Tuesday, 3 October 2017

UGC Net Computer Science December 13 Paper 3 Page 4 Solved

UGC Net Computer Science December 13 Paper 3 Page 4 Solved

31. Consider the formula in image

CR is called as compression ratio n1 and n2 denotes the number of information carrying units in two
datasets that represent the same information. In this situation RD is called as relative _________ of the
first data set.
(A) Data Compression
(B) Data Redundancy
(C) Data Relation
(D) Data Representation

32. Find the false statement :
(A) In Modern Cryptography, symmetric key algorithms use same key both for Encryption and Decryption.
(B) The symmetric cipher DES (Data Encryption Standard) was widely used in the industry for security product.
(C) The AES (Advanced Encryption Standard) cryptosystem allows variable key lengths of size 56 bits and 124 bits.
(D) Public key algorithms use two different keys for Encryption and Decryption.

33.The message 11001001 is to be transmitted using the CRC polynomial x3 + 1 to protect it from
errors. The message that should be transmitted is
(A) 110010011001
(B) 11001001
(C) 110010011001001
(D) 11001001011

34. _________ comparisons are necessary in the worst case to find both the maximum and minimum of n numbers.
(A) 2n – 2
(B) n + floor (lg n) – 2

(D) 2 lg n – 2

35. Let A and B be two n × n matrices. The efficient algorithm to multiply the two matrices has the time complexity

36. The recurrence relation T(n)= Tan2  is satisfied by

37.The longest common subsequence of the sequences X = <A, B, C, B, D, A, B> and Y = <B, D, C, A, B, A> has length
(A) 2 
(B) 3
(C) 4 
(D) 5

38.Assuming there are n keys and each key is in the range [0, m – 1].The run time of bucket sort is
(A) O(n) 
(B) O(n lgn)
(C) O(n lgm) 
(D) O(n + m)

39. A _________ complete subgraph and a _________ subset of vertices of a graph G = (V, E) are a clique and a vertex cover respectively.
(A) minimal, maximal
(B) minimal, minimal
(C) maximal, maximal
(D) maximal, minimal

40. Pumping lemma for context-free languages states : Let L be an infinite context free language. Then there exists some positive integer m such that any w ∈ L with |w| ≥ m can be decomposed as
w = uv xy Z with |vxy| _________ and |vy| _________ such that uv .z xy .z Z ∈ L for all .z = 0, 1, 2, ....... .
(A) ≤ m, ≤ 1 (B) ≤ m, ≥ 1
(C) ≥ m, ≤ 1 (D) ≥ m, ≥ 1