A 1.9-pF parallel plate capacitor has a potential difference of 10.0 V across it. The plates are 1.1 mm apart, and the space between them contains air.
a) What is the charge on the capacitor?
b) How much energy is stored in the capacitor?
c) What is the area of the plates?
d) What would the capacitance of this capacitor be if the space between the plates were filled with polystyrene (? = 2.6)?