UGC NET computer science questions and answers
UGC NET (computer science)
previous years question answer
Q.1 Data warehouse contains___________ data that is never found in operational environment.
A Scripted
B Encoded
C Encrypted
D Summary
UGC NET CS 2018 Dec – II
Question Explanation:
Data Warehouse is a relational database that is designed for query and analysis rather than for transaction processing. It usually contains historical data derived from transaction data, but it can include data from other sources. The goal is to produce statistical results that may help in decision makings.
Option (D) is correct.
Q. 2 Suppose a system has 12 instances of some resources with n processes competing for that resource. Each process may require 4 instances of the resource. The maximum value of n for which the system never enters into deadlock is
A 3 B 4 C 5 D 6
UGC NET CS 2018 Dec – II
Explanation:
Given, Number of resources (R) = 12 Max need for each resource (N) = 3 Since deadlock-free condition is:
R ≥ P(N − 1) + 1
Where R is total number of resources, P is the number of processes, and N is the max need for each resource.
12 ≥ P(4 − 1) + 1
11 ≥ 3P
11/3 ≥ P
P ≤ 3.66 (Take, floor value for maximum) Option (A) is correct.
Q.3 To overcome difficulties in Readers-Writers problem, which of the following statement/s is/are true ?
1 Writers are given exclusive access to shared objects
2 Readers are given exclusive access to shared objects
3 Both readers and writers are given exclusive access to shared objects.
Choose the correct answer from the code given below:
A 1 only B Both 2 and 3
C 2 only D 3 only
UGC NET CS 2018 Dec – II
Explanation:
In Readers-Writers Problem, since readers do not modify values, so these can be allowed with other readers. But writers are given exclusive access to shared objects. Only statement (1) is correct.
Q.4 The boolean expression A’⋅B + A⋅B’ + A⋅B is equivalent to
A A’⋅B
B (A + B)’
C A⋅B
D A + B
Explanation
A'.B + A.B' + A.B
=A'.B + A.B + A.B'
=B(A' + A) + A.B'
=B + A.B'
=(B+A).(B+B')
=B+A
Can also be solved using K-map very easily
Q. 5 In computers, subtraction is generally carried out by
A 9’s complement
B 1’s complement
C 10’s complement
D 2’s complement
Q. 6 The Octal equivalent of the binary number 1011101011 is:
(1) 7353
(2) 1353
(3) 5651
(4) 5657
Answer: 2
Explanation:
Group all the bits in the binary number in sets of three, starting from the right.
Add zeros to the left of the last digit if you don't have enough digits to make a set of three.
Original Binary: 1011101011
Grouping: 1 011 101 011
Adding Zeros for Groups of Three: 001 011 101 011
001=1, 011=3, 101=5, 011=3
So final answer= 1353
Q.7 Which of the following is/are true with reference to 'view' in DBMS?
(a) A 'view' is a special stored procedure executed when certain event occurs.
(b) A 'view' is a virtual table, which occurs after executing a pre-compiled query.
(1) Only (a) is true
(2) Only (b) is true
(3) Both (a) and (b) are true
(4) Neither (a) nor (b) are true
Answer: 2
Q. 8 In SQL, .................. is an Aggregate function.
(1) SELECT
(2) CREATE
(3) AVG
(4) MODIFY
Answer: 3
Q.9 ……command that lets you change one or more fields in a record is
A. Insert
B. Modify
C. Look-up
D. All of the above
Answer: B
Explanation:
Sometimes we need to change the data type of a column. To do this, we use the ALTER TABLE Modify Column command.
Sytax:
ALTER TABLE table_name
MODIFY column_name "New Data Type"
Q.10 The following numbers are inserted into an empty binary search tree in the given order: 10, 1, 3, 5, 15, 12, 16. What is the height of the binary search tree (the height is the maximum distance of a leaf node from the root)?
A) 2 B) 3 C)4 D) 6
Answer: B)
Explanation: Constructed binary search tree will be..
10
/ \
1 15
\ / \
3 12 16
\
5
Q.11 What is Granularity?
(A) The size of database
(B) The size of data item
(C) The size of record
(D) The size of file
Answer: B
Q.12 If the pixels of an image are shuffled then the parameter that may change is
(A) Histogram
(B) Mean
(C) Entropy
(D) Covariance
Answer: D
Q.13 The ………….. memory allocation function modifies the previous allocated space.
(A) calloc( )
(B) free( )
(C) malloc( )
(D) realloc( )
Answer:D
Q.14The mechanism that binds code and data together and keeps them secure from outside world is known as
(A) Abstraction
(B) Inheritance
(C) Encapsulation
(D) Polymorphism
Answer:C
Q.15 Which of the following IP address class is a multicast address?
(A) Class A
(B) Class B
(C) Class C
(D) Class D
Answer: D
Q. 16 Which one of the following statements is incorrect?
(A) The number of regions corresponds to the cyclomatic complexity.
(B) Cyclometric complexity for a flow graph G is V(G) = N–E+2, where E is the number of edges and N is the number of nodes in the flow graph.
(C) Cyclometric complexity for a flow graph G is V(G) = E–N+2, where E is the number of edges & N is the number of nodes in the flow graph.
(D) Cyclometric complexity for a flow graph G is V(G) = P + 1, where P is the number of predicate nodes contained in the flow graph G.
Answer: B
Q.17 Are we building the right product?
This statement refers to
(A) Verification
(B) Validation
(C) Testing
(D) Software quality assurance
Answer: B
Q.18 The absorption law in Boolean algebra say that
(A) X + X = X
(B) X . X = X
(C) x + x . y = x
(D) None of the above
Answer:C
Q.19 The number of 1’s present in the binary representation of
10 × 256 + 5 × 16 + 5 is
(A) 5 (B) 6
(C) 7 (D) 8
Answer: B
Explanation:
So number of 1's are 6.
So, B is correct option.
Q.20 A latch is constructed using two cross-coupled
(A) AND and OR gates (B) AND gates
(C) NAND and NOR gates (D) NAND gates
Answer: D
