increases the resistance.  More resistance means that you will need more current to counteract this problem.  Treating your electromagnet strictly as a resistor (which it is not), by following Ohm's law, you increase the current by increasing the voltage.   Too much current and you may end up melting your wire.   You want to keep the wire as small as possible so that you can get the turns as close as possible to your iron rod, but smaller wire has a higher resistance and lower current carrying capability.\n\nIt's a matter of balancing a lot of equations to get the best combination.  Your best bet is a little trial and error.
267033
I am sure there is, that's why we had to learn the geometry and algebra.  I am sorry I don't know what it is.  I would bet it has to do with the weight of the load depends on the type of cable you would use and amount of cable depends on the volume of the load...see?
510480
Convert all this to MKS units and find the cross-section of that wire.\n\nE (stainless-steel) is given to be 18 x 10^10 N/m^2.\nCross-section is from pi(r^2).  This must be in m^2, not mm^2.\n3.14159(0.125*10^-3 m)^2 = 4.909 x 10^-8 m^2 cross-section.\n\nYoung's modulus (E) is given as,\n\nE = (delta F / cross-section) / (delta length / original length)\n\nDelta F is the tension in the wire, thats the first part of solving this problem.  So rearrange the equation for delta F, renaming delta F as "tension" and substitute the value given in place of E:\n\nTension = (18 x 10^10 N/m^2) * (8 x 10^-5 m / 0.028 m) * (4.909 x 10^-8 m^2)\n\nTension in the wire is therefore 25 N.\n\nThe magnitude of force on the tooth is 25 sin 30 deg or 12.5 N\n\nWarning!:  While the reasoning is sound, double-check all of my math.  Also, note that I rounded the intermediate answer 25 N.
332039
I believe Volt is just the name of the unit for EMF, like meter is the name of the unit for length.
505141
Like everything else, it depends.  The concern is that at the maximum current you will draw, there is sufficient voltage at the point of use.  Voltage drop depends on the amount of current, and the resistance of the circuit.  \n\nYou can determine the minimum voltage requirements for whatever you are driving.  Knowing the resistance per foot of various sizes of wire, you could determine the size wire needed.\n\nNow it becomes a matter of economics.  Is larger wire less expensive than a transformer--or two if you are going to maintain the original equipment operating voltage.
197003
Standard copper coaxial CABLE TV wires use a drip-loop to compensate.\n\nThe drip loop is approximately 12 inches long, so the wire probably doesn't move more than six inches.
550600
Make sure you have a good, solid connection between your sample and your ohmmeter probes.  Use a scale on your meter that's appropriate for the resistance you are measuring.  If your resistance is 1/2 ohm, then it will read zero on a 0-20Kohm scale, which isn't useful.  It will read half-way on a 0-1ohm scale, where you can get a good reading.\n\nThe resistance of a sample depends not just on the material and temperature, but also the geometry.  The resistance of a uniform wire will be proportional to its length and inversely proportional to its cross-section area.
391153
Trick question... all things regardless of weight fall at the same speed. You need to know how big the item is first... this is the only way to calculate resistance.
174120
A conductor is a metal such as copper. The outer elctrons of the copper atoms are shielded by the inner shells of electrons so these outer electrons tend to easily move between and around the copper atoms. If a potential is applied to a piece of copper wire then it's these excess electrons that create a current flow in the wire. The is the property of a conductor.\n\nAn insulator on the other hand is formed from atoms that have strong bonds to the outer electrons of each atom. When a electric potential is applied then nothing happens as the atoms won't provide anything for electrons to flow. Silicon and oxygen atoms bonded together make good insulator.
391466
The length of the wire must be (2x5)+(2x7)=24cm.  So each side of the triangle must be 24/3=8cm. long.