Question

An $n-p-n$ transistor has three leads $A, B$ and $C$. Connecting $B$ and $C$ by moist fingers, $A$ to the positive lead of an ammeter, and $C$ to the negative lead of the ammeter, one finds large deflection. Then, $A, B$ and $C$ refer respectively to :

• A. Emitter, base and collector
• B. Base, emitter and collector
• C. Base, collector and emitter
• D. Collector, emitter and base.

Answer 1

Answer: (A)

Emitter, base and collector

Answer 2

We know that the transistor is a current operated device (Beta model) and that a large current ($I _{ c }$ ) flows freely through the device between the collector and the emitter terminals when the transistor is switched fully-ON.
Therefore. $A$ is emitter and $C$ is collector.