Question

calculate the voltage of a battery connected to a parallel plate capacitor with a plate ares of 3.0 cm² and a plate separation of 5mm if the charge stored on the plates is 6.0 pC

Answer 1

Find the capacitance:

$$C=\frac{\epsilon_0A}{d}.$$

Find voltage:

$$V=\frac QC=\frac{Qd}{\epsilon_0A}=\frac{(6·10^{-12})(0.005)}{(8.85·10^{-12})(3·10^{-6})}=1129\text{ V}.$$