# Electric potential anyone help

1. Mar 1, 2009

### ahmedhassan72

Please anyone explain that to me as i cannot get it .How to link the potential difference which comes by integration dv=-E.dr like the potential inside and outside a charged sphere and the potential which comes by V=IR in our daily circuits how that comes i know that these are basics but i still want to understand and thanks in advance

2. Mar 1, 2009

### tiny-tim

Hi ahmedhassan72!

there are often two ways of defining electric units

voltage = energy/charge = work/charge = force"dot"distance/charge = (from the Lorentz force) electric field"dot"distance, or dV = E.dr

but also voltage = energy/charge = (energy/time)/(charge/time) = power/current, or V = W/I

3. Mar 2, 2009

### ahmedhassan72

so how can i apply the dv=-E.dr in circuit to measure a potential accross a resistor or capacitor to get to the v=IR ...also what is the lorents force....i got from u that if i have a stright line cylinderical wire and a battery then i can i measure by dv=-E.dr but for easiness i get it by v=IR