Final answer:
The electric field of a plane of charge is perpendicular to the plane and the field strength is constant with distance from it. This behavior is a unique property of an infinite plane of charge, in contrast to point charges where the field strength decreases with the square of the distance.
Step-by-step explanation:
The electric field of a plane of charge is described in Physics textbooks, including the ones that feature figures like 23.17 or similar. According to the information given, for a plane of charge, the electric field is perpendicular to the plane, and this is a common result found using Gauss's law for a sheet of charge. Regarding how the electric field strength changes with distance, for an infinite plane of charge, the field strength is constant with distance from the plane. This is a unique characteristic of an infinite plane of charge and distinguishes it from point charges where the electric field strength diminishes with the square of the distance.
In contrast, fields from two or more charges can interfere with each other, getting stronger where they add together and weaker where they cancel each other out. This complexity is noted in figures depicting electric fields from multiple charges, such as unlike charges or like charges, where field strength can vary significantly with distance and spatial configuration. For two unlike charges close together, the electric field is stronger in the region between them because the fields add together, while at large distances, the combined field mimics that of a single, weaker charge due to subtraction of the fields.