#) Electic Potential Energy:
+> Potential energy can be defined as the capacity for doing work which arises from position or configuration.
+> In the electrical case, a charge will exert a force on any other charge and potential energy arises from any collection of charges.
+> For example, if a positive charge Q is fixed at some point in space, any other positive charge which is brought close to it will experience a repulsive force and will therefore have potential energy.
+> The potential energy of a test charge q in the vicinity of this source charge will be: