Potential Of Negetive and Positive charges

[andyrk]

In a battery, why is the negative terminal at a lower potential than the positive terminal? And can we define absolute potential of a point? Potential means that the work done in bringing a charge from a given point to a given point on presence of the electric field created by another charge in whose vicinity the charge is moved. So if we can calculate the work done, we can easily calculate the potential can't we? So that means we can easily define absolute potential for any point?

 

[Dick]

In a battery, why is the negative terminal at a lower potential than the positive terminal? And can we define absolute potential of a point? Potential means that the work done in bringing a charge from a given point to a given point on presence of the electric field created by another charge in whose vicinity the charge is moved. So if we can calculate the work done, we can easily calculate the potential can't we? So that means we can easily define absolute potential for any point?

The negative terminal is at a lower potential because moving a positive charge from the positive terminal to the negative terminal does positive work. There's no such thing as an 'absolute potential'. Computing the work done only gives a relative potential difference. You have to define a reference potential at some position and then measure everything from that.

 

[rude man]

Room for one more?

Moving a positive charge from the negative to the positive terminal along a path outside the battery requires positive work. So the potential energy of a charge q in being moved externally from the - to the + post increases its potential energy by qV joules.