Electromagnetics -- parallel plate capacitor energy storage 1. The problem statement, all variables and given/known data A parallel-plate capacitor 0.5m by 1.0m has a separation distance of 2cm and a voltage difference of 10V. Find the stored energy, assuming that ε=εo. If a 200-volt potential is applied in the capacitor, (a) determine the energy stored; (b) hold d1 at 2cm and the voltage difference at 200V, while increasing d2 to 2.2cm, determine the final stored energy. 2. Relevant equations U=(1/2)(CV2) C=εS/d 3. The attempt at a solution (a) C=((8.854x10-12)(0.5x1.0))/(0.02) C=2.2135x10-10 F U=(1/2)(2.2135x10-10)((10+200)2) U=4.8808x10-6 J (b) C=((8.854x10-12)(0.5x1.0))/(0.022) C=2.0123x10-10 F U=(1/2)(2.0123x10-10)((10+200)2) U=4.4371x10-6 J I'm not sure what to do with the voltage difference of the capacitor, so I added it with the voltage potential applied.