Question

What is the approximate hybrid parameter voltage gain of a CB amplifier?

(a) hfe × RL / hie

(b) -hfe × RL / hie

(c) hfe × RL / hoe

(d) -hfe × RL / hoe

This question was posed to me during an interview.

Question is from Approximate Hybrid Model and its use in CE, CB, CC topic in division Small-Signal Low-Frequency AC models of Transistors of Electronic Devices & Circuits

Answer 1

Right option is (a) hfe × RL / hie

To elaborate: The voltage gain of a common base (CB) amplifier can be expressed in terms of approximate hybrid parameters. The voltage gain is equal to hfe × RL / hie where, RL is load resistance, hie is input resistance of CE amplifier and -hfe is the current gain of CE amplifier.