(ii) Note that the electric field E due to Q, though defined operationally in
terms of some test charge q, is independent of q This is because
F is proportional to q, so the ratio F/q does not depend on q The
force F on the charge q due to the charge Q depends on the particular
location of charge q which may take any value in the space around
the charge Q Thus, the electric field E due to Q is also dependent on
the space coordinate r