Question

In an n-p-n transistor, the majority charge carriers in the emitter are

• A. holes
• B. electrons
• C. ions
• D. protons
• E. neutrons

Hint:

Just look at the name! For \textbf{n}-p-n, the outer sections are \textbf{n}-type (electrons). For \textbf{p}-n-p, the outer sections are \textbf{p}-type (holes). The emitter always shares the same "letter" as the collector.

Answer 1

The Correct Option is B

Concept:
Physics - Transistor Physics.
Step 1: Identify the transistor type.
The transistor is an n-p-n type. This means it consists of a p-type semiconductor layer sandwiched between two n-type semiconductor layers.
Step 2: Define the Emitter.
The emitter is the heavily doped section of the transistor designed to "emit" or supply the majority of charge carriers to the base.
Step 3: Determine majority carriers in n-type material.
In n-type semiconductors, the "n" stands for negative. The majority charge carriers are negatively charged electrons, while holes are the minority carriers.
Step 4: Conclusion.
Since the emitter in an n-p-n transistor is made of n-type material, its majority charge carriers are electrons.