Question

If a two port network is passive, then we have, with the usual notation, the relationship as _________ (a) h21 = h12 (b) h12 = -h21 (c) h11 = h22 (d) h11 h22 – h12 h22 = 1 I have been asked this question in an international level competition. This intriguing question originated from Inverse Hybrid (g) Parameter topic in section Two-Port Networks of Network Theory Select the correct answer from above options network theory questions and answers, network theory questions pdf, network theory question bank, network theory gate questions and answers pdf, mcq on network theory pdf, gate network theory questions and solutions, network theory mcq Test , ies network theory questions, Network theory Questions for GATE EC Exam, Network Theory MCQ (Multiple Choice Questions)

Answer 1

Correct answer is (d) h11 h22 – h12 h22 = 1 For explanation: We know that, I1 = y11 V1 + y12 V2 ……… (1) I2 = y21 V1 + y22 V2 ………. (2) And, V1 = h11 I1 + h12 V2 ………. (3) I2 = h21 I1 + h22 V2 ……….. (4) Now, (3) and (4) can be rewritten as, I1 = \frac{V_1}{h_{11}} – \frac{h_{12} V_2}{h_{11}} ………. (5) And I2 = \frac{h_{21} V_1}{h_{11}} + \left(- \frac{h_{21} h_{12}}{h_{11}} + h_{22}\right) V_2 ………. (6) Therefore using the above 6 equations in representing the hybrid parameters in terms of the Y parameters and applying ∆Y=0, we get, h11 h22 – h12 h22 = 1 [hence proved].