Question

A charge + q which is between the plates having A and B has a force of F of magnitude V is.

Answer 1

Electric Force:

F = qE
E = f/q

Electric Potential:

V= Ed

Substitution

V = Ed
   = F/q d

Answer 2

consider a capacitor with plates a and b who's a side is at Higher potential and B side at lower potential.
in a capacitor there is an electric field in directionn from positive plate to negative player.
E = F/q
where E is the electric field and Fis the force experienced by the particle.
F= Eq
And also E= V/d
F =Vq/d
here d is the speration b/w plates
the direction of this force is from positive plate to negative plate.