www.pdfquestion.in

Name of the College : Northern India Engineering College
University : Guru Gobind Singh Indraprastha University
Subject Code/Name : ETEC-208/Communication Circuit And System
Dept : Electronics And Communication Engineering
Degree : BE
Sem: IV
Website : gtbit.org
Document Type : Question Bank

Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/gtbit.org/3366-ccssem4qbank.doc

GTBIT Communication Circuit & System Question Paper

1. Communication is the process of
(a) Keeping in touch
(b) Braodcasting

Related : Northern India Engineering College ETCS207 Analog Electronics B.E Question Bank : www.pdfquestion.in/3367.html

(c) Exchanging information
(d) Entertainment by electronics

2. Two key barrier to human communication are
(a) Distance
(b) Cost
(c) Ignorance
(d) Language

3. The higher modulating frequency used in AM broadcast
system is
(a) 10 KHz
(b) 15 KHz
(c) 5 kHz
(d) 2 MHz

4. The higher frequency (HF) range extends from
(a) 300-3000KHz
(b) 3-30 KHz
(c) 30-300 MHz
(d) 3000-30000MHz

5. The Very high frequency(VHF) range extends from
(a) 300-3000KHz
(b) 3-30 KHz
(c) 30-300 MHz
(d) 3000-30000MHz

6. The ultra high frequency (UHF) range extends from
(a) 300-3000KHz
(b) 3-30 KHz
(c) 30-300 MHz
(d) 3000-30000MHz

7. Radio signals are made up of
(a) voltage and current
(b) electric and magnetic fields
(c) electrons and protons
(d) noise and data

8.The communication medium causes the signal to be
(a) amplifier
(b) modulated
(c) attenuted
(d) interferrred with

9. The function of the input transducer in a communication system is
(a) to transmit the message signal
(b) to modulate the message signal
(c) to convert message sound signal into electrical signal
(d) none of the above

10. Which of the following is not a major communication medium
(a) free space
(b) water
(c) wires
(d) fibber optics cable

11. The process of trnsmitting two or more information signals simultaneously over the same channel is called
(a) multiplexing
(b) telemetry
(c) detection
(d) modulation

12. In amplitude modulation
(a)The amplitude of carrier varies in accordance with the
amplitude of the modulating signal
(b)The modulating frequency lies in the audio range
(c)The amplitude of the carrier remains constant
(d)The amplitude of the carrier varies in accordance with the frequency of the modulating signal

13. A carrier is simultaneously modulated by two sine waves having modulation Indices of 0.4 and 0.3-. The total modulation index will be
(a) 0.1
(b) 0.7
(c) 0.5
(d) 0.35

14. In AM the total modulation index must not exceed unity or else
(a) The system will fail
(b) Distortion will result
(c) Amplifier will be damaged
(d) Resonant waves will be generated

15. A 400 W carrier is modulated to a depth of 75 percent The total power in modulated wave will be
(a) 385.5 W
(b) 400 W
(c) 512.5 W
(d) 615.5 W

16. The percentage saving in power of 100% modulated suppressed carrier AM signal is
(a) 100
(b) 75
(c) 66.7
(d) 50

17. In amplitude modulation, the modulation index lies between
(a) –1 and 1
(b) 0 and 1
(c) 1 and infinity
(d) -8 and + 8

18. The bandwidth required for amplitude modulation is
(a) Half the frequency of modulating signal
(b) Equal to the frequency of modulating signal
(c) Twice the frequency of modulating signal
(d) Four times the frequency of modulating signal

19. In a single side band suppressed carrier AM system the modulation index is changed from 0 to 1, the power content of the signal
(a) Will be quadrupled
(b) Will be doubled
(c) Will increase by 50 percent
(d) Will increase by 25 percent

20. In modulation “carrier” is
(a) Resultant wave
(b) Speech voltage to be transmitted
(c) Voltage with constant frequency phase or amplitude
(d) Voltage for which frequency, phase or amplitude is varied

21. In amplitude modulation the magnitude of side bands is
(a) ma/2 times the carrier
(b) ma times the carrier amplitude
(c) 2ma times the carrier amplitude
(d) 4ma times the carrier amplitude

22. For a low level AM system the amplifiers following the modulated stage must be
(a) Linear devices
(b) Harmonic devices
(c) Class C amplifier
(d) Non linear devices

23. When Ec & Em are the peak values of modulating & carrier voltages respectively, the Modulating index is given by
(a) Em/Ec
(b) Ec/Em
(c) Em Ec
(d) None of the above

24. In an amplitude modulated wave, the amplitude of the side band is
(a) Independent of the carrier amplitude
(b) Independent of the modulation index
(c) Carrier amplitude X modulation index
(d) ½ carrier amplitude X modulation index

25. Noise which assumes great importance is
(a) Flicker noise.
(b) Johnson noise
(c) Transit time noise
(d) Shot noise