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This set of Digital Communication Multiple Choice Questions & Answers (MCQs) focuses on Digital Communication Set 2
Q1 | Matched filters may be used
- to estimate the frequency of the received signal
- in parameter estimation problems
- to estimate the distance of the object
- all of the above
Q2 | The process of coding multiplexer output into electrical pulses orwaveforms for transmission is called
- line coding
- amplitude modulation
- fsk
- filtering
Q3 | For a line code, the transmission bandwidth must be
- maximum possible
- as small as possible
- depends on the signal
- none of the above
Q4 | Regenerative repeaters are used for
- eliminating noise
- reconstruction of signals
- transmission over long distances
- all of the above
Q5 | Scrambling of data is
- removing long strings of 1’s and 0’s
- exchanging of data
- transmission of digital data
- all of the above
Q6 | In polar RZ format for coding, symbol ‘0’ is represented by
- zero voltage
- negative voltage
- pulse is transmitted for half the duration
- both b and c are correct
Q7 | Polar coding is a technique in which
- 1 is transmitted by a positive pulse and 0 is transmitted by negative pulse
- 1 is transmitted by a positive pulse and 0 is transmitted by zero volts
- both a & b
- none of the above
Q8 | The polarities in NRZ format use
- complete pulse duration
- half duration
- both positive as well as negative value
- each pulse is used for twice the duration
Q9 | The format in which the positive half interval pulse is followed by anegative half interval pulse for transmission of ‘1’ is
- polar nrz format
- bipolar nrz format
- manchester format
- none of the above
Q10 | The maximum synchronizing capability in coding techniques ispresent in
- manchester format
- polar nrz
- polar rz
- polar quaternary nrz
Q11 | The advantage of using Manchester format of coding is
- power saving
- polarity sense at the receiver
- noise immunity
- none of the above
Q12 | Alternate Mark Inversion (AMI) is also known as
- pseudo ternary coding
- manchester coding
- polar nrz format
- none of the above
Q13 | In DPSK technique, the technique used to encode bits is
- ami
- differential code
- uni polar rz format
- manchester format
Q14 | Overhead bits are
- framing and synchronizing bits
- data due to noise
- encoded bits
- none of the above
Q15 | ISI may be removed by using
- differential coding
- manchester coding
- polar nrz
- none of the above
Q16 | Timing jitter is
- change in amplitude
- change in frequency
- deviation in location of the pulses
- all of the above
Q17 | Probability density function defines
- amplitudes of random noise
- density of signal
- probability of error
- all of the above
Q18 | Impulse noise is caused due to
- switching transients
- lightening strikes
- power line load switching
- all of the above
Q19 | In coherent detection of signals,
- local carrier is generated
- carrier of frequency and phase as same as transmitted carrier is generated
- the carrier is in synchronization with modulated carrier
- all of the above
Q20 | Synchronization of signals is done using
- pilot clock
- extracting timing information from the received signal
- transmitter and receiver connected to master timing source
- all of the above
Q21 | Orthogonality of two codes means
- the integrated product of two different code words is zero
- the integrated product of two different code words is one
- the integrated product of two same code words is zero
- none of the above
Q22 | In Alternate Mark Inversion (AMI) is
- 0 is encoded as positive pulse and 1 is encoded as negative pulse
- 0 is encoded as no pulse and 1 is encoded as negative pulse
- 0 is encoded as negative pulse and 1 is encoded as positive pulse
- 0 is encoded as no pulse and 1 is encoded as positive or negative pulse
Q23 | Advantages of using AMI
- needs least power as due to opposite polarity
- prevents build-up of dc
- may be used for longer distance
- all of the above
Q24 | The interference caused by the adjacent pulses in digital transmissionis called
- inter symbol interference
- white noise
- image frequency interference
- transit time noise
Q25 | Eye pattern is
- is used to study isi
- may be seen on cro
- resembles the shape of human eye
- all of the above