Table of Contents

Toggle**Important RGPV Question**

**EC-503(A), Communication Network & Transmission Lines**

**V Sem, EC**

## UNIT 1

**Q.1** Explain the design of asymmetrical attenuators. Also discuss their working principle. **( RGPV Nov 2023 )**

**Q.2** A symmetric T-section has impedance of j300Ω in each series arm and impedance of j80Ω in each shunt arm. Find characteristic impedance. **( RGPV Nov 2023 )**

**Q.3** Define parameters of a 2-port symmetrical network and derive mathematical expression for the same. **( RGPV Nov 2022 )**

**Q.4** A symmetrical 2-port T-network has elements (10+j2) ohms in the series arms, and (10+j5) ohms in the shunt arm. Find its characteristic impedance. **( RGPV Nov 2022 )**

**Q.5** Define parameters of a 2-port asymmetrical network and derive mathematical expression for image impedance.

**Q.6 **An asymmetrical 2-port T-network consists of Z_{1} = 2+j3 ohms, Z_{2} = 2+j10 ohms and Z_{3} = 30 ohms,, Where impedance 2, constitutes the shunt arm of the network. Calculate the image impedances for this network. **( RGPV Nov 2022 )**

**Q.7** What is Attenuator? Explain. And derive design equations for a 2-port T-attenuator.

**( RGPV Nov 2022 )**

**Q.8** Discuss double stub matching technique in brief. **( RGPV Nov 2022 )**

**Q.9** Asymmetric T-section has impedance of j300Ω in each series arm and impedance of j80Ω in each Shunt arm. Find characteristic impedance.** ( RGPV Dec 2020 )**

**Q.10** What is meant by insertion loss? Explain with diagram. **( RGPV Dec 2020 )**

**Q.11** What is matching network? Explain bridged T-network. **( RGPV Dec 2020 )**

**Q.12** Define the terms

i) Attenuation and phase equalizer

ii) Reflection co-efficient

**( RGPV Dec 2020 )**

**UNIT 2**

**Q.1** What is the function of m-derived section in a composite filter? **( RGPV Nov 2023 )**

**Q.2** Design a high pass filter and analyze the performance. ** ( RGPV Nov 2023 )**

**Q.3** What are m-derived filters? Explain. Describe their applications in brief.

**( RGPV Nov 2022 )**

**Q.4** A band pass filter has lower cut-off frequency f, and upper cut-off frequency f2. Find its resonance frequency. **( RGPV Nov 2022 )**

**Q.5** What are the limitations of constant-K. filters? Explain How these can be resolved? **( RGPV Nov 2022 )**

**Q.6** Design an m-derived filter (T-section) with the following specifications:

Cut-off frequency f 1000 Hz, frequency of infinite attenuation fin = 1250 Hz, Nominal resistance R = 50 ohms.

**( RGPV Nov 2022 )**

**Q.7** An asymmetrical 2-port T-network consists of Z_{1} = 10+j40 ohms, Z_{2} = 5+j2 ohms and Z_{3} = 20 ohms, Where Z_{3 }is the shunt arm element. Find image impedances for this network. **( RGPV Nov 2022 )**

**Q.8** Realize the nerwork function

F(s) ={(s^{2}+1)(s²+9)}/{(s²+4)(s²+16)}.

**( RGPV Nov 2022 )**

**Q.9** Discuss various kinds of filter design (approximation) techniques in brief. **( RGPV Nov 2022 )**

**Q.10** Give reactance curves for LPF and HPF filters (L-C). Indicate all bands and cut-off points clearly. **( RGPV Nov 2022 )**

**Q.11** Design a-m-derived filter. **( RGPV Dec 2020 )**

**Q.12** Explain Butter worth approximation for low pass filter. **( RGPV Dec 2020 )**

**Q.12** Explain Chebyshev approximation for high pass filter. **( RGPV Dec 2020 )**

**UNIT 3**

**Q.1** Write an operating principle of Bott Duffin method. Explain the concept of minimum positive real function. **( RGPV Nov 2023 )**

**Q.2** Discuss the Foster and Causer Network. Explain the Brune’s method and synthesis coefficient.

**( RGPV Nov 2023 )**

**Q.3** What are the necessary condition for a function to be realized? Explain. **( RGPV Nov 2022 )**

**Q.4** Consider a network function F(s) =((s+6)}/{(s+4)(s+8)} [{K_{1}/(s+4)}+{K_{2}/(s+8)}]. Find the values of constants K_{1} and K_{2} and realize this network function. **( RGPV Nov 2022 )**

**Q.5** Realize the network function F(s)= [{(s+2)(s+6)}/{(s+3)(s+9)}]. **( RGPV Nov 2022 )**

**Q.6** Describe the Cauer-I and Cauer-II forms of the networks with the suitable examples. **( RGPV Nov 2022 )**

**Q.7** Synthesize in cauer form s³+4s²+2s+1 / s^{3}+s^{2}+s **( RGPV Dec 2020 )**

**Q.8** Test whether the function is Hurwitz F(s)= s^{5}+s^{4}+2s^{3}+2s² + 2s+1 **( RGPV Dec 2020 )**

**Q.9** Realize the z(s)=- 3s²+s+6 / 2s^{3}+s^{2}+s+4 in foster- I form. **( RGPV Dec 2020 )**

**UNIT 4**

**Q.1** Derive expression for voltage and current at any point on the transmission line in terms of characteristic impedance and length.

**( RGPV Nov 2023 )**

**Q.2** Derive design equations for full series equalizers. **( RGPV Nov 2023 )**

**Q.3** What is matching network? Explain bridged T-network. **( RGPV Nov 2023 )**

**Q.4** A cable has an attenuation of 3.5 dB/km and a phase constant of 0.28 radians/km. If 3 volts are applied to the sending end, what will be the voltage at point 10 km down the line when the line is terminated in its characteristic impedance? **( RGPV Nov 2023 )**

**Q.5** Explain the reflection coefficient of different transmission lines. Explain briefly about open circuit and short circuit line. **( RGPV Nov 2023 )**

**Q.6** Discuss characteristics preparation co-efficient and Image transfer co-efficient. **( RGPV Nov 2023 )**

**Q.7** Describe characteristics of an infinite line and matched line. And discuss the phenomenon of power reflection on line in brief. **( RGPV Nov 2022 )**

**Q.8** The measurements taken on a line are as follows: Open circuit impedance Z-1600 ohms Short circuit impedance Z-400 ohms. Find its primary and secondary coefficients. **( RGPV Nov 2022 )**

**Q.9** What are the important properties and applications of a short circuited lines and open circuited lines? Explain in detail. **( RGPV Nov 2022 )**

**Q.10** Describe major applications of the Smith’s chart. **( RGPV Nov 2022 )**

**Q.11** What are the various kinds of distortions occurring on a line? Derive conditions for a line to be distortion less. **( RGPV Nov 2022 )**

**Q.12** A transmission line is characterised by R=8.2 ohms per km and G-15 micro-Mhos per km. Calculate it’s primary and secondary constant. **( RGPV Nov 2022 )**

**Q.13** Describe the characteristics of composite filters (L-C) in brief. **( RGPV Nov 2022 )**

**Q.14** Derive design equations for a low pass m-derived filter. **( RGPV Nov 2022 )**

**Q.15** Derive expression for voltage and current at any point on the transmission line in terms of characteristic impedance and length. **( RGPV Dec 2020 )**

**Q.16** Draw the lumped parameter equivalent of transmission line and explain briefly. **( RGPV Dec 2020 ) **

**UNIT 5**

**Q.1** A generator of IV, 1 kHz supplies power to a 100 km long line terminated in Z, and having the following constants, L=0.00367 H/km R = 10.4 Ω/km, G=0.8×10^{-6} mho/km, C=0.00835×10^{-6} F/km Calculate Zo, attenuation constant, phase constant, wavelength and velocity, received current, voltage and power.

**( RGPV Nov 2023 )**

**Q.2** Explain double stub impedance matching and its advantage over single stub.

**( RGPV Nov 2023 )**

**Q.3** Write a short note on any two:

i) Lattice and Bridged T networks

ii) Frequency transformation

iii) Conditions for real function

iv) Introduction to micro-strip lines

**( RGPV Nov 2023 )**

**Q.4** Describe characteristics of a quarter wave line. Find input impedance of a quarter wave line with characteristic impedance Z_{O} = 100 ohms and load resistance of R₁= 4 ohms. **( RGPV Nov 2022 )**

**Q.5** Derive transmission line equations. **( RGPV Nov 2022 )**

**Q.6** Define the terms namely reflection factor (constant) and VSWR. A line (with characteristic Impedance Z_{O} = 50 ohms) is terminated in Z_{L} = 100 ohms. Find reflection factor (constant) and VSWR for this 2-wire line. **( RGPV Nov 2022 )**

**Q.7 **Give description of line parameters in brief. **( RGPV Nov 2022 )**

**Q.8** Discuss the single stub matching technique in brief. **( RGPV Nov 2022 )**

**Q.9** Explain any one method of power measurement on the line. **( RGPV Dec 2020 )**

**Q.10** Explain double stub impedance matching and its advantage over single stub. **( RGPV Dec 2020 )**

**Q.11** Write short notes on the following-

a) Half wave line

b) Micro strip Line

c) Foster network

d) Distortion less line

**( RGPV Dec 2020 )**

**— Best of Luck for Exam —**