Electric Field 1

Electric field :- It is the area around any charge. When any charge enters in it then that charge feel force ( attraction or repulsion ).

Electric Field Intensity :- The force acting on a unit positive charge is known as electric field intensity.
It is denoted by 'E'.
E = F/q0
here q0 is unit positive charge.
or we can say force per unit charge is known as electric field intensity.
It's unit is newton per coulomb(N/c).

Electric field intensity due to a point charge :-
Let a positive charge +q is present at point 'o' and another charge +q0 present at 'p', r distance from o.

Due to same charge a repulsive force acting
F = kqq0/r^2
when this charge enters into electric field then electric field intensity on it
E = F/q0  ( according to the definition of electric field intensity)
so E = (kqq0/r^2)/q0
    E = kqq0/r^2q0
    E = kq/r^2
here k = 1/4πε0 = 9*10^9 Nm^2/c^2
so E = 1/4πε0(qq0/r^2)