Monday, 9 October 2017

UGC Net Computer Science Paper 3 Dec 13 Solved Page 6

UGC Net Computer Science Paper 3 Dec 13 Solved Page 6
51. Synchronization is achieved by a timing device called a ________ which generates a periodic train of ________.
(A) clock generator, clock pulse
(B) master generator, clock pulse
(C) generator, clock
(D) master clock generator, clock pulse



52. Serial access memories are useful in applications where
(A) Data consists of numbers
(B) Short access time is required
(C) Each stored word is processed differently.
(D) None of these

53. What will be the output of the following logic diagram ?

(A) x OR y
(B) x AND y
(C) x XOR y
(D) x XNOR y

54. The essential difference between traps and interrupts is
(A) traps are asynchronous and interrupts are synchronous with the program.
(B) traps are synchronous and interrupts are asynchronous with the program.
(C) traps are synchronous and interrupts are asynchronous with the I/O devices.
(D) None of these.

55. Consider the following ER diagram :

The minimum number of tables required to represent M, N, P, R1, R2 is
(A) 2
(B) 3
(C) 4
 (D) 5

56. Consider the following schemas :
Branch = (Branch-name, Assets,
Branch-city)
Customer = (Customer-name, Bank
name, Customer-city)
Borrow = (Branch-name, loan
number, customer account-number)
Deposit = (Branch-name, Accountnumber,
Customer-name, Balance)
Using relational Algebra, the Query
that finds customers who have
balance more than 10,000 is _______

(A) πcustomer-name (σbalance >10000(Deposit)
(B) σcustomer-name (σbalance >10000(Deposit)
(C) πcustomer-name (σbalance >10000(Borrow)
(D) σcustomer-name (πbalance >10000(Borrow)

57. Find the false statement :
(A) The relationship construct known as the weak relationship type was defined by Dey,Storey & Barron (1999)
(B) A weak relationship occurs when two relationship types are linked by either Event- Precedent sequence or Condition-Precedent sequence.
(C) Conceptual model is not accurate representation of “Universe of interest”.
(D) Ternary, Quaternary and Quintary relationships are shown through a series of application scenario’s and vignette’s.


58. Consider the table Student (stuid, name, course, marks).Which one of the following two
queries is correct to find the highest marks student in course 5 ?
Q.1. Select S.stuid
From student S
Where not exists
(select ∗ from student e where
e course = ‘5’ and e marks ≥ s
marks)
Q.2. Select s.stu.id
From student S
Where s ⋅ marks > any
(select distinct marks from
student S where s ⋅ course = 5)
(A) Q. 1
(B) Q. 2
(C) Both Q. 1 and Q. 2
(D) Neither Q. 1 nor Q. 2


59. Armstrong (1974) proposed systematic approach to derive functional dependencies. Match the
following w.r.t. functional dependencies :

List-I
List-II
a. Decomposition
rule
i. If X Y and
Z W then
{X, Z} {Y, W}
b. Union rule
ii. If X Y and
{Y, W}Z then
{X, W} Z
c. Composition
rule
iii. If X Y and XZ
then X {Y, Z}
d. Pseudo
transitivity
rule
iv. If X {Y, Z}
then X Y and
X Z

Codes :
       a b c d
(A) iii ii iv i
(B) i iii iv ii
(C) ii i iii iv
(D) iv iii i ii

60. Match the following :

List-I
List-II
a. Secondary
Index
i. Functional
Dependency
b. Nonprocedural
Query
Language
ii. B-Tree
c. Closure of
set of
Attributes
iii. Relational Algebraic
Operation
d. Natural
JOIN
iv. Domain Calculus

Codes :
       a b c d
(A) i ii iv iii
(B) ii i iv iii
(C) i iii iv ii
(D) ii iv i iii