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.

Tuesday, 14 May 2019

NTA UGC NET Computer Science Paper II December 2018 - Part 5

81.       Data scrubbing is
(1) A process to reject data from the data warehouse and to create the necessary indexes.
(2) A process to load the data in the data warehouse and to create the necessary indexes.
(3) A process to upgrade the quality of data after it is moved into a data warehouse.
(4) A process to upgrade the quality of data before it is moved into a data warehouse.
Answer: 4
82.       Consider the relation schema R = (A,B,C,D,E,F) on which the following functional dependencies hold:
A → B
B, C → D
E → C
D → A
What are the candidate keys of R?
(1) AE and BE
(2) AE, BE and DE
(3) AEF, BEF and BCF
(4) AEF, BEF and DEF
Answer: 4
83.       Consider the following sequence of two transactions on a bank account (A) with initial balance 20,000 that transfers 5,000 to another account (B) and then apply 10% interest.
(i) T1 start
(ii) T1 A old = 20,000 new 15,000
(iii) T1 B old = 12,000 new = 17,000
(iv) T1 commit
(v) T2 start
(vi) T2 A old = 15,000 new = 16,500
(vii) T2 commit
Suppose the database system crashes just before log record (vii) is written. When the system is restarted, which one statement is true of the recovery process?
(1) We must redo log record (vi) to set A to 16,500.
(2) We must redo log record (vi) to set A to 16,500 and then redo log records (ii) and (iii).
(3) We need not redo log records (ii) and (iii) because transaction T1 is committed.
(4) We can apply redo and undo operations in arbitrary order because they are idempotent.
Answer: 2
84.       Consider the following tables (relations):
Primary keys in the tables are shown using underline. Now, consider the following query:
SELECT S.Name, Sum (P.Marks)
FROM Students S, Performance P
WHERE S.Roll-No = P.Roll-No
GROUP BY S.Name
The number of rows returned by the above query is
(1) 0
(2) 1
(3) 2
(4) 3
Answer: 3
85.       A clustering index is defined on the fields which are of type:
(1) non-key and ordering
(2) non-key and non-ordering
(3) key and ordering
(4) key and non-ordering
Answer: 1
86.       A host is connected to a department network which is part of a university network. The university network, in turn, is part of the Internet. The largest network, in which the Ethernet address of the host is unique, is
(1) the Internet
(2) the university network
(3) the department network
(4) the subnet to which the host belongs
Answer: 1
87.       An Internet Service Provider (ISP) has following chunk of CIDR-based IP addresses available with it :245.248.128.9./20. The ISP wants to give half of this chunk of addresses to organization A and a quarter to organization B while retaining the remaining with itself. Which of the following is a valid allocation of addresses to A and B?
(1) 245.248.136.0/21 and 245.248.128.0/22
(2) 245.248.128.0/21 and 245.248.128.0/22
(3) 245.248.132.0/22 and 245.248.132.0/21
(4) 245.248.136.0/24 and 245.248.132.0/21
Answer: 1
88.       Consider the following two statements:
S1: TCP handles both congestion and flow control
S2: UDP handles congestion but not flow control
Which of the following options is correct with respect to the above statements (S1) and (S2)?
Choose the correct answer from the code given below:
Code:
(1) Neither S1 nor S2 is correct
(2) S1 is not correct but S2 is correct
(3) S1 is correct but S2 is not correct
(4) Both, S1 and S2 are correct
Answer: 3
89.       Identify the correct sequence in which the following packets are transmitted on the network by a host when a browser requests a webpage from a remote server, assuming that the host has just been restarted.
(1) HTTP GET request, DNS query, TCP SYN
(2) DNS query, HTTP GET request, TCP SYN
(3) TCP SYN, DNS query, HTTP GET request
(4) DNS query, TCP SYN, HTTP GET request
Answer: 4
90.    Suppose that everyone in a group of N people wants to communicate secretly with (N−1) other people using symmetric key cryptographic system. The communication between any two persons should not be decodable by the others in the group. The number of keys required in the system as a whole to satisfy the confidentiality requirement is
(1) N(N−1)
(2) N(N−1)/2
(3) 2N
(4) (N−1)2
Answer: 2
91.    An agent can improve its performance by
(1) Perceiving
(2) Responding
(3) Learning
(4) Observing
Answer: 3
92.    Which of the following is true for semi-dynamic environment?
(1) The environment may change while the agent is deliberating.
(2) The environment itself does not change with the passage of time but the agent’s performance score does.
(3) Even if the environment changes with the passage of time while deliberating, the performance score does not change.
(4) Environment and performance score, both change simultaneously.
Answer: 2
93.    Consider the following terminology and match List I with List II and choose the correct answer from the code given below.
b = branching factor
d = depth of the shallowest solution
m = maximum depth of the search tree
l = depth limit
List I                                           List II
(Algorithms)                            (Space Complexity)
(a) BFS search                         (i) O(bd)
(b) DFS search                                    (ii) O(bd)
(c) Depth-limited search         (iii) O(bm)
(d) Iterative deepening search (iv) O(bl)
Code:
(1) (a) – (i), (b)-(ii), (c)-(iv), (d)-(iii)
(2) (a) – (ii), (b)-(iii), (c)-(iv), (d)-(i)
(3) (a) – (iii), (b)-(ii), (c)-(iv), (d)-(i)
(4) (a) – (i), (b)-(iii), (c)-(iv), (d)-(ii)
Answer: 2
94.    Match List I with List II and choose the correct answer from the code given below.
List I                                                       List II
(a) Greedy Best-First Search             (i) Selects a node for expansion
if optimal path to that node has
been found
(b) A* Search                                        (ii) Avoids substantial overhead
associated with keeping the
sorted queue of nodes
(c ) Recursive Best-First Search       (iii) Suffers from excessive node
generation
(d) Iterative-deepening A* Search    (iv) Time complexity depends
on the quality of heuristic.
Code:
(1) (a) – (i), (b)-(ii), (c)-(iii), (d)-(iv)
(2) (a) – (iv), (b)-(i), (c)-(ii), (d)-(iii)
(3) (a) – (iv), (b)-(iii), (c)-(ii), (d)-(i)
(4) (a) – (i), (b)-(iv), (c)-(iii), (d)-(ii)
Answer: 4
95.    Consider the following statements:
S1: A heuristic is admissible if it never overestimates the cost to reach the goal.
S2: A heuristic is monotonous if it follows triangle inequality property.
Which of the following is true referencing the above statements?
Choose the correct answer from the code given below:
Code:
(1) Neither of the statements S1 and S2 are true
(2) Statement S1 is false but statement S2 is true
(3) Statement S1 is true but statement S2 is false
(4) Both the statements S1 and S2 are true
Answer: 4
96.    Consider the following statements related to AND-OR Search algorithm.
S1: A solution is a subtree that has a goal node at every leaf.
S2: OR nodes are analogous to the branching in a deterministic environment.
S3: AND nodes are analogous to the branching in a non-deterministic environment.
Which of the following is true referencing the above statements?
Choose the correct answer from the code given below:
Code:
(1) S1 – False, S2 – True, S3 – True
(2) S1 – True, S2 – True, S3 – False
(3) S1 – True, S2 – True, S3 – True
(4) S1 – False, S2 – True, S3 – False
Answer: 3
97.    Consider the following minimax game tree search
What will be the value propagated at the root?
(1) 3
(2) 4
(3) 5
(4) 6
Answer: 3
98.    Consider a vocabulary with only four propositions A, B, C and D. How many models are there for the following sentence?
¬A ¬B ¬C ¬D
(1) 7
(2) 8
(3) 15
(4) 16
Answer: 3
99.    Consider the sentence below:
“There is a country that borders both India and Nepal”
Which of the following represents the above sentence correctly?
(1) c Country(c) Border(c,India) Border(c,Nepal)
(2) c Country(c) [Border(c,India) Border(c,Nepal)]
(3) [c Country(c)] [Border(c,India) Border(c,Nepal)]
(4) c Border(Country(c),India) Nepal)
Answer: 1
100.    A full joint distribution for the Toothache, Cavity and Catch is given in the table below.
What is the probability of Cavity, given evidence of Toothache?
(1) <0.2,0.8>
(2) <0.4,0.8>
(3) <0.6,0.8>
(4) <0.6,0.4>
Answer: 4

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