Question

A power transistor is a ____________

(a) three layer, three junction device

(b) three layer, two junction device

(c) two layer, one junction device

(d) four layer, three junction device

This question was addressed to me in quiz.

My query is from Power BJTs in division Differential and Multistage Amplifiers of Electronic Devices & Circuits

Answer 1

The correct choice is (b) three layer, two junction device

To explain I would say: A power BJT has three layers, p-n-p or n-p-n forming two junctions.

p-n-p: two positive (p) layers and one negative (n) layers in between them.

n-p-n:  two negative(n) layers and one positive(p) layers.