# Question concerning Electric Field

1. Jul 12, 2006

### momomo_mo

I want to ask things about chapter "Electric Fields"
I am stucked in these words " Potential, Electric Fields, equipotential ..."

1.Why do we call potentail difference - Voltage?

2.Why do we call 2 objects have the same potentail if they are in contact with each other?

3.I am frustrated with the definition of potential -Work done per unit charge in bringing from infinity to the point r? How can it apply to the electrons in the circuit?

Thanks

2. Jul 12, 2006

### thiotimoline

Potential difference is analogous to the difference in terms of current. A difference means there is a flow, and is called voltage.

3. Jul 12, 2006

### Hootenanny

Staff Emeritus
Just further to what thiotimoline said;
Voltage was so named after the inventor of the voltaic pile (a rudimentary battery), A. Volta - I forget his first name. The volt is not a [SI] base unit but rather a derived unit. The base unit of potential difference is defined as the energy transferred per unit of charge, J.C-1. Equally, one volt can also be described as the potential difference when a current of one ampere dissipates one watt of power in a conductor and so can also have the base unit m2.kg.s-3.A-1.
Perhaps you can answer this one yourself, what creates a potential [difference]?
Quite simply in any circuit there is an electric static field which requires work to be done to move a charge, remember a definition of voltage - work done per unit charge?. Perhaps http://en.wikipedia.org/wiki/Electric_potential" [Broken]from wikipeda on electric potential would be helpful.

Last edited by a moderator: May 2, 2017