2.5 Electric potential Let a charge q be in a given electric field e. we want to move Q by a displacement dl. then the work required against the electric force qe is dW=-QE dI Remember:QE is the external force If the path is closed the total work done is ∮qE:dl First consider the field e generated by a point charge Q, e Qr1/4 Eor, the en w oO r]. dI