SRM University 2007 B.Tech Electronics and Communications Engineering BANK FOR Transmission Lines and Wave Guides - Question Paper

9. A 50 mile line has the subsequent measurements . Zoc=200/_-42 ohms, Zsc=1890/_22 ohm obtain the value of Zo, a, ß, v(velocity) for this line if the frequency is 1200 Hz.

UNIT-II - TRANSMISSION LINES AT HIGH FREQUENCIES
PART-A
1. Write the assumptions that are made at high frequencies or at radio frequencies for a transmission line.
2. What is meant by a Zero dissipation line?
3. Write down the expressions for the characteristics impedance and propagation constant of a line at radio frequencies.
4. Write the voltage and current formula of a zero dissipation line .
5. What is meant by Standing Waves?
6. Define Nodes and Anti Nodes.
7. Draw the Standing Wave trend for a line which is terminated with a load not equal to Ro.
8. Draw the Standing Wave trend for a line which is terminated with i) open and ii) short circuit termination.
9. Define Standing Wave Ratio.
10. Write the Input Impedance formula for a dissipation less line.
11. Write the minimum & maximum value of Impedance of a zero dissipation line.
12. Write the Input Impedance formula for a zero dissipation line with i) open and ii) short circuit termination.
13. Draw the variation of Impedance of dissipation less line as a function of length for a line with Short circuit termination.
14. Draw the variation of Impedance of dissipation less line as a function of length for a line with Open circuit termination.
15. Write the Power formula for a dissipation less line.
16. If the load Impedance is 54-j74 ohms and Zo =150 ohms, obtain the Standing Wave Ratio.
17. A HF line has subsequent primary constants L=1.2mH/km, C=0.05microFarad/km and is operated at 1MHz. Determine Zo and ?.
18. A Lossless line having Zo = 50 ohms and terminated in a load ZR and VSWR on the line is. compute maximam and minimum values of impedance along the line.
19. Give the relation ranging from VSWR and Reflection Coefficient.
20. If the VSWR of a particular Transmission line is 2.5, then compute the magnitude of the reflection coefficient.

PART-B
1. a) discuss about Zero Dissipation Line and derive the equations for characteristic impedance, propagation constant and velocity of propagation.
b) Derive the expressions for voltage and Current at any point on a line at Radio Frequency terminated in ZR.
2. a) discuss about Standing Waves .Draw the Standing wave trend for i) Open circuit load, ii) Short Circuit Load and iii) Matched Load.

Earning:   Approval pending.