Digital Communications

Codes and Coding Technique

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which reduces the size of the data?
Source coding
Channel coding
Source & Channel coding
None of the mentioned
Explanation:
Source coding reduces the size of the data and channel coding increases the size of the data.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
In digital image coding which image must be smaller in size?
Input image
Output image
Input & Output image
None of the mentioned
Explanation:
In digital image coding, output image must be smaller than the input image.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
A rate distortion function is a
Concave function
Convex function
Increasing function
None of the mentioned
Explanation:
A rate distortion function is a monotone decreasing function and also a convex function.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Mutual information should be
Positive
Negative
Positive & Negative
None of the mentioned
Explanation:
Mutual information can also be negative.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which coding method uses entropy coding?
Lossless coding
Lossy coding
Lossless & Lossy coding
None of the mentioned
Explanation:
Lossy source coding uses entropy coding.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Which are uniquely decodable codes?
Fixed length codes
Variable length codes
Fixed & Variable length codes
None of the mentioned
Explanation:
Fixed length codes are uniquely decodable codes where as variable length codes may or may not be uniquely decodable.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Which achieves greater compression?
Lossless coding
Lossy coding
Lossless & Lossy coding
None of the mentioned
Explanation:
Lossy coding achieves greater compression where as lossless coding achieves only moderate compression.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
A code is a mapping from
Binary sequence to dicrete set of symbols
Discrete set of symbols to binary sequence
All of the mentioned
None of the mentioned
Explanation:
A code is a mapping from discrete set of symbols to finite binary sequence.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
While recovering signal, which gets attenuated more?
Low frequency component
High frequency component
Low & High frequency component
None of the mentioned
Explanation:
High frequency components are attenuated more when compared to low frequency components while recovering the signals.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
ASCII code is a
Fixed length code
Variable length code
Fixed & Variable length code
None of the mentioned
Explanation:
ASCII code is a fixed length code. It has a fixed length of 7 bits.