Computer Science Study Materials for Competitive Exams

Sample Questions, Previous Year Solved Papers, Study Materials For Competitive Examinations Like UGC NET, SET And GATE Computer Science.

Friday, 19 June 2015

61.       Given the recursively enumerable language (LRE), the context sensitive language (LCS), the recursive language (LREC), the context free language (LCF) and deterministic context free language (LDCF). The relationship between these families is given by
Answer: D
62.       Match the following :
List – I                                       List – II
a. Context free grammar         i. Linear bounded automaton
b. Regular grammar                ii. Pushdown automaton
c. Context sensitive grammar iii. Turing machine
d. Unrestricted grammar         iv. Deterministic finite automaton
Codes :
   a   b    c   d
(A) ii    iv   iii   i
(B) ii    iv   i    iii
(C) iv   i    ii    iii
(D) i    iv   iii   ii
Answer: B
63.       According to pumping lemma for context free languages :
Let L be an infinite context free language, then there exists some positive integer m such that any w Î L with |w|³m can be decomposed as w = u v x y z
(A) with | vxy | £ m such that uvi xyi  zÎL for all i = 0, 1, 2
(B) with | vxy | £ m, and | vy | ³ 1, such that uvi xyi  zÎL for all i = 0, 1, 2, …….
(C) with | vxy | ³ m, and | vy | £ 1, such that uvi xyi  zÎL for all i = 0, 1, 2, …….
(D) with | vxy | ³ m, and | vy | ³ 1, such that uvi xyi  zÎL for all i = 0, 1, 2, …….
Answer: B
64.       Given two spatial masks
The Laplacian of an image at all points (x, y) can be implemented by convolving the image with spatial mask. Which of the following can be used as the spatial mask ?
(A) only S1                           (B) only S2
(C) Both S1 and S2        (D) None of these
Answer: B
65.       Given a simple image of size 10 × 10 whose histogram models the symbol probabilities and is given by
The first order estimate of image entropy is maximum when
(A) a = 0, b = 0, c = 0, d = 1
(B) a =1/2, b =1/2, c = 0, d = 0
(C) a =1/3, b =1/3, c =1/3, d = 0
(D) a =1/4, b =1/4, c =1/4, d =1/4
Answer: D
66.       A Butterworth lowpass filter of order n, with a cutoff frequency at distance D0 from the origin, has the transfer function H(u, v) given by
Answer: A
67.       If an artificial variable is present in the ‘basic variable’ column of optimal simplex table, then the solution is
(A) Optimum                 (B) Infeasible
(C) Unbounded           (D) Degenerate
Answer: B
68.       The occurrence of degeneracy while solving a transportation problem means that
(A) total supply equals total demand
(B) total supply does not equal total demand
(C) the solution so obtained is not feasible
(D) none of these
Answer: C
69.       Five men are available to do five different jobs. From past records, the time (in hours) that each man takes to do each job is known and is given in the following table :
Find out the minimum time required to complete all the jobs.
(A) 5       (B) 11
(C) 13     (D) 15
Answer: C
70.    Consider the following statements about a perception :
I. Feature detector can be any function of the input parameters.
II. Learning procedure only adjusts the connection weights to the output layer.
Identify the correct statement out of the following :
(A) I is false and II is false.     (B) I is true and II is false.
(C) I is false and II is true.      (D) I is true and II is true.
Answer: D
71.    A ............... point of a fuzzy set A is a point xÎX at which μA(x) = 0.5
(A) core              (B) support
(C) crossover    (D) a-cut
Answer: C
72.    Match the following learning modes w.r.t. characteristics of available information for learning :
a. Supervised                           i. Instructive information on desired responses, explicitly specified by a teacher.
b. Recording                 ii. A priori design information for memory storing
c. Reinforcement         iii. Partial information about desired responses, or only “right” or “wrong” evaluative information
d. Unsupervised          iv. No information about desired responses
Codes :
  a   b    c    d
(A) i    ii    iii   iv
(B) i    iii   ii    iv
(C) ii   iv   iii   i
(D) ii   iii   iv   i
Answer: A
73.    Which of the following versions of Windows O.S. contain built-in partition manager which allows us to shrink and expand pre-defined drives ?
(A) Windows Vista       (B) Windows 2000
(C) Windows NT          (D) Windows 98
Answer: A
74.    A Trojan horse is
(A) A program that performs a legitimate function that is known to an operating system or its user and also has a hidden component that can be used for nefarious purposes like attacks on message security or impersonation.
(B) A piece of code that can attach itself to other programs in the system and spread to other systems when programs are copied or transferred.
(C) A program that spreads to other computer systems by exploiting security holes like weaknesses in facilities for creation of remote processes
(D) All of the above
Answer: A
75.    Which of the following computing models is not an example of distributed computing environment ?
(A) Cloud computing              (B) Parallel computing
(C) Cluster computing            (D) Peer-to-peer computing
Answer: B

51.       Consider an imaginary disk with 40 cylinders. A request come to read a block on cylinder 11. While the seek to cylinder 11 is in progress, new requests come in for cylinders 1, 36, 16, 34, 9 and 12 in that order. The number of arm motions using shortest seek first algorithm is
(A) 111   (B) 112
(C) 60     (D) 61
Answer: D
52.       An operating system has 13 tape drives. There are three processes P1, P2 & P3. Maximum requirement of P1 is 11 tape drives, P2 is 5 tape drives and P3 is 8 tape drives. Currently, P1 is allocated 6 tape drives, P2 is allocated 3 tape drives and P3 is allocated 2 tape drives. Which of the following sequences represent a safe state ?
(A) P2 P1 P3    (B) P2 P3 P1
(C) P1 P2 P3    (D) P1 P3 P2
Answer: A
53.       Monitor is an Interprocess Communication (IPC) technique which can be described as
(A) It is higher level synchronization primitive and is a collection of procedures, variables, and data structures grouped together in a special package.
(B) It is a non-negative integer which apart from initialization can be acted upon by wait and signal operations.
(C) It uses two primitives, send and receive which are system calls rather than language constructs.
(D) It consists of the IPC primitives implemented as system calls to block the process when they are not allowed to enter critical region to save CPU time.
Answer: A
54.       In a distributed computing environment, distributed shared memory is used which is
(A) Logical combination of virtual memories on the nodes.
(B) Logical combination of physical memories on the nodes.
(C) Logical combination of the secondary memories on all the nodes.
(D) All of the above
Answer: B
55.       Equivalent logical expression for the Well Formed Formula (WFF),
~("x) F[x]
(A) "x (~F[x])    (B) ~($x) F[x]
(C) $x (~F[x])     (D) "x F[x]
Answer: C

56.       An A* algorithm is a heuristic search technique which
(A) is like a depth-first search where most promising child is selected for expansion
(B) generates all successor nodes and computes an estimate of distance (cost) from start node to a goal node through each of the successors. It then chooses the successor with shortest cost.
(C) saves all path lengths (costs) from start node to all generated nodes and chooses shortest path for further expansion.
(D) none of the above
Answer: B
57.       The resolvent of the set of clauses
(A Ú B, ~A Ú D, C Ú ~B) is
(A) A Ú B           (B) C Ú D
(C) A Ú C           (D) A Ú D
Answer: B
58.       Match the following :
a. Script                                                 i. Directed graph with labelled nodes for graphical                               representation of knowledge
b. Conceptual Dependencies           ii. Knowledge about objects and events is stored in record-like structures consisting of slots and slot values.
c. Frames                                              iii. Primitive concepts and rules to represent natural                            language statements
d. Associative Network                                   iv. Frame like structures used to represent stereotypical patterns for commonly occurring events in terms of actors, roles, props and scenes
Codes :
   a    b   c   d
(A) iv    ii    i   iii
(B) iv   iii   ii    i
(C) ii    iii   iv   i
(D) i    iii    iv   ii
Answer: B
59.       Match the following components of an expert system :
a. I/O interface                                      i. Accepts user’s queries and responds to question through
I/O interface
b. Explanation module           ii. Contains facts and rules about the domain
c. Inference engine                             iii. Gives the user, the ability to follow inferencing steps at any time during consultation
d. Knowledge base                             iv. Permits the user to communicate with the system in a natural way
Codes :
  a    b   c   d
(A) i    iii   iv   ii
(B) iv  iii    i    ii
(C) i    iii   ii   iv
(D) iv   i    iii  ii
Answer: B
60.       A computer based information system is needed :
I. as it is difficult for administrative staff to process data.
II. due to rapid growth of information and communication technology.
III. due to growing size of organizations which need to process large volume of data.
IV. as timely and accurate decisions are to be taken.
Which of the above statement(s) is/are true ?
(A) I and II
(B) III and IV
(C) II and III
(D) II and IV
Answer: B