SRM University 2007 B.Tech Electronics and Communications Engineering BANK : TRANSMSSION LINES AND WAVES GUIDES - Question Paper

4. discuss Reflection and derive the formula for reflection factor and reflection loss.
5. discuss about various kinds of distortion and derive the condition for distortionless
line.
6. a) Derive the formula of Input Impedance and Transfer Impedance of a Line.
b) The Primary Constants of a cable are R=80 ohms/Km, L= 2mH, G= 0.3
micro mhos/Km and C= 0.07 micro Farad/Km. compute the Secondary Constants
at 100Hz.
7. In a Line per kilometer R=42.9 ohms, L=0.07 mH, C=0.01 micro Farad and G=2.5
micro mhos. obtain the Attenuation Constant , Characteristic Impedance and the
phase velocity when w=5000 rad/sec.
8. A long transmission line of characteristic Impedance 500/_-43 ohms and
Propagation Constant of 0.07+j0.08 per Km is properly terminated. A voltage of
5V is applied at the sending end. compute the voltage and current at a distance of
10 km from the receiving end.
9. A transmission line has the subsequent parameters.
R=10.15 ohms/Km, L= 3.93mH/Km, C=0.00797 micro F/Km and G=0.29micro
mho/km. The Line is to be loaded to improve its performance at ?=5000 rad/sec.It
is to be loaded with loading coils of 0.246H and 7.3 ohms resistance at the
intervals of 7.88 km. Assuming that this loading is distributed compute
Zo,a,ß,?(velocity) and ? for the loaded line.
10. A 50 mile line has the subsequent measurements .
Zoc=200/_-42 ohms, Zsc=1890/_22 ohms.
obtain the value of Zo, a,ß,?(velocity) for this line if the frequency is 1200 Hz.
11. A Transmission line has a characteristics impedance 672/_-12 ohms and phase function .0355 rad/km, attenuation function 0.00755 neper/km. sending end voltage is 10 V at 1000Hz and the line is terminated by a 300ohms resistor. compute sending end current, receiving end current and voltage, efficiency of transmission.

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. describe Nodes and Anti Nodes.
7. Draw the Standing Wave trend for a line which is terminated with a load not equal

Earning:   Approval pending.