96. The capacity of a spherical capacitor consisting of two concentric spheres with radii R1 = 50.0 mm and R2 = 100 mm (the space between the spheres is filled with oil (ε = 7.00)), C = 55.5 pF. What radius should a ball placed in oil have to have the same electrical capacitance as a spherical capacitor?

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