We solve the problem of a spherical capacitor with (almost) arbitrary permittivity of the dielectric.

Coupled RLC circuits are solved as coupled harmonic oscillators. The detuning of the circuits is calculated.

The classic problem of the resistance cube is solved. In addition, variations are outlined such as the C- and RLC-Cube

The serial RLC circuit is solved for dissipation and eigenfrequencies.

The capacitance of a coaxial capacitor with two embedded dielectrics is calculated.