The electrostatic field of a point charge close to a grounded metallic sphere is derived.

The electrostatic potential of a dielectric sphere subject to an external field is calculated.

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

The potential of a finite line charge is calculated. Approximations are performed and shown to correspond to known results.

In a limiting procedure, the field of a dipole is calculated. Taylor expansion of 1/r is used.

The electric field of two charges with opposite charge is calculated.

A point charge in front of two grounded metallic half-planes, problem and solution.

Two dielectrics are separated by a plane interface, one contains a charge.

The movement of a dipole-like molecule in a constant electric field is derived using the Euler-Lagrange equations.

The field of a charge inside a metallic shell cavity is calculated. Screening is discussed.