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Monday 31 July 2017

UGC NET COMPUTER SCIENCE SOLVED QUESTION PAPER - 2 - JULY 2016

1.         How many different equivalence relations with exactly three different equivalence classes are there on a set with five element... thumbnail 1 summary

1.       How many different equivalence relations with exactly three different equivalence classes are there on a set with five elements?
(A) 10     (B) 15
(C) 25     (D) 30
Answer: C
2.       The number of different spanning trees in complete graph, K4 and bipartite graph K2,2 have .......... and .....…. respectively.
(A) 14, 14          (B) 16, 14
(C) 16, 4                        (D) 14, 4
Answer: C
3.       Suppose that R1 and R2 are reflexive relations on a set A.
Which of the following statements is correct?
(A) R1∩R2 is reflexive and R1UR2 is irreflexive.
(B) R1∩R2 is irreflexive and R1UR2 is reflexive.
(C) Both R1∩R2 and R1UR2 are reflexive.
(D) Both R1∩R2 and R1UR2 are irreflexive.
Answer: C
4.       There are three cards in a box. Both sides of one card are black, both sides of one card are red, and the third card has one black side and one red side. We pick a card at random and observe only one side.
What is the probability that the opposite side is the same colour as the one side we observed?
(A) 3/4                (B) 2/3
(C) 1/2                (D) 1/3
Answer: B
5.       A clique in a simple undirected graph is a complete subgraph that is not contained in any larger complete subgraph. How many cliques are there in the graph shown below?
(A) 2       (B) 4
(C) 5       (D) 6
Answer: C


6.       Which of the following logic expressions is incorrect?
(A) 1 ⊕ 0 = 1                (B) 1 ⊕ ⊕ 1 = 1
(C) 1 ⊕ ⊕ 0 = 1        (D) 1 ⊕ 1 = 1
Answer: C
7.       The IEEE-754 double-precision format to represent floating point numbers, has a length of ........... bits.
(A) 16                 (B) 32
(C) 48                 (D) 64
Answer: D
8.       Simplified Boolean equation for the following truth table is:

X
Y
Z
F
0
0
0
0
0
0
1
1
0
1
0
0
0
1
1
1
1
0
0
1
1
0
1
0
1
1
0
1
1
1
1
0
(A) F = yz’ + y’z            (B) F = xy’ + x’y
(C) F = x’z + xz’            (D) F = x’z + xz’ + xyz
Answer: C
9.       The simplified form of a Boolean equation (AB’+AB’C+AC)(A’C’+B’) is :
(A) AB’               (B) AB’C
(C) A’B               (D) ABC
Answer: A
10.    In a positive-edge-triggered JK flip-flop, if J and K both are high then the output will be ............. on the rising edge of the clock.
(A) No change             (B) Set
(C) Reset                       (D) Toggle
Answer: D


11.       Given i=0, j=1, k=-1
x=0.5, y=0.0
What is the output of the following expression in C language?
x * y < i + j || k
(A) -1      (B) 0
(C) 1       (D) 2
Answer: C
12.       The following statement in ‘C’
int(*f())[];
declares
(A) a function returning a pointer to an array of integers.
(B) a function returning an array of pointers to integers.
(C) array of functions returning pointers to integers.
(D) an illegal statement.
Answer: A
13.       Which one of the following is correct, when a class grants friend status to another class?
(A) The member functions of the class generating friendship can access the members of the friend class.
(B) All member functions of the class granted friendship have unrestricted access to the members of the class granting the friendship.
(C) Class friendship is reciprocal to each other
(D) There is no such concept.
Answer: B
14.       When a method in a subclass has the same name and type signatures as a method in the superclass, then the method in the subclass .................. the method in the superclass.
(A) Overloads               (B) Friendships
(C) Inherits                    (D) Overrides
Answer: D
15.       What is the value returned by the function f given below when n = 100 ?
int f(int n)
    { if (n==0) then return n;
    else
    return n + f(n-2);
    }
(A) 2550                        (B) 2556
(C) 5220                        (D) 5520
Answer: A


16.       In RDBMS, the constraint that no key attribute (column) may be NULL is referred to as:
(A) Referential integrity          (B) Multi-valued dependency
(C) Entity Integrity                    (D) Functional dependency
Answer: C
17.       Which of the following statement(s) is/are FALSE in the context of Relational DBMS ?
I. Views in a database system are important because they help with access control by allowing users to see only a particular subset of the data in the database.
II. E-R diagrams are useful to logically model concepts.
III. An update anomaly is when it is not possible to store information unless some other, unrelated information is stored as well.
IV. SQL is a procedural language.
(A) I and IV only           (B) III and IV only
(C) I, II and III only       (D) II, III and IV only
Answer: D
18.       In a relational database model, NULL values can be used for all but which one of the following?
(A) To allow duplicate tuples in the table by filling the primary key column(s) with NULL.
(B) To avoid confusion with actual legitimate data values like 0 (zero) for integer columns and ‘’ (the empty string) for string columns.
(C) To leave columns in a tuple marked as “unknown” when the actual value is unknown.
(D) To fill a column in a tuple when that column does not really “exist” for that particular tuple.
Answer: A
19.       Consider the following two commands C1 and C2 on the relation R from an SQL database:
C1: drop table R;
C2: delete from R;
Which of the following statements is TRUE?
I. Both C1 and C2 delete the schema for R.
II. C2 retains relation R, but deletes all tuples in R.
III. C1 deletes not only all tuples of R, but also the schema for R.
(A) I only                        (B) I and II only
(C) II and III only          (D) I, II and III
Answer: C
20.    Consider the following database table having A, B, C and D as its four attributes and four possible candidate keys (I, II, III and IV) for this table:
A
B
C
D
a1
b1
c1
d1
a2
b3
c3
d1
a1
b2
c1
d2
I: {B}       II: {B, C}          III: {A, D}         IV: {C, D}
If different symbols stand for different values in the table (e.g., d1 is definitely not equal to d2), then which of the above could not be the candidate key for the database table?
(A) I and III only            (B) III and IV only
(C) II only                      (D) I only
Answer: C


21.       Consider the following binary search tree:
If we remove the root node, which of the node from the left subtree will be the new root?
(A) 11                 (B) 12
(C) 13                 (D) 16
Answer: D
22.       Consider the following operations performed on a stack of size 5:
Push(a); Pop(); Push(b); Push(c); Pop();
Push(d); Pop(); Pop(); Push(e);
Which of the following statements is correct?
(A) Underflow occurs 
(B) Stack operations are performed smoothly
(C) Overflow occurs
(D) None of the above
Answer: B
23.       Suppose you are given a binary tree with n nodes, such that each node has exactly either zero or two children. The maximum height of the tree will be
(A) n/2 - 1                      (B) n/2 + 1
(C) (n-1)/2                     (D) (n+1)/2
Answer: C
24.       Which of the following is not an inherent application of stack?
(A) Implementation of Stack  (B) Evaluation of a postfix expression
(C) Job Scheduling                 (D) Reverse a string
Answer: C
25.       In how many ways can the string
A ∩ B - A ∩ B - A
be fully parenthesized to yield an infix expression?
(A) 15                 (B) 14
(C) 13                 (D) 12
Answer: B


26.       A multiplexer combines four 100-Kbps channels using a time slot of 2 bits. What is the bit rate?
(A) 100 Kbps                (B) 200 Kbps
(C) 400 kbps                 (D) 1000 Kbps
Answer: C
27.       In a fully-connected mesh network with 10 computers, total .............. number of cables are required and ................ number of ports are required for each device.
(A) 40, 9             (B) 45, 10
(C) 45, 9                        (D) 50, 10
Answer: C
28.       In TCP/IP Reference model, the job of ............... layer is to permit hosts to inject packets into any network and travel them independently to the destination.
(A) Physical                  (B) Transport
(C) Application             (D) Host-to-network
Answer: Marks to all
29.       If there are N people in the world and are using secret key encryption/decryption for privacy purpose, then number of secret keys required will be:
(A) N                  (B) (N-1)
(C) N(N-1)/2      (D) N(N+1)/2
Answer: C
30.    Optical fiber uses reflection to guide light through a channel, in which angle of incidence is ................. the critical angle.
(A) equal to                   (B) less than
(C) greater than           (D) less than or equal to
Answer: C


31.       The number of strings of length 4 that are generated by the regular expression (0|) 1+2* (3|), where | is an alternation character, {+, *} are quantification characters, and  is the null string, is:
(A) 08                 (B) 10
(C) 11                 (D) 12
Answer: D
32.       The content of the accumulator after the execution of the following 8085 assembly language program, is:
MVI A, 42H
MVI B, 05H
UGC:      ADD B
DCR B
JNZ UGC
ADI 25H
HLT
(A) 82 H             (B) 78 H
(C) 76 H             (D) 47 H
Answer: C
33.       In .............., the bodies of the two loops are merged together to form a single loop provided that they do not make any references to each other.
(A) Loop unrolling                   (B) Strength reduction
(C) Loop concatenation         (D) Loop jamming
Answer: D
34.       Which of the following is not typically a benefit of dynamic linking?
I. Reduction in overall program execution time.
II. Reduction in overall space consumption in memory.
III. Reduction in overall space consumption on disk.
IV. Reduction in the cost of software updates.
(A) I and IV                    (B) I only
(C) II and III                   (D) IV only
Answer: B
35.       Which of the following is FALSE ?
(A) The grammar S  aSb|bSa|SS|, where S is the only non-terminal symbol and  is the null string, is ambiguous.
(B) SLR is powerful than LALR.
(C) An LL(1) parser is a top-down parser.
(D) YACC tool is an LALR(1) parser generator.
Answer: B


36.       Consider the reference string
0 1 2 3 0 1 4 0 1 2 3 4
If FIFO page replacement algorithm is used, then the number of page faults with three page frames and four page frames are .......... and ........... respectively.
(A) 10, 9             (B) 9, 9
(C) 10, 10          (D) 9, 10
Answer: D
37.       Suppose there are four processes in execution with 12 instances of a Resource R in a system.
The maximum need of each process and current allocation are given below:
Process
Max. Need
Current Allocation
P1
8
3
P2
9
4
P3
5
2
P4
3
1
With reference to current allocation, is system safe? If so, what is the safe sequence?
(A) No                            (B) Yes, P1 P2 P3 P4
(C) Yes, P4 P3 P1 P2    (D) Yes, P2 P1 P3 P4
Answer: C
38.       If the Disk head is located initially at track 32, find the number of disk moves required with FCFS scheduling criteria if the disk queue of I/O blocks requests are:
98, 37, 14, 124, 65, 67
(A) 320               (B) 322
(C) 321              (D) 319
Answer: C
39.       In UNIX, ............ creates three subdirectories: 'PIS' and two subdirectories 'progs' and ‘data’ from just created subdirectory 'PIS'.
(A) mdkir PIS/progs PIS/data PIS
(B) mkdir PIS progs data
(C) mkdir PIS PIS/progs PIS/data
(D) mkdir PIS/progs data
Answer: C
40.    A scheduling Algorithm assigns priority proportional to the waiting time of a process. Every process starts with priority zero (lowest priority). The scheduler re-evaluates the process priority for every 'T' time units and decides next process to be scheduled. If the process have no I/O operations and all arrive at time zero, then the scheduler implements .............. criteria.
(A) Priority scheduling                        (B) Round Robin Scheduling
(C) Shortest Job First              (D) FCFS
Answer: B


41.       If S1 is total number of modules defined in the program architecture, S3 is the number of modules whose correct function depends on prior processing then the number of modules not dependent on prior processing is:
(A) 1 + S3/S1                 (B) 1 - S3/S1
(C) 1 + S1/S3                 (D) 1 - S1/S3
Answer: B
42.       The ................ model is preferred for software development when the requirements are not clear.
(A) Rapid Application Development            (B) Rational Unified Process
(C) Evolutionary Model                      (D) Waterfall Model
Answer: C
43.       Which of the following is not included in waterfall model ?
(A) Requirement analysis      (B) Risk analysis
(C) Design                                (D) Coding
Answer: B
44.       The cyclomatic complexity of a flow graph V(G), in terms of predicate nodes is:
(A) P + 1                        (B) P - 1
(C) P - 2                         (D) P + 2
Where P is number of predicate nodes in flow graph V(G).
Answer: A
45.       The extent to which a software tolerates the unexpected problems, is termed as:
(A) Accuracy                 (B) Reliability
(C) Correctness           (D) Robustness
Answer: D


46.       An attacker sits between customer and Banker, and captures the information from the customer and retransmits to the banker by altering the information. This attack is called as ..............
(A) Masquerade Attack           (B) Replay Attack
(C) Passive Attack                   (D) Denial of Service Attack
Answer: B
47.       Consider the following two statements:
(a) Business intelligence and Data warehousing is used for forecasting and Data mining.
(b) Business intelligence and Data warehousing is used for analysis of large volumes of sales data.
Which one of the following options is correct?
(A) (a) is true, (b) is false        (B) Both (a) and (b) are true
(C) (a) is false, (b) is true        (D) Both (a) and (b) are false
Answer: B
48.       Pipelining improves performance by:
(A) decreasing instruction latency
(B) eliminating data hazards
(C) exploiting instruction level parallelism
(D) decreasing the cache miss rate
Answer: C
49.       Consider the following two statements :
(a) Data scrubling is a process to upgrade the quality of data, before it is moved into Data warehouse.
(b) Data scrubling is a process of rejecting data from data warehouse to create indexes.
Which one of the following options is correct ?
(A) (a) is true, (b) is false        (B) (a) is false, (b) is true
(C) Both (a) and (b) are false (D) Both (a) and (b) are true
Answer: A
50.    Given the following statements:
(a) Strategic value of data mining is time stamping
(b) Information collection is an expensive process in building an expert system.
Which of the following options is correct ?
(A) Both (a) and (b) are false (B) Both (a) and (b) are true
(C) (a) is true, (b) is false        (D) (a) is false, (b) is true
Answer: B