why?

Electric Feild

The space around an electric charge q in which another charge q_o experience force of attraction or repulsion is called electric feild of the charge q.

Intesity of Electric Feild

the Intesity of Electric Feild at a point in an electric feild is the ratio of the force acting on the test charge placed at that point to the magnitude of the test-charge

                               E = F/ q_o

_{where E and F are vector quantites}