Electric potential

Electric potential:  

1. Electric work         Definition of voltage        WA,B  / q =  VA,B         Calculations for uniform field       V = E * d

2. Electric potential of a point charge           Two charges on a line          Potential of many point charges     Potential of a sphere

3. Reason one: U = q * V         Electrostatic potential energy        (Change of K) + (Change of U) = 0         | change of K | = | q * pd |

4. Reason two:    E = - (gradient of the V )             Visualization of scalar  field by equipotential lines         Equipotential lines are perpendicular to the field lines      E is always in the direction  of the decreasing potential                Equipotential lines for uniform field            Positive and negative equipotential lines for point charge       Equipotential lines for a physical dipole       

5. **Electric work is path independent      Electric potential and reference point      VA = VRef  - ( WRef , A   / q )    Theorem: voltage is equal to potential difference    VA,B = VA - VB      Potential is relative, voltage/pd is absolute