What is the electrical symbol for an NPN transistor represented by?

The electrical symbol for an NPN transistor is represented by a specific configuration of lines that indicates the collector, emitter, and base. In this symbol, there are typically three terminals labeled: the collector (C), the emitter (E), and the base (B).

For an NPN transistor, the arrow on the emitter points outward, indicating the direction of conventional current flow when the transistor is in its active mode. This symbol clearly delineates the roles of each terminal, providing essential information for circuit design and analysis. The configuration allows for easy identification and understanding of the transistor's function within a circuit.

In contrast, the other options do not accurately represent the components and connections necessary to convey the behavior of an NPN transistor. A vertical line or a series of horizontal lines lacks the essential details needed to distinguish an NPN transistor from other components. Similarly, a simple triangle does not convey the requisite complexity of this semiconductor device.