3. A flat air condenser with a plate area of 100 cm2 and a gap of 5 mm is charged up to a potential difference of 900 V. Without disconnecting from the voltage source, the plates are pushed apart to a distance of 1 cm between them. Determine the electric field strength, energy and volumetric energy density of the capacitor before and after the expansion of the plates.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)