Question

In the circuit given below, RI = 1 MΩ, RO = 10 Ω, A = 10^6 and VI = 1μV. Then the output voltage, input impedance and output impedance respectively are _________

(a) 1 V, ∞ and 10 Ω

(b) 1 V, 0 and 10 Ω

(c) 1V, 0 and ∞

(d) 10 V, ∞ and 10 Ω

I have been asked this question during an internship interview.

I need to ask this question from Advanced Problems on Network Theory in section Network Theory and Complex Circuit Diagram of Network Theory

Answer 1

The correct answer is (a) 1 V, ∞ and 10 Ω

To explain: VO (output voltage) = AVI = 10^6 × 10^-6 = 1 V

V1 = Z11 I1 + Z12 I2

V2 = Z21 I1 + Z22 I2

Here, I1 = 0

Z11 = \(\frac{V_1}{I_1} = \frac{V_O}{0}\) = ∞

Z22 = \(\frac{V_2}{I_2} = \frac{AV_I}{I_2}\)

Or, Z22 = \(\frac{1}{I_2}\) = RO = 10 Ω.