A parallel-plate capacitor with capacitance C, plate area A, and distance between the plates x, is connected to a battery until it is fully charged. The capacitor is now disconnected from the battery. Then the plates are pulled apart by an extra distance d. a) Briefly explain the state of the charge after the capacitor is disconnected from the battery. b) State whether the electric potential difference increases or decreases. Justify your answer based on the work done by an external agent.

A parallel-plate capacitor with capacitance C, plate area A, and distance between the plates x, is connected to a battery until it is fully charged. The capacitor is now disconnected from the battery. Then the plates are pulled apart by an extra distance d. a) Briefly explain the state of the charge after the capacitor is disconnected from the battery. b) State whether the electric potential difference increases or decreases. Justify your answer based on the work done by an external agent.