Why do we hear a metallic sound beneath overhead high tension (voltage) transmission wires (e.g. 133,000 V)?
152209
wind. the speed of the current traveling through the lines. when they pass each other they make contact.
424835
(m)\n\nIn large computers, neutral to ground voltages are originated because nonlinear currents flow through the neutral wire. In general always when there is some current flowing in neutral wire, there will be a ground ot neutral wire voltage difference on output end, because there is no current flowing on ground wire. In some computer systems the voltage differences are considered to be problem, because it has been reported to cause cause improper behaviour like "hangouts" on some computer systems. \n\nIt is true that in some special cases neutral to ground voltages can cause this kidn of problems, but in those cases it is not to blame the separate wires, because the problem lies in some other place. In properly built electrical wirign network, the neutral to ground voltage differences will never be more than few volts and any properly designed electrical equipment should not be disturbed of this kind of small voltage differences. \n\nIf the equipment gets disturbed of this small main frequency voltage, claim the manufacturer/designer of that particular equipment for doing bad job. Computer equipments can be easily deigned to cope few volts of voltage differences between neutral and ground. Most of the modern euquipments are designed to cope this. \n\nIf the voltage difference between your neutral and ground is much larger than few volts or there is very good propability that there is somethign wrong on you main wiring. So it is best that an electrician goes and checks your wiring before more problem and damages happen. \n\nIn some cases the neutral actual to ground voltage is not the problem, but the wavefor of the voltage. Non-linear loads like computer power supplies and light dimmers can cause some considerable noise between neutral and ground. Such noise can be more problematic than just a simple voltage difference, but equipment should still be able to cope quite fair amount of it (EMC regulations etc.). If you have considerable amounts of noise on neutral wire used by nonlinear loads, then you can again blaim the improper design of the electrical wiring. This kind of problems can be solved by good wiring design practices: separate electrical wiring from main panel/transformer to the equipments which cause noisen and to equipments which are sensitive to it. This is good practice and keep problems away. \n\nIf you would have on those cases had a wiring with common neutral and ground wire, you would have terrible ground potential diffeences between different outlets. In cases were ther problems neutral to ground voltage differences in separate ground and neutral wire wiring start cause problem, a wiring with common ground+neutral wire there would be so much ground potential differences between outlets that any equipments connected to different electrical outlets and interconnected would work very erratically, you would propably cause many equipment damages. Computer sustems are generally much more sensitive to the ground potential differences than ground to neutral differences. \n\nThe bottom line is that separate ground and neutral wire is a good thing for many problems. It solves more problems that what it potentially causes. And in wery rare situations where separate ground and neutral wires cause some problems, in those same situations a wiring with connon neutral+ground wire would have caused much more but different kind of problems in form of ground potential differences. When taking account situation where computers are interconnected/networked, a good stable ground potential for aal equipment is much more important than very small neutral to ground potential. Separate ground and neutral wires is a good method to keep the outlet grounds at same potential, which is very important in networked computer systems.
616514
Generating static electricity.
197303
Transmission of electricity can be likened to "transmission" of water where voltage is equivalent to water pressure and electric current is equivalent to water flow.  For a hydraulic car lift you can get the same power (lifting force) using low pressure (voltage) with a large cylinder (line) or high pressure with a smaller cylinder.  For that reason a high voltage transmission line needs to carry less current for a given power than a lower voltage line.  It is the current and not the voltage that heats a wire and the transmission lines must be sized to pass needed current without too much heating.  I believe that power companies can reduce voltage and increase current to slightly heat the transmission lines to avoid icing (and weight) during winter storms.\n\nYou can safely grasp a 110 Volt insulated electric cord, but ordinary insulation would not prevent high voltage from arcing through the insulation (it would break down a path) and electrocute you.  Therefore High Voltage lines are not insulated but are instead supported by large non-conducting ceramic insulators to hold the conductors far enough from the towers to prevent arcing.  There may be a separate wire above the high voltage transmission lines to arrest lightning strikes.
1037287
Most traffic light intersections have a magnetic strip to detect if a vehicle is at the light.  Some are stronger than others so there could be a big variation.  This magnetic force could be interfering with your radio.  You can go to Radio Shack and get a noise limiter for your radio to reduce or even stop the static noise.
199036
Current burns, voltage jerks the muscles.  Too much current, you're toast.  Too much voltage, your heart stops.\n\nStatic built up from rubbing your socks on the carpet probably won't kill you.\n\nSeveral years back, in the wintertime, there were some news reports of people whose car blew up at the gas pumps.  Supposedly it was due to static electricity.\n\nIt's rare to get "shocked" outside when getting in or out of one's car or touching it or whatever but it does happen.  I remember a couple times in the past 5 years when it happened to me. A tiny percentage of times I have done that but way more than zero.\n\nSo, I guess the combination of a spark and being by your open gas tank could kills you, indirectly.\n\nTaking an extreme counter-example, there was a girl struck by lightening at the WHFS alternative rock festival in DC a few years ago. Apparently it knocked her a few feet from where she was standing.  But, it didn't kill her.  She was lucky.\n\nStatic charges build up more easily in wintertime. The air is dryer.  Something about the air molecules is different when there is less moisture.  I forget what, but you have probably noticed more "static" shocks in winter than any other time of year, unless you live in a really cold, dry place.\n\nA three inch spark seems pretty far.\n\nIn high school physics class, they said that each inch that a spark travelled off a sphere through the air indicated 10,000 volts.  I think it was 10,000.  Well, you're not a sphere and you are probably not touching one but that still seems like a lot.\n\nI used to get shocks of half or three quarters of an inch  when touching the corners of walls at the house I grew up in all the time.  That was really nothing.  I barely felt it.  It was just a surprise to feel it, and also to see the spark leap between the wall and your finger.\n\nModern buildings have grounding wires on all the outlets and stuff like that, to prevent electrical problems.  Not sure what really old buildings are like.\n\nIf you are wearing a sweater or wool clothing, that could increase the amount of static charge you build up.  There are all kinds of things that could do it.\n\nIf it happens on warm, humid days when you are not wearing any wool or sweaters, that would really be strange.  If not, maybe it is what you are wearing or the atmosphere that is mostly responsible.\n\nAlso, carpet is a big factor.\n\nFeeling it hours later, that's freaky. That never happened to me.
466747
touch a metal which is well grounded.
103937
Static electricity is caused by friction. When the air is dry like in winter there is more friction.
420016
No. All such high towers are normally equipped with a an anti-lightening device, that grounds (or earths) any negative ions in the air around it, before it causes lightening. In a way, you can say it diffuses lightening, the same way a leaked live wire is earthed by the third pin on the socket before causing shock.
391194
I'm assuming you talking about CAT5 or twisted pair cabling. When current runs down a wire a magnetic field is formed introducing noise into the line. By twisting the pairs the magnetic field is interupted and therefore canceling the noise.
265030
I couldn't tell you why a transmission Line has a ground wire attached, unless somebody thought it was a good place to put one. lol umm, details..?
201175
well if you have dialup and that's when you hear it then it would be your modem connecting to the internet through the phone line, and the noises would be the electrical signals being changed into sound and then being sent through the phone line
748193
I think the reason for the insulator layer is obvious. The conductor layer is probably to shield against emission of electromagnetic energy which can interfere with communications (such as radio and TV reception) and other electronic equipment, and may also be a safety measure to produce a high fault current to trip a breaker in the event of cable damage.
783905
its called "static electricity".???
266957
The PHYSICAL PHENOMENON here is called ELECTROSTATIC SHIELDING!\n\nIt says that electrostatic field inside a hollow metal conductor is ZERO! \nThe field will be zero even if the conductor encloses a charge!\n\nHere the CAR can be considered as the conductor,\nSo! even if there is  a million volts of lightning outside! You are safe inside!\nThanks- Hope I helped\nPeace!
841099
If you follow the instructions about how to unpack a package with anti-static instructions there is no risk, otherwise you might get an electric shock; hope not across the heart; it could be fatal even with a fraction of one amp.
279479
Check to see if your raido is plugged into the same receptacle as, say, a computer, or TV - the noise is most likely a 60Hz humm caused by a common ground with these types of equipment.  Also, shielded cable between the radio and the speaker would be helpful.