Potential difference and EMF

1. May 25, 2012

tonyjk

hello... potential difference between two points in a circuit is the work done by the electric field to get a charge from point to another and for the emf it's also the work done but my question is for a potential difference the work is negative( the electrons lose energy) and for the emf the work done is positive( the electrons gain energy) ? or what? and the potential measured between a point of a circuit and the ground is it an emf or a potential difference( so it's like a given energy or a loss of energy)? thank you:D

2. May 25, 2012

tonyjk

i have read some threads made here but i didnt 100% get the response through them so please if any of the admins or members can help me.. thanks again

Last edited by a moderator: May 25, 2012
3. May 26, 2012

Yuri B.

Emf, voltage, electric charge, potential (difference), seems to refer to the more or less the same form of energy. They fade doing work if the energy is not renewed.

4. May 26, 2012

tonyjk

so the emf and potential difference are the same in a circuit? they have the same effects?

5. May 26, 2012

dlgoff

This is a good explanation. For further reading see. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/volcon.html#c1

6. May 26, 2012

tonyjk

okay i understand but my question is in a circuit when we measure a potential at a point A to the mass is it a potential difference or an EMF( if we take an EMF=5V and a resistance and after the resistance the potential is dropped and we have a new potential for exemple equal to 4.25V after the resistance,this potential refered to the mass is it an emf or a potential difference?)