Firstranker's choice
Seat No.:
--- Content provided by FirstRanker.com ---
Subject Code:2151004
Enrolment No.
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER-V (NEW) EXAMINATION - WINTER 2018
Subject Name:Electronic and Communication
--- Content provided by FirstRanker.com ---
Time: 10:30 AM TO 01:00 PM
Instructions:
- Attempt all questions.
- Make suitable assumptions wherever necessary.
- Figures to the right indicate full marks.
--- Content provided by FirstRanker.com ---
Q.1 (a) Define Following Terms: MARKS 03
- Phase Modulation
- Modulation Index
- Image Frequency
(b) State and prove the following properties of Fourier transform. 04
--- Content provided by FirstRanker.com ---
- Time shifting
- Frequency shifting
(c) Define communication. Draw The basic block diagram of communication system explain the function of each block. 07
Q.2 (a) What is modulation and list out the need of modulation. 03
(b) State Parseval’s theorem. 04
--- Content provided by FirstRanker.com ---
(c) Draw and explain parallel tuned circuits in detail. Also derived equation for Resonance frequency and Q-factor for the parallel tuned circuits. 07
OR
(c) Write a short note on self-capacitance of a coil.
Q.3 (a) State and prove Time-scaling property of Fourier transform. 03
(b) An AM signal is represented by e(t) = (10+ 4 cos 800x t) cos (2nx103t) 04
--- Content provided by FirstRanker.com ---
Find: Modulation index, and transmission Bandwidth required for this AM signal.
(c) Explain Amplitude Modulation. with required waveforms. Also give mathematical representation of Amplitude modulated Wave. 07
OR
Q.3 (a) State and prove Duality property of Fourier transform. 03
(b) Two resistors 15 kO and 30 kO are at room temperature (290K) for a bandwidth of 300-kHz. Calculate thermal noise for each resistor, if two resistors are in series. 04
--- Content provided by FirstRanker.com ---
(c) Explain Phasing method for generation a SSBSC signal in detail. 07
Q.4 (a) Give Comparison between FM and AM system. 03
(b) With related to Amplitude modulation discuss following parameters: (I) Bandwidth requirement (II) Power distribution in sidebands and carrier. 04
(c) Describe briefly shot noise, partition noise and flicker noise with all details. 07
OR
--- Content provided by FirstRanker.com ---
Q.4 (a) Discuss drawbacks of direct method for FM generation. 03
(b) Draw the circuit diagram of delayed AGC. What are the advantages of delayed AGC? 04
(c) Derive Friis formula for noise factor of cascaded amplifier. 07
Q.5 (a) Explain what double spotting is and how it arises. 03
(b) Explain pre-emphasis and de-emphasis in relation to FM. 04
--- Content provided by FirstRanker.com ---
Date:07/12/2018 Total Marks: 70
(c) What tracking means in a superhetrodyne receiver? Explain three points tracking in radio receiver. 07
OR
Q.5 (a) Define the following terms related with radio receivers: (1) Selectivity (2) Fidelity (3) sensitivity 03
(b) Explain Phased Look Loop with all necessary details. 04
--- Content provided by FirstRanker.com ---
(c) Draw the block diagram of Tuned Radio Frequency (TRF) Receiver and explain its operation. Describe the problems in TRF receiver. 07
--- Content provided by FirstRanker.com ---
This download link is referred from the post: GTU BE/B.Tech 2018 Winter Question Papers || Gujarat Technological University