what exactly constitutes an electrical ground?
370125
you are almost right, electrical ground is allways relative to a higer potential source like a live wire and the current flows toward ground from the higer source, when you ar isolated (you have rubber shoes, you have a high resistance in the way of the current), there still a current flow, but it is so small (nano amperes) that you body cant feel it
383037
The fuse should always go on the hot (live) wire.   The neutral is the return path.  The ground is the safety ground in case a short develops and the hot wire comes in contact with the case of the appliance.    The neutral wire is supposed to be at ground potential, but because of resistive losses in the circuit (wires) this is not always the case.  This is why there is a safety ground, as it is not normally part of the electrical circuit.
456654
For the three contacts in a plug which are detailed below.\n\nLive\nThe live contact carries alternating current. The voltage varies by country, as set by national regulations and industry standards. In a few cases (older installations in Scandinavian countries, the outputs of British 110 V building site isolation transformers and probably a few other cases) both main conductors may be live, either being two phases from a three-phase system or being from a single-phase transformer with centre-tapped output. Some plug/socket combinations are designed in a way that a plug can be inserted only one possible way — this is referred to as a polarised plug (not to be confused with positive and negative polarity). Others allow the plug to be inserted with live and neutral either way round — this is referred to as an unpolarised plug. Furthermore even if live and neutral can only mate one way round it may be common to wire them without regard for which is which.\n\n\nNeutral\nThe neutral contact is in most (but not all) cases referenced to the earth. Except under fault conditions it generally does not pose a danger, but is nevertheless treated as live in most installation practices.\n\nThe main danger that can be posed by the neutral is it has a non-null voltage (possibly as high as the voltage on the mains line) after a broken neutral cable in the wiring. Neutral and earth (ground) are strongly related (see Ground (power)) and are usually connected at some point. However extra connections between the Neutral and the Ground must not be made unless the relevant jurisdiction's regulations allow it.\n\n\nEarth\nThe earth contact is only intended to carry current when connected to equipment that has developed an insulation fault (except for EMI/RFI filters which do cause a small current down the earth). If a bare live wire or live component in a device gets loose and touches the metal casing of the appliance, somebody touching the case may receive an electric shock. In many countries devices with metal cases must have the case connected to the ground connection. This reduces but does not eliminate the voltage present on the case relative to earth and metalwork connected to the earthing system.\n\nWhen the neutral is directly connected to the earth as part of the wiring system (a TN system) a fault to earth is a short circuit and therefore provided the wiring is done correctly the circuit breaker will open, or the fuse will blow. In the case of an indirect connection (via the body of the earth) between the earth and the neutral (a TT system) the resistance of the path is much higher and therefore a residual-current device (RCD) must normally be used to disconnect the fault.\n\nThe neutral core could in theory be used as a ground, but this would be dangerous if the core broke, so this is not normally used in building wiring or portable appliances. It is, however, used in some other situations with special precautions. For instance, in Switzerland, sockets in houses with the old two wire installation have the ground and neutral contacts connected together, probably supposing, that the professionally maintained house installation is much more reliable than plugged-in device. Also using the neutral as a ground prevents the use of RCDs.
512437
Ground or earth in a mains (AC power) electrical wiring system is a conductor that exists primarily to help protect against faults and which in normal operation does not carry current.\n\nThe term "ground" is used in Canada and the U.S.; the term "earth" is used in most of the rest of the English-speaking world. They are used synonymously here.\n\nNeutral is a circuit conductor that carries current in normal operation, and which is connected to earth.\n\n    * In a polyphase or three-wire AC system, the neutral conductor is intended to have similar voltages to each of the other circuit conductors, and similar phase spacing. By this definition, a circuit must have at least three wires for one to serve as a neutral.\n    * In the electrical trade, the conductor of a 2-wire circuit that is connected to the supply neutral point is also referred to as the "neutral". This is formally described in the US and Canadian electrical codes as the "identified" circuit conductor. If the entire system is only single phase then the current carrying conductor that is tied to earth is still a neutral by this definition.\n\nThe NEC and Canadian electrical code only define neutral as the first of these. In North American use, the second definition is used in less formal language but not in official specifications. In the UK the IEE definition is a conductor connected to the supply system neutral point, which includes both these uses.
571899
Lightening always takes the quickest path to ground. Water is conductive so if water is the closest conductive thing to ground from the point of origination then it well conduct electricity down to ground.
946508
I call it proper punishment.\nIf you touch something and get grounded, you probably shouldn't have touched it. Didn't momma teach you not to touch things that don't belong to you?\n\nYou're discharging a static electricity charge from your body to ground. \nAs you walk around your shoes build a static charge on your skin. If the humidity is low your body doesn't discharge the static as readily as it would if it were more humid.\nWhen you touch something metal your body is discharging the energy back to earth.
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.
111470
If the wire doesnt have a covering , the answer to your question is yes, electricity runs through and around the wire.
842699
Wood.  Wood is an insulator.  The other materials conduct electricity.
420266
Usually underground wires are surrounded by lots of insulation. Plus, the ground itself is an insulator. So even if it does get wet, the power won't go very far. Then there is the fact that a wire is just a wire. Wires do not really short out from water. It is the devices they connect that short out.
1137925
It is called static electric.
42364
Lighting is static electricity of charged particles in our atmosphere. The difference in the charges causes lightning. It is not often (If ever) for ground to cloud strikes over water. Water is a grounding source, since water is highly conductive (Salt water like oceans more so than fresh water like lakes and ponds.)and it is electrically, and physically grounded, the electrical energy is both grounded, and dissipated by the large volume of conduction.
1120246
Actually, electrical charges from the ground meet charges from the sky.  We  live in a magnetic field of 219v-dc.   Charges build up in clouds and are attracted to charge harbored within the earth.
16724
As you are building a computer, ESD sensitive parts can get damaged.  You can buy an ESD wrist strap and hook it to the AC outlets center screw (between the two plugs).  This will let the static electricity discharge through ground and not hurt your components.
46041
It's a short-circuit to ground to take the electrical charge through the rod's conductor and around, not through, adjacent structures which could be harmed by the passage of electricity.
26894
Basically nothing. Grounding is the standard term in North American and Earthing is the standard term in Europe and much of the rest of the world.
466747
touch a metal which is well grounded.