UGC NET CS 2018 Dec – II

Question 31

Consider the following pseudo-code fragment, where m is a non-negative integer that has been initialized :

p=0;
k=0;
while(k < m)
        p = p + 2k;
        k=k+1;
end while 

Which of the following is a loop invariant for the while statement? (Note: a loop variant for a while statement is an assertion that is true each time guard is evaluated during the execution of the while statement).

• p = 2^k − 1 and 0≤k<m
• p = 2^k+1 − 1 and 0≤k<m
• p = 2^k − 1 and 0≤k≤m
• p = 2^k+1 − 1 and 0≤k≤m

Question 32

The K-coloring of an undirected graph G=(V,E) is a function C: V➝{0,1,......,K-1} such that c(u)≠c(v) for every edge (u,v) ∈ E Which of the following is not correct ?

• G has no cycles of odd length
• G has cycle of odd length
• G is 2-colorable
• G is bipartite

Question 33

Consider the following problems:

• (i) Whether a finite automaton halts on all inputs?
• (ii) Whether a given Context Free Language is Regular?
• (iii) Whether a Turing Machine computes the product of two numbers?

Which one of the following is correct ?

• Only (ii) and (iii) are undecidable problems
• (i), (ii) and (iii) are undecidable problems
• Only (i) and (ii) are undecidable problems
• Only (i) and (iii) are undecidable problems

Question 34

Consider the following statements

• S1:​ A heuristic is admissible if it never overestimates the cost to reach the goal.
• S2:​ A heuristic is monotonous if it follows triangle inequality property.

Which one of the following is true referencing the above statements ?

• Statement S1 is true but statement S2 is false.
• Statement S1 is false but statement S2 is true.
• Neither of the statements S1 and S2 are true.
• Both the statements S1 and S2 are true.

Question 35

Consider the following two statements:

• S1: TCP handles both congestion and flow control.
• S2: UDP handles congestion but not flow control.

Which of the following option is correct with respect to the above statements (S1) and (S2) ?

• Both S1 and S2 are correct
• Neither S1 nor S2 is correct
• S1 is not correct but S2 is correct
• S1 is correct but S2 is not correct

Question 36

Match the following secret key algorithm (List 1) with the corresponding key lengths (List 2) and choose the correct answer from the code given below.

• (a)-(ii),(b)-(iii), (c)- (iv), (d)-(i)
• (a)-(iv),(b)-(iii), (c)- (ii), (d)-(i)
• (a)-(iii),(b)-(iv), (c)- (ii), (d)-(i)
• (a)-(iii),(b)-(iv), (c)- (i), (d)-(ii)

Question 37

The boolean expression A’⋅B+A.B’+A.B is equivalent to

• A+B
• A.B
• (A+B)’
• A’.B

Question 38

​If a graph (G) has no loops or parallel edges and if the number of vertices(n) in the graph is n≥3, then the graph G is Hamiltonian if

(i) deg(v) ≥n/3 for each vertex v
(ii) deg(v) + deg(w) ≥ n whenever v and w are not connected by an edge.
(iii) E (G) ≥ 1/3 (n − 1 )(n − 2 ) + 2 

• (i) and (iii) only
• (ii) and (iii) only
• (iii) only
• (ii) only

Question 39

Consider a disk pack with 32 surfaces, 64 tracks and 512 sectors per pack. 256 bytes of data are stored in a bit serial manner in a sector. The number of bits required to specify a particular sector in the disk is

• 19
• 20
• 18
• 22

Question 40

Match each UML diagram in List 1 with Appropriate description in List 2

• (a)-(i), (b)-(iv), (c) -(iii), (d)-(ii)
• (a)-(iv), (b)-(ii), (c) -(i), (d)-(iii)
• (a)-(iv), (b)-(i), (c) -(ii), (d)-(iii)
• (a)-(i), (b)-(iv), (c) -(ii), (d)-(iii)