Work done by E field = increase in kinetic energy
Case 1: If positive charge move from high to low potential
Case 2: Negative charge move from low to high potential
Work done by external force = Work done on E field = decrease in kinetic energy
Case 1: If a positive charge move form low to high potential
Case 2: Negative charge move from high to low potential
If you confirm your deduction again, use g field.
Work done by gfield = increase in ke , mass falling from higher potential to a lower potential.
