Digital Communications

Baseband Transmission

Question 1
Marks : +2 | -2
Pass Ratio : 100%
The return to zero waveform consists of
Unipolar RZ
Bipolar RZ
RZ-AMI
All of the mentioned
Explanation:
Different types of return to zero waveforms are unipolar RZ, bipolar RZ, RZ-AMI. These are used in baseband transmission and in magnetic recording.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Which method is preferred in magnetic tape recording?
NRZ-L
NRZ-M
NRZ-S
None of the mentioned
Explanation:
NRZ-M is also called as differential encoding and it is most preferred in magentic tape recording.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Which waveforms are also called as line codes?
PCM
PAM
FM
AM
Explanation:
When pulse modulation is applied to binary symbol we obtain pulse code modulated waveforms. These waveforms are also called as line codes.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
In which waveform logic 1 is represented by half bit wide pulse and logic 0 is represented by absence of pulse?
Unipolar RZ
Bipolar RZ
RZ-AMI
Manchester coding
Explanation:
In unipolar RZ waveform, logic 1 is represented by half bit wide pulse and logic 0 is represented by the absence of a pulse.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which method is called as differential encoding?
NRZ-L
NRZ-M
NRZ-S
None of the mentioned
Explanation:
In NRZ-M, logic 1 is represented by a change in voltage level and logic 0 is represented by no change in level. This is called as differential encoding.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Phase encoded group consists of
Manchester coding
Bi-phase-mark
Miller coding
All of the mentioned
Explanation:
Different types of phase encoded waveform consists of manchester coding, bi-phase-mark, bi-phase-space, delay modulation.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Examples of PCM waveforms are
Non return to zero
Phase encoded
Multilevel binary
All of the mentioned
Explanation:
Some of the examples or classification of pulse code modulated signals are non return to zero, return to zero, phase encoded, multilevel binary etc.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
When pulse code modulation is applied to non binary symbols we obtain waveform called as
PCM
PAM
M-ary
line codes
Explanation:
When pulse code modulation is applied to binary symbols we get PCM waveforms and when it is applied to non binary symbols we obtain M-ary waveforms.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
NRZ-S is complement of _______
NRZ-L
NRZ-M
NRZ-L & NRZ-M
None of the mentioned
Explanation:
NRZ-S is a complement of NRZ-M. Logic 0 is represented by a change in voltage level and logic 1 is represented as no change in voltage level.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Which type is used and preferred in digital logic circuits?
NRZ-L
NRZ-M
NRZ-S
None of the mentioned
Explanation:
NRZ-L is extensively used in digital logic circuits. In this method, logic 1 is represented by one voltage level and logic 0 is represented by another voltage level.