# UGC NET SOLVED PAPER

## UGC NET Computer Science Solved Paper II - June 2015

1.       How many strings of 5 digits have the property that the sum of their digits is 7 ?
(A) 66     (B) 330
(C) 495  (D) 99
Answer: B
2.       Consider an experiment of tossing two fair dice, one black and one red. What is the probability that the number on the black die divides the number on red die ?
(A) 22 / 36         (B) 12 / 36
(C) 14 / 36         (D) 6 / 36
Answer: C
3.       In how many ways can 15 indistinguishable fish be placed into 5 different ponds, so that each pond contains at least one fish ?
(A) 1001                        (B) 3876
(C) 775              (D) 200
Answer: A
4.       Consider the following statements:
(a) Depth - first search is used to traverse a rooted tree.
(b) Pre - order, Post-order and Inorder are used to list the vertices of an ordered rooted tree.
(c) Huffman's algorithm is used to find an optimal binary tree with given weights.
(d) Topological sorting provides a labelling such that the parents have larger labels than their children.
Which of the above statements are true ?
(A) (a) and (b)               (B) (c) and (d)
(C) (a) , (b) and (c)       (D) (a), (b) , (c) and (d)
Answer: D
5.       Consider a Hamiltonian Graph (G) with no loops and parallel edges. Which of the following is true with respect to this Graph (G) ?
(a) deg(v) ≥ n/2 for each vertex of G
(b) |E(G)| ≥ 1/2 (n-1)(n-2)+2 edges
(c) deg(v) + deg(w) ≥ n for every v and w not connected by an edge
(A) (a) and (b)               (B) (b) and (c)
(C) (a) and (c)               (D) (a), (b) and (c)
Answer: D

6.       Consider the following statements :
(a) Boolean expressions and logic networks correspond to labelled acyclic digraphs.
(b) Optimal Boolean expressions may not correspond to simplest networks.
(c) Choosing essential blocks first in a Karnaugh map and then greedily choosing the largest remaining blocks to cover may not give an optimal expression.
Which of these statement(s) is/ are correct?
(A) (a) only                    (B) (b) only
(C) (a) and (b)               (D) (a), (b) and (c)
Answer: D
7.       Consider a full-adder with the following input values:
(a) x=1, y=0 and Ci(carry input) = 0
(b) x=0, y=1 and Ci = 1
Compute the values of S(sum) and C0 (carry output) for the above input values.
(A) S=1 , C0= 0 and S=0 , C0= 1        (B) S=0 , C0= 0 and S=1 , C0​= 1
(C) S=1 , C0= 1 and S=0 , C0​= 0        (D) S=0 , C0= 1 and S=1 , C0​= 0
Answer: A
8.       "lf my computations are correct and I pay the electric bill, then I will run out of money. If I don't pay the electric bill, the power will be turned off. Therefore, if I don't run out of money and the power is still on, then my computations are incorrect."
Convert this argument into logical notations using the variables c, b, r, p for propositions of computations, electric bills, out of money and the power respectively. (Where  ¬ means NOT)
(A) if (cb) → r and ¬b → ¬p, then (¬rp)→¬c
(B) if (cb) → r and ¬b → ¬p, then (rp)→c
(C) if (cb) → r and ¬p → ¬b, then (¬rp)→¬c
(D) if (cb) → r and ¬b → ¬p, then (¬rp)→¬c
Answer: A
9.       Match the following:
List - I                                     List - II
(a) (p →q)  (¬q→¬p)            (i) Contrapositive
(b) [(pq)→r][p→ (q→r)]      (ii) Exportation law
(c) (p→q)[(p¬q)→o]           (iii) Reductio ad absurdum
(d) (pq)[(p→q)(q→p)]    (iv) Equivalence
Codes:
(a)    (b)   (c)   (d)
(A) (i)     (ii)    (iii)  (iv)
(B) (ii)    (iii)   (i)    (iv)
(C) (iii)   (ii)    (iv)   (i)
(D) (iv)   (ii)    (iii)   (i)
Answer: A
10.    Consider a proposition given as:
"x≥6, if x2≥25 and its proof as:
If x≥6, then x2=x.x=6.6=36≥25
Which of the following is correct w.r.to the given proposition and its proof ?
(a) The proof shows the converse of what is to be proved.
(b) The proof starts by assuming what is to be shown.
(c) The proof is correct and there is nothing wrong.
(A) (a) only        (B) (c) only
(C) (a) and (b)   (D) (b) only
Answer: C

11.       What is the output of the following program ?
(Assume that the appropriate pre-processor directives are included and there is no syntax error)
main()
{
char S[ ] = "ABCDEFGH";
printf ("%C",* (& S));
printf ("%s", S+4);
printf ("%u", S);
/* Base address of S is 1000 */             }
(A) ABCDEFGH1000              (B) CDEFGH1000
(C) DDEFGHH1000                (D) DEFGH1000
Answer: D
12.       Which of the following, in C++, is inherited in a derived class from base class ?
(A) constructor             (B) destructor
(C) data members        (D) virtual methods
Answer: C
13.       Given that x=7.5, j=-1.0, n=1.0, m=2.0
the value of --x+j == x>n>=m is:
(A) 0       (B) 1
(C) 2       (D) 3
Answer: A
14.       Which of the following is incorrect in C++ ?
(A) When we write overloaded function we must code the function for each usage.
(B) When we write function template we code the function only once.
(C) It is difficult to debug macros
(D) Templates are more efficient than macros
Answer: D
15.       When the inheritance is private, the private methods in base class are.................. in the derived class (in C++).
(A) inaccessible           (B) accessible
(C) protected                 (D) public
Answer: A

16.       An Assertion is a predicate expressing a condition we wish database to always satisfy. The correct syntax for Assertion is :
(A) CREATE ASSERTION ‘ASSERTION Name’ CHECK ‘Predicate’
(B) CREATE ASSERTION ‘ASSERTION NAME’
(C) CREATE ASSERTION, CHECK Predicate
(D) SELECT ASSERTION
Answer: A
17.       Which of the following concurrency protocol ensures both conflict serializability and freedom from deadlock ?
(a) 2-phase Locking
(b) Time stamp - ordering
(A) Both (a) and (b)     (B) (a) only
(C) (b) only                    (D) Neither (a) nor (b)
Answer: C
18.       Drop Table cannot be used to drop a Table referenced by .................. constraint.
(a) Primary key             (b) Sub key    (c) Super key            (d) Foreign key
(A) (a)                 (B) (a), (b) and (c)
(C) (d)                (D) (a) and (d)
Answer: C
19.       Database applications were built directly on top of file system to overcome the following drawbacks of using file-systems
(a) Data redundancy and inconsistency
(b) Difficulty in accessing Data
(c) Data isolation
(d) Integrity problems
(A) (a)                             (B) (a) and (d)
(C) (a), (b) and (c)        (D) (a), (b), (c) and (d)
Answer: D
20.    For a weak entity set to be meaningful, it must be associated with another entity set in combination with some of their attribute values, is called as :
(A) Neighbour Set       (B) Strong Entity Set
(C) Owner entity set    (D) Weak Set
Answer: C

21.       Consider the given graph:
Its Minimum Cost Spanning Tree is ..................
Answer: B
22.       The inorder and preorder Traversal of binary Tree are dbeafcg and abdecfg respectively. The post-order Traversal is ............
(A) dbefacg                   (B) debfagc
(C) dbefcga                   (D) debfgca
Answer: D
23.       Level order Traversal of a rooted Tree can be done by starting from root and performing:
(A) Breadth First Search        (B) Depth first search
(C) Root search                       (D) Deep search
Answer: A
24.       The average case occurs in the Linear Search Algorithm when:
(A) The item to be searched is in some where middle of the Array
(B) The item to be searched is not in the array
(C) The item to be searched is in the last of the array
(D) The item to be searched is either in the last or not in the array
Answer: A
25.       To determine the efficiency of an algorithm the time factor is measured by:
(A) Counting micro seconds
(B) Counting number of key operations
(C) Counting number of statements
(D) Counting kilobytes of algorithm
Answer: B

26.       Which of the following protocols is an application layer protocol that establishes, manages and terminates multimedia sessions?
(A) Session Maintenance Protocol
(B) Real - time Streaming Protocol
(C) Real - time Transport Control Protocol
(D) Session Initiation Protocol
Answer: D
27.       Match the following port numbers with their uses:
List – I                                    List – II
(a) 23                             (i) World wide web
(b) 25                             (ii) Remote Login
(c) 80                              (iii) USENET news
(d) 119                           (iv) E-mail
(a)   (b)   (c)   (d)
(A) (iv)   (i)    (ii)   (iii)
(B) (ii)    (i)    (iv)  (iii)
(C) (ii)    (iv)  (iii)  (i)
(D) (ii)    (iv)  (i)    (iii)
Answer: D
28.       Which of the following is not associated with the session layer ?
(A) Dialog control
(B) Token management
(C) Semantics of the information transmitted
(D) Synchronization
Answer: C
29.       What is the size of the 'total length' field in IPv 4 datagram ?
(A) 4 bits            (B) 8 bits
(C) 16 bits         (D) 32 bits
Answer: C
30.    Which of the following is/are restriction(s) in classless addressing ?
(A) The number of addresses needs to be a power of 2.
(B) The mask needs to be included in the address to define the block.
(C) The starting address must be divisible by the number of addresses in the block.
(D) All of the above
Answer: D

31.       Match the following:
List – I                                                List – II
(a) Forward Reference Table                        (i) Assembler directive
(b) Mnemonic Table                            (ii) Uses array data structure
(c) Segment Register Table               (iii) Contains machine OP code
(d) EQU                                                 (iv) Uses linked list data structure
Codes:
(a)    (b)   (c)   (d)
(A) (ii)    (iii)   (iv)  (i)
(B) (iii)   (iv)   (ii)   (i)
(C) (iv)   (i)    (iii)   (ii)
(D) (iv)   (iii)   (ii)   (i)
Answer: D
32.       The translator which performs macro calls expansion is called :
(A) Macro processor                (B) Micro pre-processor
(C) Macro pre-processor         (D) Dynamic linker
Answer: C
33.       If all the production rules have single non - terminal symbol on the left side, the grammar defined is :
(A) context free grammar                    (B) context sensitive grammar
(C) unrestricted grammar                   (D) phrase grammar
Answer: A
34.       Which one from the following is false ?
(A) LALR parser is Bottom - Up parser
(B) A parsing algorithm which performs a left to right scanning and a right most deviation is RL (1).
(C) LR parser is Bottom - Up parser.
(D) In LL(1), the 1 indicates that there is a one - symbol look - ahead.
Answer: B
35.       Which phase of compiler generates stream of atoms ?
(A) Syntax analysis     (B) Lexical Analysis
(C) Code generation   (D) Code optimization
Answer: A

36.       A disk drive has 100 cylinders, numbered 0 to 99. Disk requests come to the disk driver for cyclinders 12, 26, 24, 4, 42, 8 and 50 in that order. The driver is currently serving a request at cyclinder 24. A seek takes 6 msec per cyclinder moved. How much seek time is needed for shortest seek time first (SSTF) algorithm?
(A) 0.984 sec                (B) 0.396 sec
(C) 0.738 sec                (D) 0.42 sec
Answer: D
37.       Let Pi and Pj be two processes, R be the set of variables read from memory, and W be the set of variables written to memory. For the concurrent execution of two processes Pi and Pj, which of the following conditions is not true?
(A) R(Pi)∩W(Pj)=Φ       (B) W(Pi)∩R(Pj)=Φ
(C) R(Pi)∩R(Pj)=Φ       (D) W(Pi)∩W(Pj)=Φ
Answer: C
38.       A LRU page replacement is used with four page frames and eight pages. How many page faults will occur with the reference string 0172327103 if the four frames are initially empty?
(A) 6                   (B) 7
(C) 5                   (D) 8
Answer: B
39.       What does the following command do?
grep −vn “abc” x
(A) It will print all of the lines in the file x that match the search string “abc”
(B) It will print all of the lines in file x that do not match the search string “abc”
(C) It will print total number of lines in the file x that match the search string “abc”
(D) It will print the specific line numbers of the file x in which there is a match for string “abc”
Answer: A
40.    The Unix Kernel maintains two key data structures related to processes, the process table and the user structure. Which of following information is not the part of user structure?
(A) File descriptor table          (B) System call state
(C) Scheduling parameters   (D) Kernel stack
Answer: C

41.       Match the following:
List – I                                                List – II
(a) Size-oriented metrics                    (i) uses number of external interfaces
as one of the measurement parameter.
(b) Function-oriented metrics                        (ii) originally designed to be applied to
business information systems.
(c) Extended Function Point Metrics           (iii) derived by normalizing quality and/or
productivity measures by considering
the size of the software.
(d) Function point                                (iv) uses algorithm characteristics
as of the measurement parameter.
Codes:
(a)   (b)   (c)   (d)
(A) (iii)   (iv)  (i)    (ii)
(B) (ii)    (i)   (iv)   (iii)
(C) (iv)   (ii)  (iii)   (i)
(D) (iii)   (i)   (iv)   (ii)
Answer: D
42.       In which testing strategy requirements established during requirements analysis are validated against developed software?
(A) Validation testing              (B) Integration testing
(C) Regression testing           (D) System testing
Answer: A
43.       Which process model is also called as classic life cycle model?
(A) Waterfall model                 (B) RAD model
(C) Prototyping model             (D) Incremental model
Answer: A
44.       Cohesion is an extension of:
(A) Abstraction concept                      (B) Refinement concept
(C) Information hiding concept         (D) Modularity
Answer: C
45.       Which one from the following is highly associated activity of project planning?
(A) Keep track of the project progress.
(B) Compare actual and planned progress and costs
(C) Identify the activities, milestones and deliverables produced by a project
(D) Both (B) and (C)
Answer: C

46.       In the case of parallelization, Amdahl's law states that if P is the proportion of a program that can be made parallel and (1-P) is the proportion that cannot be parallelized, then the maximum speed-up that can be achieved by using N processors is:
(A) 1/((1-P)+N.P)
(B) 1/((N-1)P+P)
(C) 1/((1-P)+P/N)
(D) 1/(P+(1-P)/N)
Answer: C
47.       Which of the following statements is incorrect for Parallel Virtual Machine (PVM)?
(A) The PVM Communication model provides asynchronous blocking send, asynchronous blocking receive and non-blocking receive function.
(B) Message buffers are allocated dynamically.
(C) The PVM communication model assumes that any task can send a message to any other PVM task and that there is no limit to the size or number of such messages.
(D) In PVM Model, the message order is not preserved.
Answer: D
48.       Which of the following algorithms sort n integers, having the range 0 to (n2-1), in ascending order in O(n) time ?
(A) Selection sort         (B) Bubble sort
(C) Radix sort               (D) Insertion sort
Answer: C
49.       Which of the following statements is FALSE about weak entity set ?
(A) Weak entities can be deleted automatically when their strong entity is deleted.
(B) Weak entity set avoids the data duplication and consequent possible inconsistencies caused by duplicating the key of the strong entity.
(C) A weak entity set has no primary keys unless attributes of the strong entity set on which it depends are included.
(D) Tuples in a weak entity set are not partitioned according to their relationship with tuples in a strong entity set.
Answer: D
50.    Which of the following is not valid with reference to Message Passing Interface (MPI)?
(A) MPI can run on any hardware platform
(B) The programming model is a distributed memory model.
(C) All parallelism is implicit.
(D) MPI - Comm - Size returns the total number of MPI processes in specified communication.
Answer: C