A parallel-plate vacuum capacitor has 9.20 J of energy stored in it. The separation among the plates is 2.90 mm .If the separation is decreased to 1.55 mm.
a) What is the energy now stored if the capacitor was disconnected from the potential source before the separation of the plates was changed?
b) What is the energy now stored if the capacitor remained linked to the potential source while the separation of the plates was changed?