PHE-16 EM 2024 SOLVED ASSIGNMENT

Description

Tutor Marked Assignment
COMMUNICATION PHYSICS
Course Code : PHE-16
Assignment Code: PHE-16/TMA/2024
Max. Marks: 100
Note: Attempt all questions. Symbols have their usual meanings. The marks for each
question are indicated against it.
1. State with reasons whether the following statements are True or False. (210)
i) The best mode for transmitting optical signal is Line-of-Sight communication.
ii) A simple sine wave signal does not carry any information.
iii) Input impedance for an open ended transmission line of /2 length is zero.
iv) Amplitude distortion in AM gives rise to unwanted frequency components.
v) Amplitude shift keying is modulation of digital carrier by analog signal.
vi) Mobile telephony uses time division multiplexing.
vii) Gunn devices can be built using indirect band gap semiconductors.
viii) In television, vertical scanning frequency is higher than horizontal scanning
frequency.
ix) Machine language programmes are portable, while assembly language
programmes are not.
x) Router can provide inter-conversion of protocols among connections.
2. a) What are the characteristics of the first stage amplifier of an audio receiver circuit? (5)
b) Explain the use of step input signal in characterizing a communication system. Why
square wave signal is preferred over step input signal? (4+1)
3. a) For a conductor, number of collisions per second is 1012, and plasma frequency is
p = 2  1015. Calculate the skin depth for the signal frequency of (i) 50 Hz, and
(ii) 50 MHz. (3+2)
b) You have an open ended line of 3/4 length. Draw the incident, reflected and
resultant voltage and current waves for the current maximum at generator end. (5)
4. a) 10 kHz audio signal is amplitude modulated over a 100 kHz carrier frequency. The
peak amplitude of carrier wave is 10 V. If the modulation index is 0.8, find out the
frequencies present in the modulated output. Also calculate the maximum and the
minimum amplitude of the envelope of modulated signal. (5)
b) Depict digital signal 101101001 in (i) unipolar RZ, (ii) bipolar NRZ, (iii) bipolar
RZ, and (iv) Manchester code. (1+1+1+2)
5. a) Explain the time division switching used in telephony. (5)
b) Design a TDM system to handle 3 PAM channels if the maximum input frequency
of each channel is 50 kHz. (5)
4
6. a) What are the functions of synchronizing circuits in a television receiver? How are
these functions accomplished by using a sync separator circuit? (2+3)
b) Discuss the advantages of FM over AM in radio transmission. What are the
essential differences between AM and FM receiver circuits? (3+2)
7. a) With the help of appropriate diagram, explain the difference between E-plane and
H-plane T-structures of the waveguide. (5)
b) Compare LED and laser diode used as sources in optical fibre communication. (5)
8. a) Explain the process of instruction execution in a van Neumann machine. (5)
b) Explain the different types of client-server network architecture. (5)
9. a) What is the difference between Internet and intranet? What are the advantages of
intranet? (2+3)
b) What is blue tooth technology? What are the concerns regarding the interference
among blue tooth connections? How are they resolved?