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.

Monday, 31 August 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: C

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 
      (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 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

Sunday, 30 August 2015

Questions 50 to 52 are based on the following data:

Measurements of some variable X were made at an interval of 1 minute from 10 A.M. to 10:20 A.M. The data, thus, obtained is as follows:
X :60, 62, 65, 64, 63, 61, 66, 65, 70, 68, 63, 62, 64, 69, 65, 64, 66, 67, 66, 64

50.       The value of X, which is exceeded 10% of the time in the duration of measurement, is
(A) 69     (B) 68
(C) 67     (D) 66
51.       The value of X, which is exceeded 90% of the time in the duration of measurement, is
(A) 63     (B) 62
(C) 61     (D) 60
52.       The value of X, which is exceeded 50% of the time in the duration of measurement, is
(A) 66     (B) 65
(C) 64     (D) 63
53.       For maintaining an effective discipline in the class, the teacher should
(A) Allow students to do what they like.
(B) Deal with the students strictly.
(C) Give the students some problem to solve.
(D) Deal with them politely and firmly.
Answer: C
54.       An effective teaching aid is one which
(A) is colourful and good looking     (B) activates all faculties
(C) is visible to all students                (D) easy to prepare and use
Answer: B
55.       Those teachers are popular among students who
(A) develop intimacy with them
(B) help them solve their problems
(C) award good grades
(D) take classes on extra tuition fee
Answer: B

56.       The essence of an effective classroom environment is
(A) a variety of teaching aids (B) lively student-teacher interaction
(C) pin-drop silence                (D) strict discipline
Answer: B
57.       On the first day of his class, if a teacher is asked by the students to introduce himself, he should
(A) ask them to meet after the class
(B) tell them about himself in brief
(C) ignore the demand and start teaching
(D) scold the student for this unwanted demand
Answer: B
58.       Moral values can be effectively inculcated among the students when the teacher
(A) frequently talks about values
(B) himself practices them
(C) tells stories of great persons
(D) talks of Gods and Goddesses
Answer: B
59.    The essential qualities of a researcher are
(A) spirit of free enquiry
(B) reliance on observation and evidence
(C) systematization or theorizing of knowledge
(D) all the above
Answer: D
60.    Research is conducted to
I. Generate new knowledge
II. Not to develop a theory
III. Obtain research degree
IV. Reinterpret existing knowledge
Which of the above are correct?
(A) I, III & II         (B) III, II & IV
(C) II, I & III        (D) I, III & IV
Answer: D

41.       The first Open University in India was set up in the State of
(A) Andhra Pradesh                (B) Delhi
(C) Himachal Pradesh                        (D) Tamil Nadu
Answer: A
42.       Most of the Universities in India are funded by
(A) the Central Government 
(B) the State Governments
(C) the University Grants Commission
(D) Private bodies and Individuals
Answer: C
43.       Which of the following organizations looks after the quality of Technical and Management education in India?
(A) NCTE          (B) MCI
(C) AICTE         (D) CSIR
Answer: C
44.       Consider the following statements:
Identify the statement which implies natural justice.
(A) The principle of natural justice is followed by the Courts.
(B) Justice delayed is justice denied.
(C) Natural justice is an inalienable right of a citizen
(D) A reasonable opportunity of being heard must be given.
Answer: D
45.       The President of India is
(A) the Head of State
(B) the Head of Government
(C) both Head of the State and the Head of the Government
(D) None of the above
Answer: A

46.       Who among the following holds office during the pleasure of the President of India?
(A) Chief Election Commissioner
(B) Comptroller and Auditor General of India
(C) Chairman of the Union Public Service Commission
(D) Governor of a State
Answer: D
Questions 47 to 49 are based upon the following diagram in which there are three interlocking circles A, P and S where A stands for Artists, circle P for Professors and circle S for Sports persons.
Different regions in the figure are lettered from a to f:
47.       The region which represents artists who are neither sportsmen nor professors.
(A) d       (B) e
(C) b       (D) g
Answer: B
48.       The region which represents professors, who are both artists and sportspersons.
(A) a       (B) c
(C) d       (D) g
Answer: A
49.       The region which represents professors, who are also sportspersons, but not artists.
(A) e       (B) f
(C) c       (D) g
Answer: C

31.       DNS in internet technology stands for
(A) Dynamic Name System               (B) Domain Name System
(C) Distributed Name System            (D) None of these
Answer: B
32.       HTML stands for
(A) Hyper Text Markup Language
(B) Hyper Text Manipulation Language
(C) Hyper Text Managing Links
(D) Hyper Text Manipulating Links
Answer: A
33.       Which of the following is type of LAN?
(A) Ethernet      (B) Token Ring
(C) FDDI            (D) All of the above
Answer: D
34.       Which of the following statements is true?
(A) Smart cards do not require an operating system.
(B) Smart cards and PCs use some operating system.
(C) COS is smart card operating system.
(D) The communication between reader and card is in full duplex mode.
Answer: C
35.       The Ganga Action Plan was initiated during the year
(A) 1986                        (B) 1988
(C) 1990                        (D) 1992
Answer: A

36.       Identify the correct sequence of energy sources in order of their share in the power sector in India:
(A) Thermal > nuclear > hydro > wind
(B) Thermal > hydro > nuclear > wind
(C) Hydro > nuclear > thermal > wind
(D) Nuclear > hydro > wind > thermal
Answer: B
37.       Chromium as a contaminant in drinking water in excess of permissible levels, causes
(A) Skeletal damage                          
(B) Gastrointestinal problem
(C) Dermal and nervous problems  
(D) Liver/Kidney problems
Answer: D
38.       The main precursors of winter smog are
(A) N2O and hydrocarbons    (B) NOx and hydrocarbons
(C) SO2 and hydrocarbons    (D) SO2 and ozone
Answer: C
39.       Flash floods are caused when
(A) the atmosphere is convectively unstable and there is considerable vertical wind shear
(B) the atmosphere is stable
(C) the atmosphere is convectively unstable with no vertical windshear
(D) winds are catabatic
Answer: A
40.    In mega cities of India, the dominant source of air pollution is
(A) transport sector                  (B) thermal power
(C) municipal waste                (D) commercial sector
Answer: A