Question

Which one of the following statements is not correct of for a junction transistor?

• A. The base region is very thin.
• B. Emitter is more heavily doped as compared to collector.
• C. Emitter and collector can be interchanged.
• D. The surface area of collector is quite large as compared to emitter.

Answer 1

The correct option is C Emitter and collector can be interchanged.

In a junction transistor, the base is very thin and very lightly doped. The roll of emitter is to emit the majority charge carriers and hence the emitter is much more heavily doped compared to collector which is moderately doped. The collector collects the majority charge carriers, thus it requires large surface area compared to emitter. As the emitter and the collector each performs the specific task, thus they cannot be interchanged.

Hence the statements of option A, B and D are true.