Question

For the circuit given below, the value of z22 parameter is ____________ (a) z22 = 1.775 + j5.739 Ω (b) z22 = 1.775 – j4.26 Ω (c) z22 = -1.775 – j5.739 Ω (d) z22 = 1.775 + j4.26 Ω I got this question at a job interview. Origin of the question is Advanced Problems on Two Port Network in division 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

The correct choice is (c) z22 = -1.775 – j5.739 Ω Easiest explanation: z1 = \frac{12(j10)}{12+j10-j5} = \frac{j120}{12+j5} z2 = \frac{j60}{12+j5} z3 = \frac{50}{12+j5} z12 = z21 = z2 = \frac{(-j60)(12-j5)}{144+25} = -1.775 – j4.26 z11 = z1 + z12 = \frac{(j120)(12-j5)}{144+25} + z12 = 1.775 + j4.26 z22 = z3 + z21 = \frac{(50)(12-j5)}{144+25} + z21 = 1.7758 – j5.739 ∴ [z] = [1.775 + j4.26; -1.775 – j4.26; -1.775 – j4.26; 1.775 – j5.739] Ω.