Deck 2: Information Theory and Communication Techniques

Question 1

If the channel is noiseless information conveyed is        and if it is useless channel information conveyed is        

A)0,0
B)1,1
C)0,1
D)1,0

Answer 1

1,0

Question 2

The mutual information between a pair of events is

A)positive
B)negative
C)zero
D)all of the mentioned

Answer 2

all of the mentioned

Question 3

The output of an information source is

A)random
B)deterministic
C)random & deterministic
D)none of the mentioned

Answer 3

random

Question 4

When the base of the logarithm is e, the unit of measure of information is

A)bits
B)bytes
C)nats
D)none of the mentioned

Question 5

Flat top sampling of low pass signals

A)gives rise to aperture effect
B)implies over sampling
C)leads to aliasing
D)introduces delay distortion

Question 6

In a delta modulation system, granular noise occurs when the

A)modulating signal increases rapidly
B)pulse rate decreases
C)pulse amplitude decreases
D)modulating signal remains constant

Question 7

A PAM signal can be detected using

A)low pass filter
B)high pass filter
C)band pass filter
D)all pass filter

Question 8

Coherent demodulation of FSK signal can be performed using

A)matched filter
B)bpf and envelope detectors
C)discriminator
D)none of the mentioned

Question 9

The use of non uniform quantization leads to

A)reduction in transmission bandwidth
B)increase in maximum snr
C)increase in snr for low level signals
D)simplification of quantization process

Question 10

A PWM signal can be generated by

A)an astable multi vibrator
B)a monostable multi vibrator
C)integrating a ppm signal
D)differentiating a ppm signal

Question 11

TDM is less immune to cross-talk in channel than FDM.

Question 12

In an ideal TDM system, the cross correlation between two users of the system is

A)1
B)0
C)infinity
D)-1

Question 13

TDM requires

A)constant data transmission
B)transmission of data samples
C)transmission of data at random
D)transmission of data of only one measured

Question 14

Which waveforms are also called as line codes?

A)pcm
B)pam
C)fm
D)am

Question 15

When pulse code modulation is applied to non binary symbols we obtain waveform called as

A)pcm
B)pam
C)m-ary
D)line codes

Question 16

Examples of PCM waveforms are

A)non return to zero
B)phase encoded
C)multilevel binary
D)all of the mentioned

Question 17

Which type is used and preferred in digital logic circuits?

A)nrz-l
B)nrz-m
C)nrz-s
D)none of the mentioned

Question 18

Which method is called as differential encoding?

A)nrz-l
B)nrz-m
C)nrz-s
D)none of the mentioned

Question 19

Which method is preferred in magnetic tape recording?

A)nrz-l
B)nrz-m
C)nrz-s
D)none of the mentioned

Question 20

NRZ-S is complement of_________    

A)nrz-l
B)nrz-m
C)nrz-l & nrz-m
D)none of the mentioned

Question 21

The return to zero waveform consists of

A)unipolar rz
B)bipolar rz
C)rz-ami
D)all of the mentioned

Question 22

Phase encoded group consists of

A)manchester coding
B)bi-phase-mark
C)miller coding
D)all of the mentioned

Question 23

In which waveform logic 1 is represented by half bit wide pulse and logic 0 is represented by absence of pulse?

A)unipolar rz
B)bipolar rz
C)rz-ami
D)manchester coding

Question 24

In which waveform logic 1 and logic 0 are represented by opposite one half bit wide pulses?

A)unipolar rz
B)bipolar rz
C)rz-ami
D)manchester coding