What does the symbol for a lightbulb look like in TPC schematics?

The symbol for a lightbulb in TPC schematics typically depicts a circle that contains markings representing the filament or a similar internal structure. This design effectively communicates the key characteristics of a lightbulb, illustrating how the component functions and allowing for universal recognition by those familiar with electrical schematics.

The circle itself symbolizes the glass enclosure of the bulb, while the filament markings signify the actual light-producing element within. This representation aligns with standard conventions used in electrical diagrams, ensuring clarity and ease of understanding for anyone interpreting the schematic.

The other options present symbols that do not accurately convey the specific design and function of a lightbulb as recognized in TPC schematics. For example, a square with a bulb outline does not communicate the details of the filament, and a triangle or diamond shape does not represent the traditional look of a lightbulb, which could lead to confusion in identifying components on a schematic.