1. A parallel plate capacitor has a charge of 0.020 pC on each plate with a potenctial difference of 240 V. the parallel plates are separated by 0.40 mm of air. What energy is stored in this capacitor?
2. A parallel plate capacitor has a capacitance of 1.20 nF. There is a charge of 0.80 pC on each plate. How much work must be done by an external agent to double the plate separation while keeping the charge constant?