Hi guys,
I have been thinking about the physical meaning behind voltage and have come up with a few questions.
I think of voltage as being the amount of energy per coulomb of charge (J/C). Having a voltage across points A and B, say, means that the potential energy at point A is different (lets just say higher) than the potential energy at point B. I like to think of electric potential energy as being analogous to that of its gravitational counterpart; lifting up a mass up a distance gives it potential energy, lifting it higher gives it more potential energy etc.
If I have some charge, say 10C of +ve charge, and I grab a unit negative charge and hold it in place a certain distance from my positive bunch, we say that the negative charge has potential energy (since it WANTS to move towards the positive charges). If I provide a medium or a path for this negative charge to move (say a wire) to the less potential state (closer to the +ve charge) then this results in a current , which I like to think of as the number of charges that pass through a cross section of this wire to the other point B of lower potential.
So far so good? Please correct me if i'm wrong.
Now, my question is as follows:
How does a battery cell (galvanic cell) generate a point of higher potential A with respect to point B? My understanding is that the chemical reactions give rise to the "generation" of ELECTRONS (negative charge) but how does that cause one end to be of higher potential than the other? (ie: how does this link back to the explanation of voltage as being the fixing of a charge at a distance away from an opposing charge etc..? or the analogy to gravitational potential?)
I hope my question is clear.
Thanks guys
I have been thinking about the physical meaning behind voltage and have come up with a few questions.
I think of voltage as being the amount of energy per coulomb of charge (J/C). Having a voltage across points A and B, say, means that the potential energy at point A is different (lets just say higher) than the potential energy at point B. I like to think of electric potential energy as being analogous to that of its gravitational counterpart; lifting up a mass up a distance gives it potential energy, lifting it higher gives it more potential energy etc.
If I have some charge, say 10C of +ve charge, and I grab a unit negative charge and hold it in place a certain distance from my positive bunch, we say that the negative charge has potential energy (since it WANTS to move towards the positive charges). If I provide a medium or a path for this negative charge to move (say a wire) to the less potential state (closer to the +ve charge) then this results in a current , which I like to think of as the number of charges that pass through a cross section of this wire to the other point B of lower potential.
So far so good? Please correct me if i'm wrong.
Now, my question is as follows:
How does a battery cell (galvanic cell) generate a point of higher potential A with respect to point B? My understanding is that the chemical reactions give rise to the "generation" of ELECTRONS (negative charge) but how does that cause one end to be of higher potential than the other? (ie: how does this link back to the explanation of voltage as being the fixing of a charge at a distance away from an opposing charge etc..? or the analogy to gravitational potential?)
I hope my question is clear.
Thanks guys