Given that
distance between the two charges d = 0.16m
k =8.99 x 109 N/C
The electric field midway between two equal but opposite point
charges is E tot= 567 N/C
-----------------------------------------------------------------
The net electric feild midway between the two charges is
          Â
Etot = 2E
           Â
E = Etot/2
                =
(567 N/C)/2
              Â
= 283.5 N/C
The electricfield due to charge q is
            Â
E =kq/r2
Here r = d/2 = 0.08m
      So the magnitude of the
charge is
           Â
q = Er2/k
              Â
= (283.5 N/C)(0.08 m)2/(8.99 x109 )
              Â
= 2.018x10-10 CÂ Â Â Â Â Â
