Deemed University 2009 M.Tech Information Technology University: Lingayas University Term: I Title of the : Communication System - Question Paper
Roll No. ..
Lingayas University, Faridabad
M.Tech (Information Technology (Term I)
End Term Examination October, 2009
Course: Communication System
Course Code: IT -501
[Time: 3 Hours] [Max. Marks: 100]
Before answering the question, candidate should ensure that they have been supplied the correct and complete question paper. No complaint in this regard, will be entertained after examination.
Note: All questions carry equal marks. Attempt five questions. Question one is compulsory. Select two questions from Section B and two from Section C.
SECTION A
Q-1 Part- A
Select the correct answer of the following multiple choice questions
(i) Half duplex transmission mode is
(a) Uni-direction (b) Bi-direction (c) Forward (d) Backward
(ii) In Star topology, each device needs link
(a) one (b) two (c) three (d) four
(iii) WAN is the transmission mode
(a) Synchronous (b) asynchronous (c) Parallel (d) Serial
(iv) Channel capacity of noise fee channel heaving m symbols is given by
(a) log m (b) m (c) 2m (d) none
(v) A port address in TCP/IP is __________bits in length
(a) 32 (b) 16 (c) 48 (d) 56
(vi) An Analog signal carries 4 bits per second/signal element if 1000 signal element one sent per second then the bit rate
(a) 4000 bps (b) 5000 bps (c) 6000 bps (d) 7000 bps
(vii) Range of modulation index in Am is
(a) 0 to 2 (b) 0 to 1 (c) 0 to 5 (d) 0 to 6
(viii)QAM is said to be extension of
(a) ASK (b) FSK (c) QPSK (d) PSK
(ix) Magnitude spectrum of Fourier transform of real valued time signal has
(a) odd symmetry (b) even symmetry (c) conjugate symmetry
(x) Bandwidth needed by DM is less than
(a) PCM (b) ACM (c) FCM
(xi) The simplest form of FSK, also called as
(a) BFSK (b) AFSK (c) DFSK
(xii) Information content in a Universally True event is
(a) infinite (b) zero (c) positive (d) negative
(xiii) As the bandwidth approaches infinity, the channel capacity becomes
(a) zero (b) infinite (c) 1.44s/n (d) none
(xiv) The efficiency of Huffman code is linearly proportional to
(a) Average length of code (b) Maximum length of code
(c) Average extropy
(xv) Cyclic code is subclass of convolutional code
(a) True (b) False
(xvi) Figure of merit is always unity in
(a) SSB-SC (b) AM (c) FM (d) all the three
(xvii) The message carrying efficiency is best in
(a) FM (b) AM (c) AM-SC (d) PM
(xviii) In a commercial FM broadcast system, the Modulatry Signal frequency is limited to about
(a) 3.4 khz (b) 5khz (c) 15khz (d) 20khz
(xix) A carrier is amplitude modulatory to depth of 40%. The increase in power is
(a) 40% (b) 20% (c) 16% (d) 8%
(xx) The coding efficiency is given by
(a) 1-redundancy (b) 1+redundancy
(c) 1/redundancy (d) none (x20)=10
Q-1. Part - B
(a) What do you understand by data communications? Explain the four fundamental characteristics of data communication. (5)
(b) Compare Analog and Digital Modulation. (5)
SECTION - B
Q-2. What is TCP/IP model. Explain the function of each layer. (20)
Q-3. What do you understand by modulation. Explain the spectrum of AM wave. (20)
Q-4. Explain companding in detail. (20)
P.T.O.
SECTION C
Q-5. Explain the time shifting and frequency shifting properties of Fourier transform in detail. (20)
Q-6. A broadcast radio transmitter radiates 10 kw when modulation percentage is 60%. How much of this the conquer power. (20)
Q-7. Explain PCM in detail with suitable example. (20)
Q-8. Explain Shannons coding and Huffman coding with suitable examples. (20)
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