Communication System Important Questions

MCQ on Communication System:

Ques. In a communication system, noise is most likely to affect the signal
(a) At the transmitter
(b) In the channel or in the transmission line
(c) In the information source
(d) At the receiver

Ans. (b)

Ques. In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density 1011 per m
(a) 2 MHz
(b) 10 MHz
(c) 12 MHz
(d) 18 MHz

Ans. (a)

Ques. Advantage of optical fibre
(a) High bandwidth and EM interference
(b) Low bandwidth and EM interference
(c) High band width, low transmission capacity and no EM interference
(d) High bandwidth, high data transmission capacity and no EM interference

Ans. (d)

Ques. AM is used for broadcasting because
(a) It is more noise immune than other modulation systems
(b) It requires less transmitting power compared with other systems
(c) Its use avoids receiver complexity
(d) No other modulation system can provide the necessary bandwidth faithful transmission

Ans. (c)

Related: Measurement and Physical Quantities (Physics)

Ques. The total power content of an AM wave is 1500 W. For 100% modulation, the power transmitted by the carrier is
(a) 500 W
(b) 700 W
(c) 750 W
(d) 1000 W

Ans. (d)

Ques. Through which mode of propagation, the radio waves can be sent from one place to another
(a) Ground wave propagation
(b) Sky wave propagation
(c) Space wave propagation
(d) All of them

Ans. (d)

Ques. Audio signal cannot be transmitted because
(a) The signal has more noise
(b) The signal cannot be amplified for distance communication
(c) The transmitting antenna length is very small to design
(d) The transmitting antenna length is very large and impracticable

Ans. (d)

Ques. Long distance short-wave radio broadcasting uses
(a) Ground wave
(b) Ionospheric wave
(c) Direct wave
(d) Sky wave

Ans. (c)

Related: Set theory problems and solutions

Ques. In which of the following remote sensing technique is not used
(a) Forest density
(b) Pollution
(c) Wetland mapping
(d) Medical treatment

Ans. (d)

Ques. Maximum useable frequency (MUF) in F-region layer is x, when the critical frequency is 60 MHz and the angle of incidence is 70°. Then x is
(a) 150 MHz
(b) 170 MHz
(c) 175 MHz
(d) 190 MHz

Ans. (c)

Ques. The bit rate for a signal, which has a sampling rate of 8 kHz and where 16 quantisation levels have been used is
(a) 32000 bits/sec
(b) 16000 bits/sec
(c) 64000 bits/sec
(d) 72000 bits/sec

Ans. (a)

Ques. A laser beam is used for carrying out surgery because it
(a) is highly monochromatic
(b) is highly coherent
(c) is highly directional
(d) can be sharply focussed

Ans. (d)

Related: Redox Reactions Question Bank

Ques. An amplitude modulated wave is modulated to 50%. What is the saving in power if carrier as well as one of the side bands are suppressed
(a) 70%
(b) 65.4%
(c) 94.4%
(d) 25.5%

Ans. (c)

Ques. Basically, the product modulator is
(a) A mixer
(b) An amplifier
(c) A frequency separator
(d) A phase separator

Ans. (a)

Ques. While tuning in a certain broadcast station with a receiver, we are actually?
(a) Varying the local oscillator frequency
(b) Varying the frequency of the radio signal to be picked up
(c) Tuning the antenna
(d) None of these

Ans. (a)

About the author

Richa

Richa (B. Tech) has keen interest in Science and loves to teach students about it through lectures and assignments. She always try to use simple language and sentences while writing to make sure learner understands everything properly.

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