The word “field” signifies how some distributed quantity (which
could be a scalar or a vector) varies with position The effect of the charge
has been incorporated in the existence of the electric field We obtain the
force F exerted by a charge Q on a charge q, as
F
r
=
41
0
2
πε
rQq
ˆ
(1 7)
Note that the charge q also exerts an equal and opposite force on the
charge Q