## Current and Potential Difference

 3.1 Current and Potential Difference

 Electric field The region around a charged particle where any electric charge in the region will experience an electric force

The patterns of observed electric fields for positive charge and negative charge are as follows:

 (a) The direction of the electric force line avoids the positive charge. (b) The direction of the electric force line to negative charge.

 Electric field strength, E Electric force acting on a unit positive charge placed at the point. $$E=\dfrac{F}{q}$$, where E = electric field strength, F = electric force, Q = quantity of electric charge $$E=\dfrac{V}{d}$$, where E = electric field strength, V = potential difference, d = distance between plates

 Electric current, $$I$$ Rate of flow of charge in a conductor $$I = \dfrac{Q}{t}$$, $$I$$ = current, Q = total charge, t = time

 Potential difference Work done in moving one coulomb of charge from one point to another. $$V = \dfrac{W}{Q}$$ or $$V=\dfrac{E}{Q}$$, where V= potential difference, W = work done,  E = energy transferred, Q = amount of charges flowing