## Solution: NAS MT-1 March 2020

NAS MT-1 March 2020

Semester IV, March 2020

Paper Code : ETEC 206, Paper : Network Analysis and Synthesis

Time : 1.5 Hours                                                                            MM: 30

Note: Attempt Q.No 1 which is compulsory and any two more questions from the remaining.

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Q1(a)   Check whether the given system is linear or not.                                 (2)

Y[n]     =          x[n+1] – x[n-1]

Q1(b)   Two ramp functions are given by f19t) = mtu(t) and f2 = m(t-a)u(t-a) where m1 and m2 are the slopes (+ve) and m1>m2. Draw final wave of these two functions

Q1(c)    ramp step u(t-5) is applied to a series RL network. Calculate the current i(t), assume R=1ohm and L=1H.

Q1(d) A switch S has been in contact with point 1 for long time, it is moved to position 2 at t=0. If at t=0+, the voltage across the inductor is 120 V. Find the value of the resistance R.

Q1(e) Find the value of F(0+), if ,

Q2(a) Determine the Laplace transform of the following periodic waveform.                         5

Q2(b) Find Vc(t) and IL(t) in the circuit below assuming zero initial condition.                                  5

Q3(a) Find i(t) following switching of K at t=0min the circuit below from A to B                               5

Q3(b) A resistance R and 5uF capacitor are connected in series across 100Vdc supply. Calculate the value of R such that the voltage across the capacitor below 50V in 5seconds after the circuit is switched on.    5

Q4(a) In the circuit shown below, steady state is reached with the switch in position “a”. At t=0, switching is done to “b” such that the circuit goes to discharging mode. Obtain the expression for the current i(t).               5

Q4(b) Assuming the initial current to be 2A through the inductor, find V0(t) in the figure below.      5