Conservation of Electric Energy Practice Test

A $1.5,\text{V}$ ideal battery charges a capacitor $C=2.0,\mu\text{F}$, then is removed. Define the system as the capacitor only. The capacitor is then connected to an identical uncharged capacitor in parallel. Which statement correctly describes what happens to the electric potential energy stored in the capacitors?

A capacitor is charged to voltage $V_0$ and then disconnected from any battery. Define the system as capacitor + external agent. The agent slowly decreases the plate separation, increasing the capacitance by a factor of 3 while keeping charge on the plates constant. Which statement correctly describes the capacitor’s stored energy?