whats different about ground and short in electric circuits?

Answer 1

The "ground" is the point of lowest potential in a circuit. Just as all water runs downhill, all electricity runs eventually to the lowest potential. The "lowest potential" is the "ground," just like the point that all water flows downhill to could be called the "ground." Water is running toward the "ground;" electricity also flows toward the "ground."

As the electricity moves through things (like resistors), it loses some of its potential (just as water that moves to a different height). A "short circuit" is a very low resistance alternate path around an electrical component. For example, if electricity faces a resistor which is wired in parallel with a piece of wire, most of the electricity (in fact, nearly all) will travel through the wire instead of the resistor. If there is another resistor "downstream" of this parallel combination, then the electricity will reach it with a higher potential. That is, instead of dropping some of its energy across the first resistor, it will retain that energy since it traveled through the wire instead and thus the second resistor will face more potential.

If a portion of a circuit is "short circuited" to "ground," then that point in the circuit is brought to the lowest potential (this is done by placing a wire in parallel with a large section of circuit such that one end of the wire is placed on the "ground" of the circuit and the other end is placed in the middle of the circuit somewhere). In the water example, if the middle of its original path is "shorted to ground," it's much like reshaping the hill so that the water travels down a steeper incline and hits the "ground" right at that point.

If an entire circuit is "short circuited" (that is, a wire is placed from the highest potential to the lowest potential) then all of the energy of the circuit must be released through the very low resistance of the wire. (picture water running down a cliff rather than a hill; it has to drop to the "ground" immediately) Because the wire has such low resistance, this will mean that a great deal of current will be generated. This will draw so much power from the voltage source that the intrinsic resistances in the voltage source (as well as the low resistance in the wire) will start to heat up. This can damage the voltage source and the wire.

To keep going with the water analogy, imagine a water pump supplying a constant pressure to a water circuit. That pressure is much like a voltage. If the circuit uses very small diameter pipe and places objects (wheels, balls, and other things that can be moved around by wire) in the flow, it will be easy to maintain high pressure without much current. Water will quickly back-up as it stresses to get through the small pipe. However, if a large pipe is used instead (or simply no pipe) then the pump will run as fast as possible in order to try to keep the pressure up. It will most likely fail to be able to provide enough pressure (because the water faces so little resistance and so it doesn't "back up" to the pump) and the motor inside the pump will overheat and could be damaged.

Answer 2

Ground is a reference. It is normal (and needed) to have ground in all circuits. Electricity flows through a path. One side is the potential (or, positive) of the circuit and the other is the ground. A short is not a wanted element of electrical flow. It disrupts the normal path and sends the current into parts that were not intended. This can cause a shock to people, overheating of equipment (possibly resulting in fire), and/or other damage or even death.

Answer 3

I hope this helps:

A short circuit is a fault whereby electricity moves through a |circuit in an unintended path, potentially causing overheating, fire or explosion

In electrical engineering, the term ground or earth has the following meanings:

An electrical connection to earth. The part directly in contact with the earth (the earth electrode) can be as simple as a metal (usually copper) rod or stake driven into the earth, or a connection to buried metal water piping (though this carries the risk of the water pipe being later replaced with plastic). Or it can be a complex system of buried rods and wires. The resistance of the electrode-to-earth connection determines its quality, and is improved by increasing the surface area of the electrode in contact with the earth, increasing the depth to which it is driven, using several connected ground rods, increasing the moisture of the soil, improving the conductive mineral content of the soil, and increasing the land area covered by the ground system. This type of ground applies to radio antennas and to lightning protection systems.

Answer 4

you won't get shocked by an electrical wire if you don't touch the ground.