Question

According to Millers Theorem, what is the impedance in output port if I1 = 20 mA, I2 = 30 mA and Z = 2.3 kΩ?

(a) 0.38 kΩ

(b) 3.83 kΩ

(c) 0.57 kΩ

(d) 5.75 kΩ

The question was posed to me in semester exam.

I'm obligated to ask this question of Frequency Response in division Frequency Response of Electronic Devices & Circuits

Answer 1

Correct answer is (b) 3.83 kΩ

Easy explanation: To calculate theimpedance in output port, given I1 = 20 mA, I2 = 30 mA and Z = 2.3 kΩ:

Zin2 = (1 + α) × Z / α

α = I2 / I1 = 1.5

Zin2 = (1 + α) × Z / α = (1 + 1.5) × 2.3 / 1.5 = 3.83 kΩ