Chapter 24, Problem 81GP

A multilayer film capacitor has a maximum voltage rating of 100 V and a capacitance of 1.0 μF. It is made from alternating sheets of metal foil connected together, separated by films of polyester dielectric. The sheets are 12.0 mm by 14.0 mm and the total thickness of the capacitor is 6.0 mm (not counting the thickness of the insulator on the outside). The metal foil is actually a very thin layer of metal deposited directly on the dielectric, so most of the thickness of the capacitor is due to the dielectric. The dielectric strength of the polyester is about 30 × 10⁶ V/m. Estimate the dielectric constant of the polyester material in the capacitor.