Circuits and Networks - Dec 2014

Electronics and Comm. Engg. (Semester 3)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) Define Charge, Current, Potential difference, Lumped parameter, Time invariant, Branch and Tree.(7 marks) 1 (b) Calculate the node voltages for all the nodes shown in figure: 1 using nodal analysis. (7 marks) 2 (a) State and explain the Maximum Power Transfer Theorem. Drive the condition for maximum power transfer to the load for DC and AC circuit.(7 marks)

Answer any one question from Q2 (b) & Q2 (c)

2 (b) Draw the dual network shown in figure : 2. (7 marks) 2 (c) Explain the dot convention rule for the magnetically coupled Network shown in figure: 3. Also formulates KVL equations. (7 marks)

Answer any two question from Q3 (a), (b) & Q3 (c), (d)

3 (a) For the circuit shown in figure: 4 find the voltages and currents for all circuit elements using mesh analysis. (7 marks) 3 (b) State and explain (1) Norton's theorem (2) Milllman's theorem.(7 marks) 3 (c) Find current in 20 ohm resistance in the circuit shown in figure: 5 using superposition theorem. (7 marks) 3 (d) State Thevenin's theorem. Calculate current passing through 60Ω resistance in the circuit shown in figure: 6, using thevenin's theorem. (7 marks)

Answer any two question from Q4 (a), (b) & Q4 (c), (b)

4 (a) In the circuit shown in figure: 7, the switch "K" is closed at t=0. Assuming no initial current through inductor. Find current at t = 0.3 sec. Also find instant of time at which voltage across R equals voltage across L. (7 marks) 4 (b) Find laplace transform of f₁(t)=sin ωt f₂(t)=e^-at cos ωt.(7 marks) 4 (c) In a circuit shown in figure: 8, the switch has been at position A for a long time and is moved to position B at t = 0. Obtain current i(t) at t > 0. (7 marks) 4 (d) Explain the concept of Poles and zeros and their significance.(7 marks)

Answer any two question from Q5(a), (b) & Q5 (c), (d)

5 (a) Find h-parameters of the circuit shown in figure (7 marks) 5 (b) Derive expression of ABCD parameters in terms of Z and Y parameters.(7 marks) 5 (c) Derive relationship between incidence matrix (A), fundamental cut-set matrix (Q_f) and fundamental tie-set matrix (B_f).(7 marks) 5 (d) For the network shown in figure: 10 draw the oriented graph and Obtain (1) the incidence matrix (2) tieset matrix and (3) f-cutset matrix. (7 marks)