Top 150+ Solved Digital Communication MCQ Questions Answer
Q. The crest factor of a waveform is given as –
a. 2peak value/ rms value
b. rms value / peak value
c. peak value/ rms value
d. peak value/ 2rms value
Q. The digital modulation technique in which the step size is variedaccording to the variation in the slope of the input is called
a. delta modulation
b. pcm
c. adaptive delta modulation
d. pam
Q. The digital modulation scheme in which the step size is not fixed is
a. delta modulation
b. adaptive delta modulation
c. dpcm
d. pcm
Q. In Adaptive Delta Modulation, the slope error reduces and
a. quantization error decreases
b. quantization error increases
c. quantization error remains same
d. none of the above
Q. The number of voice channels that can be accommodated fortransmission in T1 carrier system is
a. 24
b. 32
c. 56
d. 64
Q. The maximum data transmission rate in T1 carrier system is
a. 2.6 megabits per second
b. 1000 megabits per second
c. 1.544 megabits per second
d. 5.6 megabits per second
Q. T1 carrier system is used
a. for pcm voice transmission
b. for delta modulation
c. for frequency modulated signals
d. none of the above
Q. Matched filter may be optimally used only for
a. gaussian noise
b. transit time noise
c. flicker
d. all of the above
Q. Matched filters may be used
a. to estimate the frequency of the received signal
b. in parameter estimation problems
c. to estimate the distance of the object
d. all of the above
Q. The process of coding multiplexer output into electrical pulses orwaveforms for transmission is called
a. line coding
b. amplitude modulation
c. fsk
d. filtering
Q. For a line code, the transmission bandwidth must be
a. maximum possible
b. as small as possible
c. depends on the signal
d. none of the above
Q. Regenerative repeaters are used for
a. eliminating noise
b. reconstruction of signals
c. transmission over long distances
d. all of the above
Q. Scrambling of data is
a. removing long strings of 1’s and 0’s
b. exchanging of data
c. transmission of digital data
d. all of the above
Q. In polar RZ format for coding, symbol ‘0’ is represented by
a. zero voltage
b. negative voltage
c. pulse is transmitted for half the duration
d. both b and c are correct
Q. Polar coding is a technique in which
a. 1 is transmitted by a positive pulse and 0 is transmitted by negative pulse
b. 1 is transmitted by a positive pulse and 0 is transmitted by zero volts
c. both a & b
d. none of the above