250+ TOP MCQs on Codes and Coding Technique & Answers

Digital Communications Multiple Choice Questions on “Codes and coding technique”.

1. While recovering signal, which gets attenuated more?
A. Low frequency component
B. High frequency component
C. Low & High frequency component
D. None of the mentioned
Answer: B
Clarification: High frequency components are attenuated more when compared to low frequency components while recovering the signals.

2. Mutual information should be
A. Positive
B. Negative
C. Positive & Negative
D. None of the mentioned
Answer: C
Clarification: Mutual information can also be negative.

3. ASCII code is a
A. Fixed length code
B. Variable length code
C. Fixed & Variable length code
D. None of the mentioned
Answer: A
Clarification: ASCII code is a fixed length code. It has a fixed length of 7 bits.

4. Which reduces the size of the data?
A. Source coding
B. Channel coding
C. Source & Channel coding
D. None of the mentioned
Answer: A
Clarification: Source coding reduces the size of the data and channel coding increases the size of the data.

5. In digital image coding which image must be smaller in size?
A. Input image
B. Output image
C. Input & Output image
D. None of the mentioned
Answer: B
Clarification: In digital image coding, output image must be smaller than the input image.

6. Which coding method uses entropy coding?
A. Lossless coding
B. Lossy coding
C. Lossless & Lossy coding
D. None of the mentioned
Answer: B
Clarification: Lossy source coding uses entropy coding.

7. Which achieves greater compression?
A. Lossless coding
B. Lossy coding
C. Lossless & Lossy coding
D. None of the mentioned
Answer: B
Clarification: Lossy coding achieves greater compression where as lossless coding achieves only moderate compression.

8. A code is a mapping from
A. Binary sequence to dicrete set of symbols
B. Discrete set of symbols to binary sequence
C. All of the mentioned
D. None of the mentioned
Answer: B
Clarification: A code is a mapping from discrete set of symbols to finite binary sequence.

9. Which are uniquely decodable codes?
A. Fixed length codes
B. Variable length codes
C. Fixed & Variable length codes
D. None of the mentioned
Answer: A
Clarification: Fixed length codes are uniquely decodable codes where as variable length codes may or may not be uniquely decodable.

10. A rate distortion function is a
A. Concave function
B. Convex function
C. Increasing function
D. None of the mentioned
Answer: B
Clarification: A rate distortion function is a monotone decreasing function and also a convex function.