What is the definition of voltage?

[rsrinivas]

Hi fiends
I have this question in my mind 4 a long time but not satidfied with the answer i got.
can anyone answer tis??

We say current as flow of electrons which is absolutely logical and understandable.
wat is voltage???
pls do not tell me that it is the amount of work done in bringing a upc from.....

 

[elmolla]

Re: Wat is this??

Voltage is a method used to quantify how much work we need to make the electrons move. Its just a method to measure how much work do we need if we want to move an electron between two places. i.e.

Lets follow the following conversation:
"- Some guy, * is some other guy"

-If we need to make these electrons move, what do we need to do?
*Apply some electric field.

-Why?
*To make a force to move the electrons

-How much electric field?
*This depends on the distance and the amount of electrons you need to move.

-Can we make this independent on the amount of electrons?
*Sure, but we can't get rid of the distance.

-OK. But can you quantify this in an equation
*Yeah sure. I'll do the force we need to move the electrons in terms of the electric field and then remove the charge dependence.

-OK.
*I've done the equations. But they are in terms of a quantity with the dimensions or Work per unit charge. (Force * distance / Charge)

-Cool.. Lets call it Voltage. But what is their physical significance?
*Well, its like if you want a ball to fall on the ground with a certain velocity, how high do you need to go before you leave it. i.e. How much potential energy do you need to give it so that when it reaches the ground it has a given kinetic energy?

-Well.. Voltage is just fine to describe this. I even like the name

 

[Shurik]

Re: Wat is this??

Voltage is what compel to flow electrons!
Electric potential !

 

[carlosftm]

Re: Wat is this??

Voltage is the difference of electrical potential between two points of an electrical network, expressed in volts. It is a measure of the capacity of an electric field to cause an electric current in an electrical conductor.

Information taken from:
https://en.wikipedia.org/wiki/Voltage

 

[amriths04]

Re: Wat is this??

i assume if anyone says that when a node is at a positive potential with respect to some other, then it acts as a source to that reference point.
the difference between the 2 quantities at those 2 points can be termed as voltage.
AMRITH.S.

Hi fiends
I have this question in my mind 4 a long time but not satidfied with the answer i got.
can anyone answer tis??

We say current as flow of electrons which is absolutely logical and understandable.
wat is voltage???
pls do not tell me that it is the amount of work done in bringing a upc from.....

 

[miGs]

Re: Wat is this??

In water analogy, voltage is the pressure that will make the water (current) to move from one point to another.

 

[engr_najam]

Wat is this??

we can consider an example of a stream of water coming down a mountin, now the quantity of water of water coming down is analogus to current, that is beacause of slope of the mountin analogus to voltage.
now as slope increased so the water speed will increase too resulting in hogh power,
same relation for voltage and current by ohm's law

 

[rsrinivas]

Wat is this??

Hi all
Thanks 4 ur reply's.
what is diference between potential and voltage.
is kinetic and potential energies linked to voltage?

 

[noghabi]

Wat is this??

voltage is potential difference between 2 points and potential of one point measured compared to a reference (Ground). (VAB=VA-VB)

 

[House_Cat]

Re: Wat is this??

Hi all
Thanks 4 ur reply's.
what is diference between potential and voltage.
is kinetic and potential energies linked to voltage?

Using chemicals or friction, we can put extra electrons on an object or we can take electrons away from an object (think of static charges or batteries). Unless we provide some means for electrons to move away from where we have put them, they have only potential energy - that is, they can do no real work. That potential energy is measured in units we call 'volts' - we measure the potential energy between where there are too many or too few electrons and other places the electrons might go if there was a way for them to get there.

Now, if we connect the object where we put extra electrons (or took some away) to another object - electrons will move to equalize across all the connected objects. We call the movement of electrons 'current' and use 'amps' as the unit of measurement. The moving electron charges display kinetic energy. (Moving objects have kinetic energy.)

By connecting two objects with different electron charges together we have converted the potential energy of the charge differences to the kinetic energy of charge movement. Volts have produced amps, or VOLTAGE EQUALS CURRENT times a circuit constant of proportionality. The circuit constant of proportionality is the circuit resistance to the electron flow. That observation by Georg Simon Ohm became what we call Ohm's Law (V=IR).

 

[neils_arm_strong]

Wat is this??

If we consider elementary charge to be +ve then this elementary charge always moves from high potential to low potential.The difference between these is the voltage.Correct me if i'm wrong

 

[House_Cat]

Re: Wat is this??

If we consider elementary charge to be +ve then this elementary charge always moves from high potential to low potential.The difference between these is the voltage.Correct me if i'm wrong

There are two "conventions" for charge movement in a circuit. There is no wrong or right about them, they are just two different ways of looking at current.

The first convention is electron flow. This convention says that electrons move from a region of high electron concentration to a region of lower electron concentration.

The second convention is hole flow, or positive current flow. This convention says that current flows from positive to negative, or from a region of less electrons (more positive charge) to a region with more electrons (more negative charge). This convention is the one most often taught in engineering courses.

Whether you regard either of the above to be from higher potential to lower potential depends on your point of reference. Which has higher potential - high electron density, or low electron denisty? The answer is either one, depending on how you define high or low - positive or negative.