Network Theory 2018 Question Paper — Government College of Engineerin…

The 2018 Network Theory previous year question paper (Government College of Engineering and Technology, Jammu), with every question and its marks.

Instructions

Attempt any Five Questions in all selecting at least two questions from each section.
All questions carry equal marks. (5x20=100)

Q1. Use differential equation approach to find transient response of series RL circuit subjected to DC excitation. Find the expressions of charging and discharging currents. [20 marks]
Q2. a) In the circuit shown the steady state exists when switch is at position 1. At t=0, the switch is moved to position 2. Find the current i(t) by using Laplace Transformation. b) Using Laplace Transform, find current i(t) for the network shown, when switch is closed at t=0. Assume initial charge on capacitor as $100\mu\text{C}$. [20 marks]
Q3. a) Define unit step, unit ramp and unit impulse functions with necessary mathematical and graphical representations. How these functions are related to each other? Explain. (11) b) Find Laplace Transform of the following functions: i) $f(t) = 5u(t-3) + 5t^2$ ii) $f(t) = 5[t\,u(t) + 6\delta(t-2)]$ iii) $f(t) = 6[t\,\delta(t-4) + 5\,u(t+2)]$ (3, 3, 3) [20 marks]
Q4. a) Explain dot conventions for magnetically coupled circuits. (8) b) Find f(t), when F(S) is given by $F(S) = \frac{5s^2 + 2s - 1}{s(s^2 + 2s + 5)}$ (12) [20 marks]

Q5. a) What are the restrictions of poles and zeros for a function to be a network function and a transfer function. (10) b) Find f(t) for the following function from its pole zero plot. $F(S) = \frac{(s+1)(s+3)}{s(s+2)(s+4)}$ (10) [20 marks]
Q6. Find Z-parameters and ABCD parameters for the following 2-port network. [20 marks]
Q7. a) How m-derived filters are different than constant k-type filters? Explain analysis of m-derived filters. (10) b) Design T and $\Pi$ sections of m-derived high pass filter having cut off frequency of 7 kHz and design impedance of 600 ohms. The frequency of infinite attenuation is 10.5 kHz. (10) [20 marks]
Q8. Explain a) Hurwitz Polynomial b) Cauer Synthesis of RL functions c) Foster Synthesis of RC functions. (6, 7, 7) [20 marks]