Suppose a parallel plate capacitor (with capacitance C1) is fully charged (to a value Qo) by a battery. The battery (which supplies a potential difference of Vo) is then disconnected. If the plates of the capacitor are then moved closer apart (the separation distance d between the plates is halved), describe quantitatively what happens to:
1) the capacitance of the capacitor
2) the potential difference between the plates
3) the charge on the plates
4) the energy stored in the capacitor