Question

Which of the following is unipolar transistor?

• A. p -n- p transistor
• B. n - p - n transistor
• C. Field effect transistor
• D. Point contact transistor

Answer 1

Answer: (C)

A field effect transistor (FET) is a three terminal semiconductor device in which the current is carried by majority carrier's only and is controlled by an electric field. A FET is a unipolar device since, the conduction of current is due to majority charge carriers only. While $p-n-p$ and $n-p-n$ are bipolar junction transistors, in which both holes and electrons play part in conduction process.