Digital Communications Multiple Choice Questions on “Information and Coding”.
1. Self information should be
A. Positive
B. Negative
C. Positive & Negative
D. None of the mentioned
Answer: A
Clarification: Self information is always non negative.
2. The unit of average mutual information is
A. Bits
B. Bytes
C. Bits per symbol
D. Bytes per symbol
Answer: A
Clarification: The unit of average mutual information is bits.
3. When probability of error during transmission is 0.5, it indicates that
A. Channel is very noisy
B. No information is received
C. Channel is very noisy & No information is received
D. None of the mentioned
Answer: C
Clarification: When probability of error during transmission is 0.5 then the channel is very noisy and thus no information is received.
4. Binary Huffman coding is a
A. Prefix condition code
B. Suffix condition code
C. Prefix & Suffix condition code
D. None of the mentioned
Answer: A
Clarification: Binary Huffman coding is a prefix condition code.
5. The event with minimum probability has least number of bits.
A. True
B. False
Answer: B
Clarification: In binary Huffman coding the event with maximum probability has least number of bits.
6. The method of converting a word to stream of bits is called as
A. Binary coding
B. Source coding
C. Bit coding
D. Cipher coding
Answer: B
Clarification: Source coding is the method of converting a word to stream of bits that is 0’s and 1’s.
7. When the base of the logarithm is 2, then the unit of measure of information is
A. Bits
B. Bytes
C. Nats
D. None of the mentioned
Answer: A
Clarification: When the base of the logarithm is 2 then the unit of measure of information is bits.
8. When X and Y are statistically independent, then I (x,y) is
A. 1
B. 0
C. Ln 2
D. Cannot be determined
Answer: B
Clarification: When X and Y are statistically independent the measure of information I (x,y) is 0.
9. The self information of random variable is
A. 0
B. 1
C. Infinite
D. Cannot be determined
Answer: C
Clarification: The self information of a random variable is infinity.
10. Entropy of a random variable is
A. 0
B. 1
C. Infinite
D. Cannot be determined
Answer: C
Clarification: Entropy of a random variable is also infinity.
11. Which is more efficient method?
A. Encoding each symbol of a block
B. Encoding block of symbols
C. Encoding each symbol of a block & Encoding block of symbols
D. None of the mentioned
Answer: B
Clarification: Encoding block of symbols is more efficient than encoding each symbol of a block.
12. Lempel-Ziv algorithm is
A. Variable to fixed length algorithm
B. Fixed to variable length algorithm
C. Fixed to fixed length algorithm
D. Variable to variable length algorithm
Answer: A
Clarification: Lempel-Ziv algorithm is a variable to fixed length algorithm.
13. Coded system are inherently capable of better transmission efficiency than the uncoded system.
A. True
B. False
Answer: A
Clarification: Yes, the coded systems are capable of better transmission efficiency than the uncoded system.