Digital Communications

Modulation and Multiplexing

Question 1
Marks : +2 | -2
Pass Ratio : 100%
When probability of receiving a symbol is 1 then how much information will be obtained?
Little information
Much information
No information
None of the mentioned
Explanation:
When the probability of receiving a symbol is 1 then the information obtained is zero.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
In channel encoding procedure
Redundancy bits are added
Errors are corrected
Redundancy bits are added & Errors are corrected
None of the mentioned
Explanation:
In channel encoding includes addition of redundancy to the signal such that any bit errors can be corrected.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Modulation process includes
Analog to digital conversion
Digital to analog conversion
All of the mentioned
None of the mentioned
Explanation:
Modulation procedure includes digital to analog conversion which produces a continuous time signal that can be sent through the channel.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
In bipolar codes, pulses can be
Positive
Negative
Absent
All of the mentioned
Explanation:
In bipolar codes, the pulses can be positive, negative or absent.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Switching exists in
Point to point communication
Broadcast communication
Point to point & Broadcast communication
None of the mentioned
Explanation:
Circuit connection in point to point communication is called as switching. Switching does not exist in broadcast communication or network.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Properties used to determine stream’s fidelity
Sampling rate
Bit depth
Sampling rate & Bit depth
None of the mentioned
Explanation:
Two basic properties to determine stream’s fidelity are bit depth and sampling rate, number of times per second that samples are taken.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
The demodulator in delta modulation technique is
Differentiator
Integrator
Quantizer
None of the mentioned
Explanation:
The demodulator used in delta modulation is a simple form of integrator.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
To achieve high signal to noise ratio, delta modulation must use
Under sampling
Over sampling
Aliasing
None of the mentioned
Explanation:
To achieve high signal to noise ratio, delta modulation must use over sampling techniques.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Source of noise in delta modulation is
Granularity
Slope overload
Granularity & Slope overload
None of the mentioned
Explanation:
Sources of noise in delta modulation are granularity and slope overload.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Delta modulation is ______ conversion.
Analog to digital
Digital to analog
Analog to digital and digital to analog
None of the mentioned
Explanation:
Delta modulation is the process of analog to digital and digital to analog conversion technique used for transmission of voice signals.