What is Cables: Definition and 172 Discussions

Networking cables are networking hardware used to connect one network device to other network devices or to connect two or more computers to share printers, scanners etc. Different types of network cables, such as coaxial cable, optical fiber cable, and twisted pair cables, are used depending on the network's physical layer, topology, and size. The devices can be separated by a few meters (e.g. via Ethernet) or nearly unlimited distances (e.g. via the interconnections of the Internet).
There are several technologies used for network connections. Patch cables are used for short distances in offices and wiring closets. Electrical connections using twisted pair or coaxial cable are used within a building. Optical fiber cable is used for long distances or for applications requiring high bandwidth or electrical isolation. Many installations use structured cabling practices to improve reliability and maintainability. In some home and industrial applications power lines are used as network cabling.

View More On Wikipedia.org
  1. O

    Phase Arrangement of Parallel Medium-Voltage Cables

    Hi If the length of parallel medium-voltage cable runs is approximately 20 meters, and cable sheath is grounded only at one end, does it matter how the parallel phases are installed on the cable rack? If the straightforward installation method doesn't follow the rule for arranging the phases on...
  2. S

    Motherboards that can transmit audio over video cables

    Are there motherboards for desktop computers that can transmit audio over DVI or HDMI cables to a TV when the TV is used as the computer's display? If so, what terminology is used in the specifications for such a motherboard to indicate this capability? For example, the manual for a Samsung TV...
  3. A

    I Light coupling in fiber optic cables

    Hi Everyone! I have a photonics problem that I was wondering if anyone may be able to shed some light on (no pun intended). I work for a company that is designing a fiber optic emitter/detector as a part of one of our products and we've noticed something that would appear to defy physics...
  4. C

    Markov processes (Weight Suspended equally by n Cables)

    Summary:: Markov processes (A weight of L tons is suspended by n cables which share the load equally) A weight of L tons is suspended by n cables which share the load equally. If k, for 1 ≤ k ≤ n − 1, of the cables have broken, then the remaining (n − k) cables share the load equally. As soon...
  5. Oldman too

    Dark fiber optic cables as Earthquake detectors

    Hello, Recently while familiarizing myself with the rodent menace affecting Fiber optic networks, I came across this rather novel use for the dark, or unused fibers in buried cables. The method apparently holds a lot of promise as well as significant advantages over many current Seismology...
  6. Lay1

    A boat being pulled by two other boats with cables

    FAx = F cos 40 FAy = F sin 40 2FAx = Drag Drag = 6128N The answer says 6200N
  7. K

    What are these DWV pipes with cables inside for?

    The main floor is an office. The second floor might be an apartment.
  8. A

    Force on two cables holding a liquid-filled container against a wall

    Before, sorry for my English, it is not my native language I already have the solution to the issue, I just didn't understand a step. 1) Calculation of weight force (vertical): $$ F_v = \frac{\rho \pi R^2 . L .g}{4}$$ 2) Calculation of force due to water pressure on the plate (horizontal)...
  9. QuentinChe

    Voltage detection in electrical cables

    Hello guys! I am a student who currently works on a project based on electrical detection and voltage measurement in electrical cables remotly. So in order to accomplish my work, I'm seeki ng for new ways to detect voltage. I already have some ideas such as using magnetic fields or measuring...
  10. Camailee

    Engineering Statics problem: A ramp is supported by two cables

    Problem illustration: The possible answers are: I don't understand why it says Mc if it is asking for the moment at A, not C. But maybe I am getting something wrong. So with the formulas I posted above, I have this:
  11. Y

    Question about USB and using long USB cables

    Hi I have not been keeping up with the latest USB standard, is the latest one USBIII? What is the speed of this? Also, I want to run a USB cable at least 4m long, do they have USB cable that long and still work for the fastest USB standard? I know in the past, even for USBII, there is a...
  12. M

    KiwiSDR and recommendations for antennas and cables

    I recently bought a KiwiSDR and it's my first SDR so far. I was wondering, what antennas you guys recommendation for it and whether this recommended antenna is truly good for it (it was listed on the KiwiSDR site as a recommended antenna, but it's a bit pricey for me). I'm trying to find signals...
  13. TechTree

    Electrical interference on data cables

    Hello, I've got two computers that are in separate rooms and I have placed plastic conduit through the small space above the ceiling. Which will have a USB data cable, an Ethernet network cable, and a HDMI cable inside. The conduit length is about 8m long. And I was wondering if this setup could...
  14. WOLFY302

    Finding the tension of two cables holding an object at rest

    A 30 kg sphere is held stationary by two cables. One cable is attached at 60° above horizontal. The second cable is horizontal and attached at the side of the sphere. Find the tension in both cables. Newton's 2nd law: F=ma, which means a = (∑F/m) We can also find the weight: W = mg Let's say...
  15. T

    Why is a beam supported by two cables more stable than one?

    Imagine a steel I-girder lifted by a single wire rope. If the rope is not perfectly centered along the girder length, the girder will rotate about a horizontal latitudinal axis through its centroid. Imagine a girder pair lifted by two wire ropes, with one rope on each side of the girder...
  16. Casper Hansen

    Accelerated lifetime / thermal ageing of power cables

    Hi PF Is it possible to perform accelerated lifetime test of thermal ageing on power cables? Let's assume that the cable manufacturer guarantees a service life time of 20 years at max operation temperature 90 [degC]. Is it possible to estimate the expected life time of a cable if I choose to...
  17. K

    Basic mechanics question -- Two cables supporting a stage light

    Homework Statement Homework Equations [/B] apparently noneThe Attempt at a Solution [/B] Hi, this is a question from the OCR for self studying purposes. Only the first question is relevant for me. I know that the solution is 120N in the opposite direction to the weight, but i can't get to...
  18. jonnybmac

    Why Do Tensile Cables Differ in Thickness?

    Homework Statement Why are cables thin when used as ties? Why are they not equally as thick as say struts? Homework EquationsThe Attempt at a Solution Is it because when in tension the tie cannot buckle? or because when in tension it cannot shear? Steel has the same compressive strength as...
  19. F

    Ionized Gas Cables: Can You Buy Them?

    Hi! Does it exist cables using ionized gas / plasma as the conductor available to buy? Thanks in advance!
  20. F

    Prestressed concrete - tension in steel cables

    Hello Everyone, I was learning about prestressed concrete and how it works. Concrete is very strong under compression but weak under tension. In the case of prestressed concrete, the steel bars are pulled and become elongated. How much do the steel bars elongate when they are pulled? The...
  21. O

    Vertical cables in a suspension bridge

    Homework Statement Problem 5 here: http://www.princeton.edu/~romalis/PHYS203/HW1.pdf Homework Equations N/A The Attempt at a Solution The part that really confuses me is where it says that the cable lengths are adjusted so there is no shear stress on the bridge. What exactly does this mean...
  22. A

    Selection of multi-pin connector for power lead cables

    Hi, I have 6 cables. Each cable has 3 wires: zero, phase, earth. Each cable supplies 320W 230VAC heater (I have 6 heaters). I am looking for 1 multi pin connector for all these cables for quick plug in/out. Link to example connectors...
  23. D

    Temperature related to Current flow on BBr or cables

    Temperature with hot spot by Ir thermal cameras of modern development is being used for measuring on the object of terminal surfaces and cable working temperatures in particular working loads. However, so far no measurements has been designed to obtain the result on the flow of current...
  24. U

    Force on 2 cables with weight attatched using Theta....

    Homework Statement https://ibb.co/g6iKDQ Calculate the magnitude of the force on cables 1 and 2 in the figure below if θ_1 = 55° and θ_2 = 35°. (Round your answers to two decimal places.) Homework Equations Is my method incorrect or did I go wrong somewhere in my calculations?? The...
  25. T

    Displacement current in coaxial cables

    To calculate the displacement current in a coaxial cable (with equal and opposite currents on the inner and outer conductors), most standard texts use the magnetoquasistatic approximation, which ignores the time-varying electric field term in Ampere’s Law. Using this approximation, the...
  26. P

    Efficacy of Balanced XLR Cables for Noise Reduction

    When attempting to find an answer to the "quality" of sound one attains from various audio cables, most of the research leads to the very subjective answers of audio/sound engineers. I was hoping to gain some insight from a physics/engineering perspective. I'm curious if an expensive or...
  27. heartshapedbox

    Find tension in cables supporting giant swing

    Homework Statement Picture a seat that is supported by two cables. One is horizontal, and the other makes an angle of 40 degrees to the vertical. The swing swings in a horizontal circle at a rate of 32 rev/min. The horizontal cable is 7.5 m long. The person sitting on the seat at the end of the...
  28. T

    Impedance matching between two 50 ohm cables through a joint

    Hi, I'm in a bind trying to determine how to handle impedance matching through a joint of copper wire sandwiched between two 50-ohm coaxial cables (the joint is an interface between atmosphere and a UHV system). There is a signal pulse with a rise time of 2 ns coming through one of the coaxial...
  29. shaft

    What happens if I connect the electric cables in this way?

    If I have a light bulb that take energy by the normal current of the house but I want connect at the bulb an other part of energy from an other source of electricity but with an inferior Voltage. This circuit will work or no. How to connect the second source of energy to reduce the amount of...
  30. amrmohammed

    Self-regulating heating cables low power output

    Hello, Why do self regulating heating cables have such low power output per foot? Power output in these cables does not exceed 20 W/ft at 10 degree C, and decreases as the temperature goes up. Many of the cables I saw can withstand high temperatures (250 degree C power off and 150 degree C...
  31. P

    Electric Fields in Coaxial Cables: Understanding Bound Charge Densities

    Homework Statement http://postimg.org/image/vzhqi8er5/ Homework EquationsThe Attempt at a Solution I understand all the calculations here - http://www.physicspages.com/2012/10/18/coaxial-cable-with-dielectric/ I have one issue that is bugging me though - if λ charge density is distributed over...
  32. A

    Maximum weight a bar and cables can hold before breaking

    Homework Statement A weight W is supported by bar AO and cables AB, AC, and AD. Point A lies in the xy plane, if the bar and cables have the strengths listed below, determine the largest value W may have. Hint given: A FBD of joint A is recommendedto being this problem. Bar AO should be...
  33. I

    Optics Question -- small glass spheres to couple to fiber optic cables

    Homework Statement Homework Equations I know that yin = 0.7mm, y2 = 0mm, the index of refraction for the sphere is 1.8 and the indices of refraction for the air surrounding it is 1. The Attempt at a Solution Not sure how to even begin with the given information. I was thinking I could...
  34. amrmohammed

    Why Mineral Insulated Heating Cables have power output limit?

    Hello Why does Mineral Insulated heating cables have such limited power output per feet and maximum operating voltages? I thought it has to do with the dielectric strength of the MgO, that is used as an insulation in the coaxial cable, but the dielectric strength for MgO is higher than the...
  35. R

    Splitting power between cables by rating

    How are power distribution cables parallel-ed to split loads optimally? If the cables were exactly identical this would be easy but how is it achieved in general? e.g. Say there's a 11 kV to 420 V distribution transformer but the primary load is some distance away. Assume the load increases...
  36. Guidestone

    Strange questions about electrical circuits

    What's up people? I'm new in this wonderful forum. I have several questions about circuits, and they are not really common, I mean, I find them somehow complicated, but I would really come to enlightenment if you guys gave me some clues. 1.- So, let's suppose we got the simplest circuit, a...
  37. A

    Voltage behavior in UG cables and OH 11 KV distribution lines

    i want to know the behavior of voltage in 11 KV underground and OH distribution line at different load conditions i.e. no load-full load ...
  38. M

    What are the tensions on two cables holding a girder hanging from a crane?

    Homework Statement There is a girder hanging from a crane by two cables. The girder is 2.6m long and hanging at an angle. The weight of the girder is 0.50 kN. Calculate the tensions of each cable. Homework EquationsThe Attempt at a Solution I would divide the two cables into their x and y...
  39. C

    Determining the forces in three cables.

    Homework Statement Homework EquationsThe Attempt at a Solution 1. I first found the angles each cable made with the pillar. 2. With these angles I found the components of the forces in the x and y direction. 3. So ∑Fx and ∑Fy were found. 4. Then using these values I equated...
  40. Greg Bernhardt

    AudioQuest Diamond: most expensive HDMI cables worth it?

    I was browsing amazon for some basic HDMI cables and was flabbergasted when I came across some by AudioQuest Diamond. They cost $1,494.75 for 6.5FT. https://www.amazon.com/dp/B003CT2A2M/?tag=pfamazon01-20 The information gives Solid Perfect-Surface Silver (PSS) Conductors Low Jitter, Low...
  41. J

    Solving Mystery Electrical Cables: Seeking Advice

    Hello all. I am not an electrical expert here, just know enough to wire basic things at home (i.e. switches, outlets, etc)...so please be kind. My situation is this. We recently bought a new house and have found a couple of mysteries. The biggest one is that there are several electrical...
  42. U

    Minimizing tension in the cables

    Homework Statement A heavy box weighing 25kN is to be lifted by 2 overhead cranes with cables inclined at 40° and 30° with the vertical respectively. i) Find tension in each cable during lifting. ii) Due to safety concerns, the tension T2 in second cable is to be minimized. Find the angle...
  43. J

    Static Equilibrium and tension of cables

    Homework Statement A 30Kg neon sign is suspended by two cables, as shown. Three neighbourhood cats (5.0 Kg each) find the sign a comfortable place. Calculate the tension in each cable with the cats are in the positions shown. Homework Equations xCM = m1x1 + m2x2 ...
  44. L

    Engineering Short circuit calculation small network: gen motor transformer cables

    Hello guys, I have to make a short circuit calculation for school but I am a bit lost.. I have a copy off the IEC61363 and internet connection as my help lines. Homework Statement The network consists of a generator feeding to switchboard A with a cable in between, on the same...
  45. S

    Force - gondola car suspended between 2 cables

    Homework Statement A car weighing 789 kg hang at an angle of 90°. What is the tension in each cable? The Attempt at a Solution (deleted answer)
  46. F

    Cables in tension passing through board with holes.

    Hey guys, I'm looking for examples of real life systems which uses a board with holes to redirect cables in tension (as opposed to pulleys) for some inspiration on a project I'm working on. I've attached an schematic of what I mean. I've tried searching google for systems but it's a hard...
  47. C

    Should optical cables be water tight? Geometric optics

    Homework Statement Explain the physical principle of total internal reflection used by optical cables. Calculate the critical angle of incidence that corresponds to a refracted angle θair = 90 Next, calculate the critical angle for a bare glass fiber submerged in water nH2O = 1.33...
  48. D

    Impedance Matching Coaxial Cables

    Homework Statement We need to connect two coax cables with the same dielectric (εr = 9) but with different dimensions as shown. How big must be the radius of the outer conductor of the second line in order to match two lines? How would the velocity of the wave propagation change, if we...
  49. A

    Calculating Tension in Cables: 1000N Beam with 2000N Filing Cabinet

    Homework Statement A 1000N beam is loaded with a 2000N filing cabinet and supported by two cables. If the beam is 8 meters long and the filing cabinet is 2 meters from the left cable, what is the tension force in each cable? Homework Equations T= F /d The Attempt at a Solution For...
  50. EVriderDK

    Calculating voltage drops in cables with vectors?

    Hey. If i Have a 3x400VAC system, and I want to calculate the voltage drop over the cable "vectorially" - or what you call it :) - how do I do this? U.nominal=400V I have tried this method: \DeltaU.conductor=I.1*Z.cable1+I.2*Z.cable2+etc. and then I will have to find the new voltage ->...