UNIT II - TRANSMISSION LINE PARAMETERS
PART – A
1. What is group velocity?
2. What is patch loading?
3. What do you understand by loading of transmission lines?
4. Define Characteristic impedance?
5. What is frequency distortion?
6. Calculate the load reflection coefficient of open and short circuited lines?
7. Calculate the characteristic impedance for the following line parameters R = 10.4 ohms /km
L = 0.00367 H/km C = 0.00835μf /km G = 10.8x10-6 mhos /km
8. Define phase distortion?
9. Write the equation for the input impedance of a TL?
10. Define propagation constant?
11. Define wavelength?
12. Give the input impedance of a open and short circuit line?
13. Define reflection factor?
14. Define reflection loss?
15. What is meant by reflection co – efficient?
16. State the properties of infinite line?
17. Write the condition for a distortion less line?
18. When does reflection take place on a TL?
19. What is transfer impedance? State its expression?
20. What is difference between lumped and distributed parameters?
21. Draw the equivalent circuit of a TL?
22. Write the Campbell’s formula for propagation constant of a loaded line?
23. What is the need for loading?
24. A 50 ohm line is terminated in load ZR =90+j60 ohm. Determine the reflection coefficient.
25. How can distortion be reduced in a transmission line?
26. A transmission line has Z0= 745angle 12
and is terminated is = 100 ohm , Calculate the reflection loss in dB.
PART – B
1. Obtain the general solution of Transmission line, and Explain about physical significance of
TL? (16)
2. Explain about waveform distortion and distortion less line condition? (16)
3. Explain about reflection loss? (16)
4. Discuss in details about inductance loading of telephone cables and derive the
attenuation constant and phase constant and velocity of signal transmission
(v) for the uniformly loaded cable? (16)
5. Derive the equation of attenuation constant and phase constant of TL in terms of R,
L, C, G? (16)
6. Explain in details about the reflection on a line not terminated in its
characteristic impedance (z0)? (16)
7. Explain in following terms (16)
(i) Reflection factor (ii) Reflection loss
(iii) Return loss
8. Explain about telephone cable? (16)
9. (a) (i) Derive the expressions for the input impedance of a transmission line. 10) (ii) A cable
has the following parameters: R: 48.75 ohm/km, L: 1.09 mH/km, G: 38.75 MU/km and C: 0.059
uf/km. Determine the characteristic impedance, propagation constant and wavelength for a
source of f: 1600 Hz and Es: 1.0 volts. (6)
10 (i) A cable has been uniformly loaded by an inductance such that wl >> R . Assuming leakage
conductance to be nil, deduce an expression for attenuation and phase constant without
neglecting R. (ii) A transmission line has the following parameters per km R: 15 ohm, C: 15 uf,
L: 1 mH and G: 1 uU. Find the additional inductance to give distortion-less transmission.
Calculate attenuation and phase constant for the loaded line. ( 8 )
11. (a) Derive the equation of attenuation constant and phase constants of
transmission lines in terms of line constants R, L, C and G and
explain the significance of reflection coefficient and insertion loss.
12. A generator of 1V, 1 kHz supplies power to a 100 km open wire line
terminated in 200resistance. The line parameter are R = 10/km,
L = 3.8 mH/km, G = 1 × 10–6 mho/km, C = 0.0085 μ F / km . Calculate
the impedance, reflection coefficient, power and transmission
efficiency.
