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Difficulty: EasyTransistors

In an electronics schematic, a bipolar junction transistor (BJT) symbol features an arrow on the emitter lead pointing outward, away from the base. Which type of transistor is represented by this symbol?

  1. A
    PNP transistor
  2. NPN transistorAnswer
  3. C
    Junction field-effect transistor (JFET)
  4. D
    Zener diode

Answer

An NPN transistor is represented by a BJT schematic symbol where the emitter arrow points outward, away from the base.
In electronics schematic diagrams, the arrow on the emitter terminal indicates the direction of conventional current flow. For an NPN transistor, this arrow points outward (away from the base). A common memory aid is 'NPN = Not Pointing iN'.

Step-by-Step Solution

1
Identify the component family and terminal structure.
The component is a Bipolar Junction Transistor (BJT) with three terminals: Collector, Base, and Emitter.
Recognizing the core three-terminal configuration establishes the category of semiconductor device.
2
Analyze the direction of the arrow located on the emitter terminal.
The arrow points outward (away from the base terminal).
In standard schematic conventions, the arrow on the emitter indicates the direction of conventional current flow during forward bias.
3
Match the arrow direction to the correct transistor polarity type.
An outward-pointing arrow corresponds to an NPN transistor ('Not Pointing iN'), whereas an inward-pointing arrow corresponds to a PNP transistor ('Pointing iN Proudly').
Differentiating between NPN and PNP configurations is essential for determining circuit polarity and proper biasing.

Key Concept

BJT schematic symbols use an arrow on the emitter terminal to distinguish between NPN (arrow pointing out) and PNP (arrow pointing in) configurations.
Estimated Time:45s
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Topics

Transistors

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