Question

A 12.0- A 12.0- A 12.0-V battery remains connected to a parallel plate capacitor with a plate area of 0.204m^2 and a plate separation of 3.14mm .
What is the charge on the capacitor?
Q = C
How much energy is stored in the capacitor?
Uc = J

What is the electric field between its plates?

E = V/m

Answer 1

Calculate the capacitance (C = eo A/d)
then
Q = C V
and
energy = .5 Q V = .5 C V^2
then indeed
E = V/ spacing in meters between plates.