|
Download Model question papers & previous years question papers
|
Posted Date: 02 Jun 2012 Posted By:: Niral Patel Member Level: Gold Points: 5 (Rs. 1)
|
2010 Rashtrasant Tukadoji Maharaj Nagpur University B.E Electronics & Communication Engineering Winter 2010, Faculty of Engineering and Technology, COMMUNICATION ELECTRONICS Question paper
Section A
1. (a) List the different types of noise existing in a receiver circuit. Explain each of them.
(b) Explain noise figure and derive the equation for the same for a two stage amplifier.
(c) Why is high frequency carrier required for a communication system?
2. (a) Explain following terms as related to ionospheric propagation:
(i) Critical frequency
(ii) MUF
(iii) Skip distance
(b) Explain tropospheric wave propagation. Also derive the expression for range of tropospheric propagation.
3. (a) Explain plate modulated class-C amplifier with the help of circuit diagram.
(b) With the help of block diagram explain as to how SSB-SC signal is generated by phase shift method.
4. (a) What is frequency modulation? Derive the expression for the instantaneous value of FM signal. Also draw necessary waveforms and comment on the significant side bands in FM.
(b) An AM signal has the equation:
V(t)= {[ 15 + 4sin??(44*?10?^3 t)] sin??46.5*?10?^6 t]V? ?
Find:
(i) Carrier frequency
(ii) Frequency of modulating signal
(iii) Modulation index
(iv) Sketch the signal in time domain and in frequency domain
(v) Transmission efficiency.
5. (a) Draw the circuit diagram of square law diode detector and explain its working with suitable diagram.
(b) Draw the complete block diagram of the Armstrong frequency modulation system and explain the function of the miner, multiplier and balanced modulator.
Section B
6. (a) Explain generation of PWM signal. How it is demodulated?
(b) Explain generation of PPM and explain with waveforms how it is derived from PWM.
7. (a) Draw and explain the block diagram of superheterodyne radio receiver.
(b) Explain PCM with neat waveforms. Also explain Quantization in brief.
8. (a) Draw the block diagram of communication receiver and explain the working of Squelch system in detail.
(b) Define the following terms with respect to radio receiver:
(i) Sensitivity
(ii) Selectivity
(iii) Image frequency rejection
9. (a) Explain telephone transmitter and telephone receiver circuit in detail.
(b) Write the different tones used in automatic exchange.
(c) Explain time division multiplexing used in telephony.
10. (a) Write short notes on any TWO:
(i) Adaptive Delta Modulation
(ii) Double spotting
(iii) Central Battery Exchange.
Return to question paper search
|
|
|
Submit Previous Years University Question Papers and make money from adsense revenue sharing program
Are you preparing for a university examination? Download model question papers
and practise before you write the exam.
|
|