what exactly is Voltage

[kap]

what exactly is voltage ?

more the charge in a point more the voltage?

In the pic I attached there are two posible paths for electrons to flow.
.path 1 through variable resistor 'R'.
.path 2 through voltmeter.
As I increse the resistance flow of electrons decrease in this path and volt meter shows Increased voltage.

so the voltage depends on that number of stationery charges ? if not, then on what ?
for example I took two plated and held them very need(capacitor, but i am not talking about capacitor here i want to understand voltage) and applyed a e.m.f source to both the plates, from one plate many electrons sucked and on the other plate ample electrons available, so in that way one plate is - charged and the other is + charged.


a) Current is a flow of free electrons, electrons have -charge, more the passing electrons more the current is and more the charge is.

b) e.m.f. is a external force which makes the elecrons move,generator and battry.


please correct my understanding if I am wrong on any of the points i mentioned above.



Thank you for your help friends.

 

[c131frdave]

No, not really. I'm not and electrical engineer, but I do run power plants for a living so I know a little bit.

The way it was first explained to me is to picture a water pipe. The water pressure in the pipe is voltage. Voltage is how hard the electricity is trying to get down the wire. (It's called potential also, for potential energy available). Resistance is like a valve in the pipe that only allows so much water through. The less resistance, the more water gets through. The flow itself is Amperage. The amount of flow depends on what is using the electricity.

An illustration, imagine a DC motor. Now imagine it as a water wheel. The higher the voltage, the faster the motor turns. The motor will have all sorts of issues with efficiency, so it only allows so many amps through it. It's called Amp draw. Like if a waterwheel had bad bearings. The higher the waterflow, the faster the wheel, but bad bearing will limit how much water it can take. A well lubricated wheel will draw lots of flow, which will deliver more power.

Amps X Volts = Watts. So, how much the wheel will take times how much water is pressing on the blades of the wheel equals how much power the wheel produces

I'm sure there will be plenty of engineers cringing at my explanation, but it is a basic picture to help understand electricity.

 

[kap]

thank you 'Dave', but i think you are talking about e.m.f, more the emf more the current flows. But I want to understand what exactly is voltage.

please read this again:
for example :
a) I took two plated and held them very need(capacitor, but i am not talking about capacitor here i want to understand voltage) and applyed e.m.f source to both the plates, from one plate many electrons sucked and on the other plate ample electrons available, so in that way one plate is - charged and the other is + charged.
b) Now I take the voltmeter reading, it shows 2v for an instance.
c) After that I push more electrons in a - charged plate, now it holdes more more number of electrons then before,
d)now if again I take the voltmeter reading, it will showe me increased voltage then before ? if yes then the voltage is depending on number or charges ? if not then what is true ?

 

[BobK]

Voltage is a measurement of how much energy is required to move a charge from point A to point B. This number can be negative, in which case energy is produced by the movement of charge.

In your capacitor example, the more charge you have on the two plates, the more energy will be required to move an electron from the + plate to the - plate, which is the same as the energy gained when moving an electron from the - plate to the + plate.

Bob

 

[kap]

thak you 'Bob',
you meen to say more the charges more the voltage is ?


But what factors produces the voltager, ?I mean what is the core source of voltage ? is that number of charges or emf ?

 

[c131frdave]

Respectfully, I think you are confused. Voltage is a measurement of the energy required to move electrons through a medium. Your examples used for your question have nothing to do with the definition of voltage.

 

[kap]

thank you "dave",

But I am talking about voltage source,not electronic component like motor or LED..

 

[c131frdave]

But the question was, "What is voltage".

You can't ask, "What is water", and then expect an explanation of what a Toyota is. Water is water. Voltage is Voltage.

I hope you find your answer though. Maybe a rephrasing would help.

 

[kap]

thank you 'dave',
No, please read my first post carefully if you want to.
but its ok,

I only want to understand what is voltage in deeper.
Is that the amount of charges or the e.m.f. which increases or decreases the voltage?

 

[alfa88]

Electricity is a form of energy as is heat. Voltage is the potential difference between no electrical energy and some electrical energy.
Practical sources would be batteries(chemical reaction) or generation( basically a magnet moving across a conductive wire . Search Michael Faraday.
Amperage is essentially the amount of Voltage per unit of time.

 

[BobK]

thak you 'Bob',
you meen to say more the charges more the voltage is ?


But what factors produces the voltager, ?I mean what is the core source of voltage ? is that number of charges or emf ?

No, charge is not always the source of voltage. In your example of a capacitor it is, but not always. Again, it is the amount of energy it takes to move a charge from point A to point B. Say there is a resistor with current flowing though it. The amount of work (energy) needed to get a unit of charge (Coulomb) across the resistor is a voltage. This is known as the voltage drops across a resistor. In this case, it has nothing to do with charge on one side vs the other side, it has to do with the amount of current flowing and the resistance (Ohm's law).

Bob

 

[kap]

thank you Bob,

OK, now Lets talk about capacitor analogy I exampled at the start of the post.

So the voltage accross depends on the number of charged particals "in case of capacitor"?

 

[kap]

thank you 'Alfa'

 

[fatman57]

Would it be correct to say that Voltage consists of a quantity of electrons and that this quantity is what determines the potential difference between two points?

Would it then be correct to say that Amps is the speed at which this quantity of electrons move?

 

[(*steve*)]

Would it be correct to say that Voltage consists of a quantity of electrons and that this quantity is what determines the potential difference between two points?

No

Would it then be correct to say that Amps is the speed at which this quantity of electrons move?

No.

 

[fatman57]

No



No.

Ok. Back to school for me I guess...

 

[(*steve*)]

So the voltage accross depends on the number of charged particals "in case of capacitor"?

No, it depends on the charge and the capacitance. The charge is measured in Coulombs.

An electron has a particular charge, but the total number of electrons in the capacitor does not change. One side may have more than the other though...

 

[kap]

i think more the electrons or + or - ions more the voltage is. again this is my understanding and i could be wrong.I need correction to my understanding.

 

[(*steve*)]

Ok. Back to school for me I guess...

Voltage is like potential energy.

An electron at the top if a hill has a higher voltage with respect to one at ground level than one half way up that hill.

Trying to define what that hill is requires some physics, but it's the "hill equivalent" for an electron in an electric field as potential energy is for an object in a gravitational field.

Current is the rate at which charge is moving. That is essentially the NUMBER of electrons as opposed to their actual speed. And it doesn't have to be electrons, but it usually is.

 

[(*steve*)]

i think more the electrons or + or - ions more the voltage is. again this is my understanding and i could be wrong.I need correction to my understanding.

No, voltage is a property of the potential energy of the electrons (actually a difference in potential energy).

The voltage won't change if you have 1, 10, a million, or several quintillion of them with the same energy.