A charge Q creates an electric field. A test charge q is used to measure the strength of the electric field at a distance d from Q. The electric field strength is defined as ?

E = F/q or E= kq/r^2

Explanation:

Electric field is defined as electric force per unit of charge.

E = F/q

also

E = kq/r^2

An electric field is created by electric charge, electric charges either repels or attracts other charges and exert force on other charges in the vicinity of the field.

From the above equation it can be seen that electric field is directly proportional to the amount of charge. Also it has an inverse relation with respect to electric field and distance of the charge.