Mumbai University Previous year question papers Basic of Analog and Digital Communication System June 2010

Mumbai University Previous year question papers

IV Sem Electronics Examination June 2010

Basic of Analog & Digital Communication System

N.B.

Question NO.1 iscompulsory.

Attempt any four questions from remaining six questions.

Assume suitable data wherever necessary.

Figures to the right indicatefullmarks. – –

lIiustrateanswers with sketches wherever required-

1. Attempt any four of the following :-

(a) Classify and explain to various noises that affect communication.

(b) DSB-FC (A.M.) is wastage of power and bandwidth. Justify.

(c) Derive the expression for A.M. “–

(d) Explain the following characteristics of radio receiver :-

(i) Sensitivity

(ii) Selectivity

(iii) Fidelity

(iv) Double spotting

(v) Image frequency and itsrejection.

(e) Explain companding and itsneed in communication.

 

2. (a) Explain basic block diagram of communication in detail.

(b) Explain the following terms :-

(i) Signal to noise ratio

(ii) Noise factor

(Hi) Noise figure

(iv) Equivalent noise temperature.

(c) Write short note on V.S.B.

 

3. (a) Explain with help of circuitdiagram and waveforms high levelplatemodulator. 8

(b) Compare the followingamplitude modulated system: -12

DSB-FC, DSB-SC, SSB, VSB, ISB.

 

4. (a) Compare A.M. with EM.

(b) Compare narrow band EM. and wide band EM.

(c) Compare frequency modulation and phase modulation.

(d) Explain ED.M. with neat block diagram.

 

5. (a) What are the methods of EM. generation? Explainanyone. 10

(b) With the help of neat block diagram and waveforms explain superhetrodyne radio receiver. What are the advantages of thisreceiver over TRF radio receiver?

 

4.(a) Compare A.M. with EM.

(b) Compare narrow band EM. and wide band EM.

(c) Compare frequency modulation and phase modulation.

(d) Explain F.D.M. with neat block diagram.

 

5. (a) What are the methods of EM. generation? Explain anyone. 10

(b) With the help of neat block diagram and waveforms explain superhetrodyne radio receiver. What are the advantages of this receiver over TRF radio receiver?

 

6. (a) Explain phase discriminator EM. detector with the help of circuit diagram and phaser diagram.

(b) Explain PAM, PWM, PPM generation and detection.

 

 

7. (a) Draw the following line codes :-

(i) Unipolar NRZ

(ii) Unipolar RZ

(iii) Polar NRZ

(iv) Polar RZ

(v) A.M.I. (Bipolar).

(b) Draw the block diagram and explain PCM.

(c) Draw the block diagram of Adaptive delta modulation and explain it’s operation:

What are the advantages of this over delta modulation?

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