Final answer:
The question asks about fixed stations related to discrete connections on a filament transformer or precision resistors, which correspond to specific voltage, current, and resistance levels in electrical systems.
Step-by-step explanation:
The student's question pertains to fixed stations that allow the setting of specific electrical values, most likely in relation to a transformer or a circuit with resistors. The blank spaces in the question are intended to be filled with terms such as voltage, current, and resistance levels, which are fundamental concepts in physics, specifically within the study of electricity.
It mentions that these stations correspond to discrete connections on the filament transformer or to precision resistors, which implies a system where electrical parameters can be precisely controlled or set to predetermined values, often found in electrical engineering applications and physics experiments. These settings are critical in applications like transmission lines, resistance measurements, and various types of transformers, each playing a role in how electricity is distributed and utilized.