This work is obviously proportional to q, since
the force at any point is qE, where E is the electric field at that
point due to the given charge configuration It is, therefore,
convenient to divide the work by the amount of charge q, so
that the resulting quantity is independent of q In other words,
work done per unit test charge is characteristic of the electric
field associated with the charge configuration This leads to
the idea of electrostatic potential V due to a given charge
configuration