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DR. BABASAHEB AMBEDKAR TECHNOLOGICAL UNIVERSITY, LONERE –
RAIGAD 402 103
Semester Examination – May  2019


Branch: Electronics and Telecommunication Engineering
Sem.: IV
Subject with Subject Code: Analog Communication Engineering Marks: 60
BTEXC402]
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Date: 16/05/2019
Time: 3 Hr.
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Instructions to the Students
1
2
3
4
. Each question carries 12 marks.
. Attempt any five questions of the following.
. Illustrate your answers with neat sketches, diagram etc., wherever necessary.
. If some part or parameter is noticed to be missing, you may appropriately
assume it and should mention it clearly
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(Marks)
Q.1. A) State and explain Sampling Theorem. What is Nyquist (06)
Criteria? A continuous time signal x (t) = 7 sin 2500πt + 5 sin
7
500πt is to be sampled. Calculate the minimum sampling
frequency.
B) With the help of neat diagram explain a typical radio (06)
transmitter.
Q.2. A) Explain double sideband suppressed carrier technique of AM. (12)
Also explain generation of the same using Balanced Modulator.
OR
B) 1. Derive an expression for power relation in an AM wave. (06)
Assuming that a 750 W carrier is modulated to the depth of
5
0 percent. Calculate the total power in modulated wave.
2
. Explain VSB technique of AM, What are its advantages over (06)
other AM Techniques
Q.3.
Answer any two of the following
A) Explain generation of Frequency modulation with the help of (06)
basic reactance modulator.
B) In an FM system, when the audio frequency (AF) is 750 Hz, and (06)
AF voltage is 2.6 V, the deviation is 5.2 kHz. If the AF voltage is
now increased to 8V what is new deviation? If the AF voltage is
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