Mumbai University Previous year question papers
IV Sem ETC-Examination June 2008
Principles of Communication
N.S. : (1) Question NO.1 is compulsory.
(2) Attempt any four questions out of remaining six questions.
(3) Assume suitable data if required.
.Q.1 Answer the following. (Any Four)
(a) What is FM capture effect?
(b) Write a note on FDM.
(c) What is ISI? Discuss four primary causes of IS1.
(d) Explain Harmonic distortion and Intermodulation distortion.
(e) Compare different single sideband filters.
Q.2 (a) For an electronic device opetatingat a temperature of 17° C with a bandwidth of 10KHz, determine .
(a) Thermal noise power in watts and dBm.
(b) Rms noise voltage .fora 100 0 internal resistance and a 100 0 load resist~ce
(b) Draw and explain Delta modulation transmitter and receiver. What is slope’ overload distortion? .
Q.3 (a) Compare AM and FM in all respects.
(b) Explain ISB with neat block diagram.
Q4 (a) Draw a neat block diagram of Differential Pulse code modulation transmitter and receiver and explain the same.
(b) DefineFM and derive equation of FMwave.
Q.5 (a) Explaingenerationand demodulationof PAMsignal with the help of suitable diagrams.
(b) Explainthe working of ratio detectorwith the help of voltage versus frequencyresponse curve.
Q. 6(a) Draw the schematic diagram of simplified medium – power transistor AM DSBFC mbdtilator and explain t}1eoperation with the help of collector waveforms with no modulating signal and collector waveforms with a modulating signal.
(b) Draw the block diagram of TRF radio receiver and explain the same.
Q. 7(a) Explain indirect method of FM generation.
(b) One inptit to a conventional AM modulator is a 500 KHz carrier with amplitudeof 20 Vp.The second input is a 10KHz modulating signal that is of sufficient amplitude to cause a change in the output wave of ;1;7.5Vp. Determine
(a) Upper and lower sideband frequencies
(b) Modulation coefficient and percent modulation
(c) Peak amplitude of the modulated carrier and the upper and lower frequency voltages
(d) E~pression of the modulated wave. .