Voltage difference = Infinity?

[lluke9]

Voltage difference = Infinity?

So if there was a Q Coulomb point charge and a -Q Coulomb point charge with X meters of separation, and I wanted to find the voltage difference between those two charges...
How would I do it?Since V = kq/r + kq/r in this case, wouldn't I have to divide by 0?

V = Qk/X + -Qk/0

Or to avoid the problem, I just made it REALLY close to the charge, like:

V = Qk/X + -Qk/.0000001

Then I'd get some obscenely large number for the voltage for BOTH sides... But I know I'm missing something pretty major here. The potential difference shouldn't be that huge. The reason I want to know is because I'd like to know how to calculate a battery's voltage by knowing just the charges without using capacitor equations.
But I really can't figure this one thing out...

 

[Drakkith]

I'm not sure you are using the right equations. First, a battery isn't a capacitor, so why would you use the capacitor equations? The two are very different.

Second, I really don't know the math, so if I'm mistaken I apologize, but googling V = kq/r + kq/r gives me stuff on charged spheres, not point charges. (Edit: Further googling says I'm probably wrong, so just ignore this if it's true)

 

[lluke9]

I'm not sure you are using the right equations. First, a battery isn't a capacitor, so why would you use the capacitor equations? The two are very different.

Second, I really don't know the math, so if I'm mistaken I apologize, but googling V = kq/r + kq/r gives me stuff on charged spheres, not point charges. (Edit: Further googling says I'm probably wrong, so just ignore this if it's true)

Oh, I assumed a battery was like a capacitor in that it was just two terminals with opposite charges, like capacitor plates. Okay then, scrap that.But yeah, V = kq/r is applicable to point charges.
I wanted to stay away from charged spheres for simplicity's sake.

 

[Drakkith]

Oh, I assumed a battery was like a capacitor in that it was just two terminals with opposite charges, like capacitor plates. Okay then, scrap that.


But yeah, V = kq/r is applicable to point charges.
I wanted to stay away from charged spheres for simplicity's sake.

Nope, a battery generates its voltage from chemical reactions. http://en.wikipedia.org/wiki/Electrochemical_cell

 

[sardar]

I can confirm that voltage difference cannot be infinity. This is because infinity is not a real number and cannot be used in mathematical calculations. In this case, dividing by 0 is undefined and cannot be used to determine voltage difference.

To calculate voltage difference, we use the equation V = kq/r, where k is the Coulomb's constant, q is the charge, and r is the distance between the two charges. In your example, as the distance between the two charges approaches 0, the voltage difference will approach infinity. However, this is just a mathematical concept and does not reflect the actual physical value of voltage difference.

In practical terms, the voltage difference between two charges is limited by the material properties of the conductors and the electric field strength. As the distance between the two charges decreases, the electric field strength increases, but it is limited by the properties of the material. This means that the voltage difference cannot be infinite and will eventually reach a maximum value.

In terms of calculating a battery's voltage, it is important to consider the internal resistance of the battery and the material properties of the electrodes. These factors will affect the actual voltage output of the battery and cannot be determined solely by the charges present.

In summary, voltage difference cannot be infinity and it is important to consider the material properties and limitations in practical calculations.