Data compression unit 2 mcq

1. Huffman codes are ______ codes and are optimum for a given model (set of probabilities).
(A) Parity
(B) Prefix
(C) Convolutional code
(D) Block code

Correct option is B

2. The Huffman procedure is based on observations regarding optimum prefix codes, which is/are
(A) In an optimum code, symbols that occur more frequently (have a higher probability of occurrence) will have shorter codewords than symbols that occur less frequently.
(B) In an optimum code,thetwo symbolsthat occurleast frequently will havethe samelength
(C) Both (A) and (B)
(D) None of these

Correct option is C

3. The best algorithms for solving Huffman codes
(A) Brute force algorithm
(B) Divide and conquer algorithm
(C) Greedy algorithm
(D) Exhaustive search

4. How many printable characters does the ASCII character set consists of?

(A) 128
(B) 100
(C) 95
(D) 90

Correct option is C

5. The difference between the entropy and the average length of the Huffman code is called
(A) Rate
(B) Redundancy
(C) Power
(D) None of these

Correct option is B

6. Unit of redundancy is
(A) bits/second
(B) symbol/bits
(C) bits/symbol
(D) none of these

Correct option is C

7. The redundancy is zero when
(A) The probabilities are positive powers of two
(B) The probabilities are negative powers of two
(C) Both
(D) None of the above

Correct option is B

8. Which bit is reserved as a parity bit in an ASCII set?
(A) 6
(B) 5
(C) 8
(D) 7

Correct option is C

9. Bits are needed for standard encoding if the size of the character set is X
(A) X+1
(B) log(X)
(C) X²
(D) 2X

Correct option is B

10. In Huffman coding, data in a tree always occur in
(A) Leaves
(B) Roots
(C) Left sub trees
(D) None of these

Correct option is A

11. An optimal code will always be present in a full tree.
(A) True
(B) False

Correct option is A

12. Running time of the Huffman encoding algorithm is
(A) O(Nlog(C))
(B) O(Clog(C))
(C) O(C)
(D) O(log(C))

Correct option is B

13. Running time of the Huffman algorithm if its implementation of the priority queue is done using linked lists
(A) O(log(C))
(B) O(Clog(C))
(C) O(C²)
(D) O(C)

Correct option is C

14. The unary code for a positive integer n is simply n ___ followed by a ___.
(A) zero, ones
(B) ones, zero
(C) None of these

Correct option is B

15. The unary code for 4 is ______.
(A) 11100
(B) 11110
(C) 00001
(D) 00011

Correct option is B

16. In the Tunstall code, all codewords are of _____ length. However, each codeword represents a _________ number of letters.
(A) different, equal
(B) equal, different
(C) none of these

Correct option is B

17. Tunstall coding is a form of entropy coding used for
(A) Lossless data compression
(B) Lossy data compression
(C) Both
(D) None of these

Correct option is A

18. The main advantage of a Tunstall code is that
(A) Errors in codewords do not propagate
(B) Errors in codewords propagate
(C) The disparity between frequencies
(D) None of these

Correct option is A

19. Applications of Huffman Coding
(A) Text compression
(B) Audio compression
(C) Lossless image compression
(D) All of the above

Correct option is D