Thursday, May 10, 2012

UGC NET Computer Science and Application December 2006 Solution

Computer Science and Applications
Note :   This paper contains fifty (50) objective-type questions, 
each question carrying two (2) marks. Attempt all of them.

1.   Which of the regular expressions corresponds to this grammar ?
      S → AB/AS, A → a/aA, B → b
     (A)   aa*b +            (B)    aa*b           (C)  (ab)*        (D)   a(ab)*

2.   The proposition ~ q ∨ p is equivalent to :
     (A)                     (B)                      (C)                    (D)

3.   The number of edges in a complete graph with N vertices is equal to :
     (A) N (N−1)       (B) 2N−1           (C) N−1     (D)   N(N−1)/2

4.   Which of the following is not true ?
     (B)    A − B =A ∩ ~ B

5.   If (a2−b2) is a prime number where a and b  belongs to N, then :
     (A) a2−b2=3                                (B) a2−b2=a−b
     (C) a2−b2=a+b                              (D) a2−b2=5
Here, a2-b2=prime
==> (a+b)*(a-b)=some_prime*1
==> a+b=some_prime; a-b must be =1 

6.   The hexadecimal equivalent of (10111)2×(1110)2 is :
     (A) 150                 (B) 241                  (C) 142     (D)   101011110 
7.   An example of a self complementing code is :
     (A) 8421 code                              (B) Gray code
     (C) Excess-3 code                        (D) 7421 code

8.   A sum of products expression can be implemented with __________ logic gates.
     (A) AND − OR                               (B) NAND − OR
     (C) AND − NOT                              (D) OR − AND

9.   The characteristic equation of the D flip-flop is :
     (A)                     (B)    Q=D               (C)  Q=1        (D)   Q=0

10. Which of the following logic is the fastest ?
    (A)    RTL                (B)   ECL             (C)    HTL        (D)    HCL

11. When a function is recursively called, all automatic variables :
    (A)    are initialized during each execution of the function
    (B)    are retained from the last execution
    (C)    are maintained in a stack
    (D)    are ignored

12. Enumeration variables can be used in :
    (A)    search statement like an integer variable
    (B)    break statement
    (C)    preprocessor commands
    (D)    function statement

13. int arr[ ]={1, 2, 3, 4}
    int count;
    incr( ) {return ++count;}
    main( )
        arr[count ++]=incr( );
       printf(“arr[count]=%d\n”, arr[count]);
    The value printed by the above program is :
    (A)    1                  (B)   2               (C)    3              (D)    4

14. When one-dimensional character array of unspecified length is assigned an initial
    value :
    (A)    an arbitrary character is automatically added to the end of the string
    (B)    ‘o’ is added to the end of the string
    (C)    length of the string is added to the end of the string
    (D)    ‘end’ is added to the end of the string
15. The declaration “unsigned u” indicates :
    (A)    u is an unsigned character
    (B)    u is an unsigned integer
    (C)    u is a character
    (D)    u is a string

16. Which possibility among the following is invalid in case of a Data Flow Diagram ?
    (A) A process having in-bound data flows more than out-bound data flows
    (B) A data flow between two processes
    (C) A data flow between two data stores
    (D) A data store having more than one in-bound data flows

17. In DBMS, deferred update means :
    (A) All the updates are done first but the entries are made in the log file later
    (B) All the log files entries are made first but the actual updates are done later
    (C) Every update is done first followed by a writing on the log file
    (D) Changes in the views are deferred till a query asks for a view

18. Which statement is false regarding data independence ?
    (A) Hierarchical data model suffers from data independence
    (B) Network model suffers from data independence
    (C) Relational model suffers only from logical data independence
    (D) Relational model suffers only from physical data independence

19. Which of the following tools is not required during system analysis phase of system
    development life cycle ?
    (A) Case tool                             (B) RAD tool
    (C) Reverse engineering                   (D) None of these

20. Two  phase protocol in a database management system is :
    (A)  a concurrency mechanism that is not deadlock free
    (B)  a recovery protocol used for restoring a database after a crash
    (C)  Any update to the system log done in 2-phases
    (D)  not effective in Database

21. Which algorithm has same average, worst case and best case time ?
    (A) Binary search                         (B) Maximum of n number
    (C) Quick sort                            (D) Fibonacci search

22. Binary search tree is an example of :
    (A) Divide and conquer technique
    (B) Greedy algorithm
    (C) Back tracking
    (D) Dynamic Programming

23. What is the time required to insert an element in a stack 
with linked implementation ?
    (A) O (log2n)           (B) O (n)              (C) O (n log2n)     (D) O (1)

24. The equivalent postfix expression for d (e+ f) +b*c :
    (A)  defbc/++*                     (B)    def+/bc+*
    (C)  def+/bc *+                    (D)    None of these

25. Which one of the following is a physical data structure ?
    (A) Array                          (B) Linked lists
    (C) Stacks                         (D) Tables

26. How many DS1 signals are transported on a DS3 signal ?
    (A) 24                 (B) 672                 (C) 14                (D) 28

27. A 10 BASE-2 network is limited to :
    (A) 20 bytes per data field               (B)  30 stations per segment
    (C) 40 segments                                (D)  50 feet of cable

28. The network is a :
    (A) Class A Network                       (B)  Class B Network
    (C) Class C Network                       (D)  Class D Network

29. The subnet mask
    (A)  Extends the network portion to 16 bits
    (B)  Extends the network portion to 26 bits
    (C)  Extends the network portion to 36 bits
    (D)  Has no effect on the network portion of an IP address

30. The LAPB frame structure and the frame structure of SDLC are :
    (A) Opposite                              (B) Identical
    (C) Reversed                              (D) Non-identical

31. Linking :
    (A) cannot be performed before relocation
    (B) cannot be performed after relocation
    (C) can be performed both before and after relocation
    (D) is not required if relocation is performed

32. Which of the following is the most general phase-structured grammar ?
    (A) Regular                               (B) Context-sensitive
    (C) Context free                       (D) Syntax tree

33. A compiler for a high level language that runs on one machine and produces code for
    a different machine is called :
    (A) Optimizing                          (B) One pass compiler
    (C) Cross compiler                      (D) Multipass compiler

34. The ‘K’ in LR (R) cannot be :
    (A) 0                  (B) 1                 (C)   2     (D)  None of these

35. Peer-hole optimization is a form of :
    (A) loop optimization                   (B)  local optimization  (C) constant folding                    (D)  data flow analysis

36. An operating system is :
    (A) Collection of hardware components (B)   Collection of input-output devices
    (C) Collection of software routines          (D)   All the above

37. ____________ is one of pre-emptive scheduling algorithm.
    (A) Shortest-Job-first                  (B) Round-robin
    (C) Priority based                      (D) Shortest-Job-next

38. A software to create a Job Queue is called ____________ .
    (A) Linkage editor                      (B) Interpreter
    (C) Driver                                    (D) Spooler

39. A permanent database of a general model of compiler is ____________ .
    (A) Identifier table                    (B) Page map table
    (C) Literal table                        (D) Terminal table

40. Loading operating system from secondary memory to primary memory is called
    ____________ .
    (A) Compiling                           (B) Booting   
    (C) Refreshing                          (D) Reassembling

41. Software Cost Performance index (CPI) is given by : 
(A) BCWP /ACWP                               (B)ACWP
 (C) BCWP−ACWP                           (D) BCWP−BCWS
    Where :     BCWP stands for Budgeted Cost of Work Performed
                BCWS stands for Budget Cost of Work Scheduled
                ACWP stands for Actual Cost of Work Performed

42. Software Risk estimation involves following two tasks :
    (A) risk magnitude and risk impact
    (B) risk probability and risk impact
    (C) risk maintenance and risk impact
    (D) risk development and risk impact

43. In a object oriented software design, ‘Inheritance’ is a kind of __________ .
    (A) relationship                     (B) module
    (C) testing                             (D) optimization

44. Reliability of software is directly dependent on :
    (A) quality of the design
    (B) number of errors present
    (C) software engineer’s experience
    (D) user requirement

45. ‘Abstraction’ is ____________ step of Attribute in a software design.
    (A) First                (B) Final           (C) Last             (D)  Middle

46. The frequency band allocated for the downlink in GSM is :
    (A) 960 - 985 MHz                    (B) 935 - 960 MHz
    (C) 920 - 945 MHz                    (D) 930 - 955 MHz

47. Which of the following is an EDI standard ?
    (A) ANSI X.15                        (B) ANSI X.14
    (C) ANSI X.13                         (D) ANSI X.12

48. An INT file in Windows 95 is :
    (A) a program file                   (B)  a message file
    (C) a text file                           (D)  link file

49. Link analysis operation in data mining uses ___________ technique.
    (A) Classification                   (B) Association discovery
    (C) Visualisation                     (D) Neural clustering

50. The maximum size of SMS in IS-95 is ______ octets.
    (A) 120                  (B) 95                  (C) 128              (D)  64

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