UGC NET Computer Science Solved Paper -II June2013

Questions along with Answers Below - Explanations are always welcome

1. COCOMO stands for

(A) COmposite COst MOdel

(B) COnstructive COst MOdel

(C) COnstructive Composite MOdel

(D) COmprehensive Construction Model

2. Match the following:

a. Good quality     1. Program does not fail for a specified time in a given environment

b. Correctness     ii. Meets the functional requirements

c. Predictable      iii. Meets both functional and non-functional requirements

d. Reliable          iv. Process is under statistical control

Codes:

      a   b  c  d

(A) iii  ii   iv  i

(B) ii   iii  iv  i 

(C) i    ii  iv  iii

(D) i    ii  iii  iv

3. While estimating the cost of software, Lines of Code (LOC) and Function Points (FP) are used to measure which one of the following?

(A) Length of code

(B) Size of software

(C) Functionality of software

(D) None of the above

4. A good software design must have

(A) High module coupling, High module cohesion

(B) High module coupling, Low module cohesion

(C) Low module coupling, High module cohesion

(D) Low module coupling, Low module cohesion

5. Cyclometric complexity of a flow graph G with n vertices and e edges is

(A) V(G) = e+n-2

(B) V(G) = e-n+2

(C) V(G) = e+n+2

(D) V(G) = e-n-2

6. When the following code is executed what will be the value of x and y?

     int x = l, y=0;

          y = x++;

(A) 2,1

(B) 2,2

(C) 1,1

(D) 1,2

 

7. How many values can be held by an array A(-1,m;1 ,m) ?

(A) m

(B) m²

(C) m(m+l)

(D) m(m+2)

8. What is the result of the expression

(1 &2)+(3/4) ?

(A) 1

(B) 2

(C) 3

(D) 0

9. How many times the word 'print' shall be printed by the following program segment?

for(i=1, i≤2, i++)

for(j=1, J≤2, J++)

for(k=1, k≤2, k++)

printf("print/n")

(A) 1

(B) 3

(C) 6

(D) 8

10. Which of the following is not a type of Database Management System?

(A) Hierarchical

(B) Network

(C) Relational

(D) Sequential

11. Manager's salary details are to be hidden from Employee Table. This Technique is called as

(A) Conceptual level Datahiding

(B) Physical level Datahiding

(C) External level Datahiding

(D) Logical level Datahiding

12. A Network Schema

(A) restricts to one to many relationship

(B) permits many to many relationship

(C) stores Data in a Database

(D) stores Data in a Relation

13. Which normal form is considered as adequate for usual database design ?

(A) 2NF

(B) 3NF

(C) 4NF

(D) 5NF

14. If D₁, D₂,…. D_n are domains in a relational model, then the relation is a table, which is a subset of

(A) D₁+D₂+…. + D_n

(B) D₁x D₂x… x D_n

(C) D₁U D₂U….U D_n

(D) D₁- D₂-….- D_n

15. Which of the following addresses is used to deliver a message to the correct application program running on a host?

(A) Port

(B) IP

(C) Logical

(D) Physical

16. In substitution, a character in the plaintext is always changed to the same character in the ciphertext, regardless of its position in the text.

(A) polyalphabetic

(B) monoalphabetic

(C) transpositional

(D) multialphabetic

17. In classful addressing, the IF address 190.255.254.254 belongs to

(A) Class A

(B) Class B

(C) Class C

(D) Class D

18. In hierarchical routing with 4800 routers, what region and cluster sizes should be chosen to minimize the size of the routing table for a threelayer hierarchy?

(A) 10 clusters, 24 regions and 20 routers

(B) 12 clusters, 20 regions and 20 routers

(C) 16 clusters, 12 regions and 25 routers

(D) 15 clusters, 16 regions and 20 routers

19. In IPv4 header, the field is needed to allow the destination host to determine which datagram a newly arrived fragments belongs to.

(A) identification

(B) fragment offset

(C) time to live

(D) header checksum

20. Given L1 = L(a*baa*) and L2 = L(ab*)

The regular expression corresponding to language L3 = Ll/L2 (right quotient) is given by

(A) a*b

(B) a*baa*

(C) a*ba*

(D) None of the above

21. Given the production rules of a grammar GI as

S₁ à AB | aaB

A à a | Aa

B à b

and the production rules of a grammar G2 as

S₂ à aS₂bS₂ | bS₂aS₂ | λ

Which of the following IS correct statement?

(A) G1 is ambiguous and G2 is not ambiguous.

(B) GI is ambiguous and G2 is ambiguous.

(C) GI is not ambiguous and G2 is ambiguous.

(D) GI is not ambiguous and G2 is not ambiguous.

22. Given a grammar : S1 à Sc, S àSA | A, A à aSb | ab, there is a rightmost derivation

S1 => Sc => SAC => SaSbc Thus, SaSbc is a right sentential form, and its handle is

(A) SaS

(B) be

(C) Sbe

(D) aSb

23. The equivalent production rules corresponding to the production rules

      S à Sα₁ | Sα₂ | β₁ | β₂  is

(A) S à β₁ | β₂, A à α₁A | α₂A | λ

(B) S à β₁ | β₂ | β₁A | β₂A,

      Aà α₁A | α₂A

(C) Sàβ₁ | β₂, A à α₁A | α₂A

(D) S à β₁ | β₂ | β₁A | β₂A,

      A à α₁A | α₂A | λ

24. Given a Non-deterministic Finite Automation (NFA) with states p and r as initial and final states respectively transItion table as given below

	a	b
p	-	q
q	r	s
r	r	s
s	r	s

The minimum number of states required in Deterministic Finite Automation (DFA) equivalent to NFA is

(A) 5

(B) 4

(C) 3

(D) 2

25. Which is the correct statement(s) for Non Recursive predictive parser?

S1: First(α) = {t | α => * t β for some string β } => *tβ

S2: Follow(X) = { a | S => * αXa β for some strings α and β }

(A) Both statements S1 and S2 are incorrect.

(B) S1 is incorrect and 52 IS correct.

(C) S1 is correct and S2 IS incorrect.

(D) Both statements S I and S2 are correct. 

26. Given an open address hash table with load factor α < 1, the expected number of probes in a successful search is
(A) Atmost  1/α 1n (1-α/α)

(B) Atmost  1/α 1n (1/1-α)

(C) Atleast  1/α 1n (1/1-α)

(D) Atleast  1/α 1n (α/1-α)

27. For a B-tree of height h and degree t, the total CPU time used to insert a node is

(A) O(h log t)

(B) O(t log h)

(C) O(t_²h)

(D) O(th)

28. The time complexity to build a heap with a list of n numbers is

(A) O(log n)

(B) O(n)

(C) O(n log n)

(D) O(n²)

29. The value of postfix expression:

     8 3 4 + - 3 8 2 / + * 2 ^ 3 +  is

(A) 17

(B) 131

(C) 64

(D) 52

Note:  Given $ symbol instead of ^ in the question paper given by UGC

30. Consider the following statements for priority queue:

S1 : It is a data structure in which the intrinsic ordering of the elements does determine the result of its basic operations.

S2: The elements of a priority queue may be complex structures that are ordered on one or several fields.

Which of the following is correct?

(A) Both S1 and S2 are incorrect.

(B) S1 is correct and S2 is incorrect.

(C) SI is incorrect and S2 is correct.

(D) Both S1 and S2 are correct.

31. Repository of information gathered from multiple sources, storing under unified scheme at a single site is called as

(A) Data mining

(B) Meta data

(C) Data warehousing

(D) Database

32. The task of correcting and pre processing data is called as

(A) Data streaming

(B) Data cleaning

(C) Data mining

(D) Data storming

33. Using data p=3, q=11, n=pq, d=7  in RSA algorithm find the cipher text of the given plain text SUZANNE

(A) BUTAEEZ

(B) SUZANNE

(C) XYZABCD

(D) ABCDXYZ  
Explanation:   

-----------------------------------------------------------------------------------------------------------------------------------------------
Encryption RSA algorithm
Cipher text = ((plaintext)^e)mod n
From the given problem we know p =3,q = 11, d =7, n=33 find z :: z = ((p-1)*(q-1)) => 2*10 = 20
Find 'e' or 'd' using the given method : (de) mod z = 1
Therefore (7e)mod 20 = 1 => with trail and error giving e =3, => (7*3)mod 20 = 1
Finding e=3 we go to the encryption by converting the given plain text equivalent number starting a=1,b=2...z=26
Therefore SUZANNE = 19,21,26,1,14,14,5 taking single character and apply encryption
(19^3) mod 33 = 28 ie (28-26) = 2 => B
(21^3) mod 33 = 21 => U
(26^3)mod 33 = 20 => T
(1^3)mod 33 = 1 => A
(14^3)mod 33 = 5 =>E
(5^3)mod 33 = 26 => Z
-----------------------------------------------------------------------------------------------------------------------------------------------

35. Give as good a big-Q estimate as possible for the following functions:

(nlogn+n²)(n³+2) and (n!+2ⁿ) (n³+log(n²+ 1))

(A) O(n⁵+2n²) & O(n³*n!)

(B) O(n⁵) & O(n³*2 ⁿ)

(C) O(n⁵) & O(n³* n!)

(D) O(n⁵+2n²) & O(n³*2 ⁿ)

36. A test contains 100 true/false questions. How many different ways can a student answer the questions on the test, if the answer may be left blank also.

(A) ¹⁰⁰_P2    (B) ¹⁰⁰_C2     (C) 2¹⁰⁰     (D) 3¹⁰⁰ 

37. Which of the following connected simple graph has exactly one spanning tree?

(A) Complete graph

(B) Hamiltonian graph

(C) Euler graph

(D) None of the above

38. How many edges must be removed to produce the spanning forest of a graph with N vertices, M edges and C connected components?

(A) M+N-C

(B) M-N-C

(C) M-N+C

(D) M+N+C

39. Which of the following shall be a compound proposition involving the propositions p, q and r. that is true when exactly two of the p. q and rare true and is false otherwise?

(A) (p∨q∧˥r) ∨ (p∨q∧r)  ∧ (˥p∧q∨r)

(B) (p∧q∨r)   ∧ (p∧q∧r)  ∨ (˥q∨˥p∧˥r)

(C) (p∧q∧˥r) ∨ (p∨˥q∧r) ∨ (˥p∧q∧r)

(D) (p∨r∧q)  ∨ (p∧q∧r)   ∨ (˥p∧q∧r) 

40. The truth value of the statements:

∃!xP(x) à ∃xP(x) and ∃!x˥P(x) à ˥∀xP(x), (where the notation ∃!xP(x) denotes the proposition "There exists a unique x such that P(x) is true'') are :

(A) True and False

(B) False and True

(C) False and False

(D) True and True

41. How many different Boolean functions of degree 4 are there?

(A) 2⁴

(B) 2⁸

(C) 2¹²

(D) 2¹⁶

42. A Boolean operator Ө  is defined as follows:

1 Ө 1 =1, 1 Ө 0 = 0, 0 Ө 1= 0 and 0 Ө 0 =1

What will be the truth value of the expression (x Ө y) Ө z = x Ө (y Ө z)?

(A) Always false

(B) Always true

(C) Sometimes true
(D) True when x,y,z are all true

43. Which one of the following is decimal value of a signed binary number 1101010, if it is in 2's complement form ?

(A) -42

(B) - 22

(C) - 21

(D) -106

44. A set of processors P1, P2, ......, Pk can execute in parallel if Bernstein's conditions are satisfied on a pairwise basis; that is

      P1 || P2 || P3 || ..... || Pk if and only if:

(A) Pi || Pj for all i ≠ j

(B) Pi || Pj for all i = j+1

(C) Pi || Pj for all i ≤ j

(D) Pi || Pj for all i ≥ j

45. When a mobile telephone physically moves from one to another cell, the base station transfers ownership to the cell getting strongest signal. This process is known as _______

(A) handoff

(B) mobile switching

(C) mobile routing

(D) cell switching

46. A virtual memory based memory management algorithm partially swaps out a process. This is an example of

(A) short term scheduling

(B) long term scheduling

(C) medium term scheduling

(D) mutual exclusion

47. Assuming that the disk head IS located initially at 32, find the number of disk moves required with FCFS if the disk queue of I/O block requests are 98, 37, 14, 124,65,67 :

(A) 310

(B) 324

(C) 320

(D) 321

48. Let the page fault service time be 10 millisecond(ms) in a computer with average memory access time being 20 nanosecond(ns). If one page fault is generated for every 10⁶ memory accesses, what is the effective access time for memory ?

(A) 21 ns

(B) 23 ns

(C) 30 ns

(D) 35 ns

49. Consider the following UNIX command:

sort <in> temp; head -30 <temp; rm temp

Which of the following functions shall be performed by this command?

(A) Sort, taking the input from "temp", prints 30 lines from temp and delete the file temp

(B) Sort the file "temp", removes 30 lines from temp and delete the file temp

(C) Sort, taking the input from "in" and writing the output to "temp" then prints 30 lines from temp on terminal. Finally "temp" is removed.

(D) Sort, taking the input from "temp" and then prints 30 lines from "temp" on terminal. Finally "temp" is removed.

50. The mv command changes

(A) the inode

(B) the inode-number

(C) the directory entry

(D) both the directory entry and the inode