Answer:
V = E * d voltage equals charge on plates * separation
F = E q force on charge q equals electric field * charge
W = F * d work done equals force times the distance moved
From the very first equation, the voltage depends on the distance between the plates - while the electric field remains constant
The potential difference will decrease as the separation of the plates increases because W remains constant - work done in moving test charge from one plate to another is constant - voltage is constant
