Ham Radio General Class Practice Test

Which symbol generally signifies an NPN junction transistor?

1. Symbol 1

2. Symbol 2

3. Symbol 7

4. Symbol 11

The correct answer is: Symbol 2

The correct answer is represented by the symbol that typically resembles an NPN junction transistor. In this symbol, you will find three terminals labeled as the emitter, base, and collector. The layout usually shows two arrows pointing outward from the junction, indicating the direction of current flow for an NPN transistor. In such a design, the arrow on the emitter points away from the base, signifying that current (conventional flow) leaves the emitter towards the outside circuit. This aligns with the characteristics of an NPN transistor, where electrons are the primary charge carriers flowing from the emitter to the collector. Understanding this symbol is essential for anyone working with electronic components since it conveys fundamental information about how the transistor functions within a circuit. The specific placement and direction of the arrows, along with the arrangement of the three terminals, are key elements that differentiate an NPN transistor from other types, such as PNP transistors, whose symbols reflect a different current flow direction.