TED (21)3042 Reg.No.....................................
2110220233
(Revision-2021) Signature..................................
DIPLOMA EXAMINATION IN ENGINEERING/TECHNOLOGY/MANAGEMENT/
COMMERCIAL PRACTICE, NOVEMBER - 2023
PRINCIPLES OF ELECTRONIC COMMUNICATION
[Maximum marks: 75] [Time: 3 Hours]
PART A
I. Answer all the following questions in one word or one sentence. Each question carries 1 mark
(9 x 1 = 9 Marks)
Module Cognitive
outcome level
1 The process of changing the parameters of the carrier signal, in accordance M1.01 R
with the instantaneous amplitude of message signal is called as …..
2 Name the modulation scheme used for the transmission of television signals. M1.02 R
3 List any two pulse modulation schemes. M2.02 R
4 Define radiation intensity. M2.03 R
5 What is the VHF band range of FM transmitter? M3.01 R
6 Balanced Modulator is used to generate………. M3.02 R
7 Define SNR M3.03 R
8 List any two characteristics of radio receiver. M4.01 R
9 Diode detector is also called as…….. M4.03 R
PART B
II. Answer any eight questions from the following. Each question carries 3 marks.
(8 x 3 = 24 Marks)
Module Cognitive
outcome level
1 List any three applications of FM M1.01 R
2 State sampling theorem with mathematical expression. M2.01 R
3 Explain the need for pre-emphasis. M3.01 U
4 Draw the block diagram of balanced modulator M3.02 R
5 Define noise. List various types of noises. M3.03 R
6 Draw the circuit diagram and characteristics of de-emphasis. M3.01 R
1
7 Define the following terms: (1)Fidelity (2) Noise Figure M4.01 R
8 Draw the block diagram of AM receiver. M4.02 R
9 Why delayed AGC is better than simple AGC? M4.03 R
10 Compare AM and FM receiver. M4.02 U
PART C
Answer all questions. Each question carries seven marks
(6 x 7 = 42 Marks)
Module Cognitive
outcome level
III The peak amplitude of AM signal varies from 2v to 10v. Determine M1.04 A
the modulation index, carrier power, side band power and total power.
OR
IV The FM signal is represented as s(t) = 10cos[2П106t+8sin4П103t]. M1.04 A
Calculate modulation index, frequency deviation, bandwidth and
power.
V Derive the expression of an AM wave. M1.03 U
OR
VI Explain the need of modulation. M1.01 U
VII Explain the working of PWM modulator with circuit diagram and M2.02 U
waveforms.
OR
VIII With a neat sketch explain microstrip antenna. M2.03 U
IX Illustrate the concept of electromagnetic radiation. M2.03 U
OR
X
Draw the circuit diagram and waveforms of PAM modulator and M2.02 U
explain its working.
XI Explain the block diagram of indirect method of an FM transmission. M3.01 U
OR
XII With circuit diagram explain the working of AM collector modulator M3.02 U
circuit.
XIII Explain the block diagram of Superhetrodyne receiver. M4.02 U
OR
XIV Illustrate the operation of diode detector with circuit diagram M4.03 U
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