Question

The transconductance of a B.J.T.is 5mS (gm) while a 2KΩ (Rl) load resistance is connected to the C.E. stage. Neglecting the Early effect, what is the Miller multiplication factor for the input side?

(a) 21

(b) 11

(c) 20

(d) 0

I had been asked this question during an interview.

My question comes from Effect of Various Capacitors on Frequency Response topic in section Transistor Frequency Response of Analog Circuits

Answer 1

The correct answer is (b) 11

For explanation I would say: The Miller multiplication factor for the input side of a C.E. stage is (1+Av). Now, Av is the small signal low frequency gain of the C.E. stage which is gm*RL=10. Hence, the Miller multiplication factor is 11.