NEET Physics Communication System MCQs Set A

Question: Which of the following is the element of a communication system?
a) All of the above
b) channel
c) Transmitter
d) Receiver
Answer: All of the above

Question: A transducer used at the transmitting end, serves the purpose of converting
a) sound signal to electrical form
b) electrical signal to sound form
c) electrical signal to magnetic form
d) sound signal to magnetic form
Answer: sound signal to electrical form

Question: The term channel is used to indicate
a) the frequency range allocated to a given source
b) the voltage-range allocated to a given source
c) All of the above
d) the amplitude range allocated to a given source
Answer: the frequency range allocated to a given source

Question: Buffer amplifier is used at the transmitting end to
a) isolate master oscillator from other stages of transmitter
b) mix modulating signal with carrier frequency
c) amplify carrier frequency
d) feed carrier frequency to master oscillator
Answer: isolate master oscillator from other stages of transmitter

Question: The purpose of a detector at the receiving end is
a) to demodulate signal
b) to modulate signal
c) to reduce its frequency level
d) to amplify signal
Answer: to demodulate signal

Question: Modem is a short form of
a) modulator-demodulator
b) multiplexer-demultiplexer
c) multivibrator-degenerator
d) None of these
Answer: modulator-demodulator

Question: Ground wave propagation is possible for
a) low radio frequency over a short range
b) high radio frequency over a short range
c) high radio frequency over a long range
d) low radio frequency over a short range
Answer: low radio frequency over a short range

Question: Long range transmission of TV-signal is done by
a) artificial satellite
b) sky waves
c) space-wave
d) ground wave
Answer: artificial satellite

Question: Long range propagation is not possible by space wave propagation because
a) height of troposhere is quite small
b) height of troposhere is large
c) troposphere absorbs transmitted wave
d) None of these.
Answer: height of troposhere is quite small

Question: Critical frequency that gets reflected back from ionosphere is
a) different for different layers of the ionosphere
b) not dependent on layers of the ionosphere
c) None of these
d) same for all layers of the ionosphere
Answer: different for different layers of the ionosphere

Question: Encoding of signal is required for
a) modulation at transmitting end
b) modulation at receiving end
c) demodulation at receiving end
d) demodulation at transmitting end
Answer: modulation at transmitting end

Question: Communication on ground is through electromagnetic waves of wavelength
a) between 10 ^{– 3} and 0.1
b) between 1 and 5 m
c) between 200 and 600 m
d) larger than 600 m
Answer: between 10 ^{– 3} and 0.1

Question: During ground wave propagation the transmitted waves gets attenuated because
a) earth surface offers resistance
b) energy content of these waves are high
c) frequency of the waves are too low
d) earth surface absorbs the waves
Answer: earth surface offers resistance

Question: Wave obtained on superimposition of audible frequency e.m. wave is known as
a) modulated wave
b) high frequency wave
c) modulating wave
d) carrier wave
Answer: modulated wave