Why “junction” in BJT? Bipolar junction transistors are so named because their operation relies on current flow through two P–N junctions. Is this statement accurate?

Introduction / Context:
The term “bipolar junction transistor” encodes key physics: “bipolar” reflects participation of both electrons and holes as charge carriers, and “junction” points to the two semiconductor junctions that form the device’s core structure.

Given Data / Assumptions:

• Device families: NPN and PNP.
• Internal structure: emitter–base and base–collector P–N junctions.
• Forward-active operation with appropriate biasing of the two junctions.

Concept / Approach:
In forward-active mode, the emitter–base junction is forward biased to inject carriers, while the collector–base junction is reverse biased to sweep carriers into the collector. The presence and behavior of these two P–N junctions define current control and amplification mechanisms. Hence, the name “junction transistor” directly references the physical junctions involved.

Step-by-Step Solution:

Verification / Alternative check:
Energy-band and diode-equivalent models both depict two P–N junctions. Device IV curves corroborate diode-like behavior of each junction under bias.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing BJTs with MOSFETs, which use insulated gates rather than junction conduction for control.

Final Answer:
Correct