## UGC NET Computer Science Solved Paper III Jan 2017

1. Which of the following is an interrupt according to temporal relationship with system clock ?

(1) Maskable interrupt (2) Periodic interrupt

(3) Division by zero (4) Synchronous interrupt

2. Which of the following is incorrect for virtual memory ?

(1) Large programs can be written

(2) More I/O is required

(3) More addressable memory available

(4) Faster and easy swapping of process

3. The general configuration of the microprogrammed control unit is given below :

What are blocks B and C in the diagram respectively ?

(1) Block address register and cache memory

(2) Control address register and control memory

(3) Branch register and cache memory

(4) Control address register and random access memory

4. Match the following :

**Addressing Mode ** **Location of operand**

a. Implied i. Registers which are in CPU

b. Immediate ii. Register specifies the address of the operand.

c. Register iii. Specified in the register

d. Register Indirect iv. Specified implicitly in the definition of instruction

Codes :

a b c d

(1) iv iii i ii

(2) iv i iii ii

(3) iv ii i iii

(4) iv iii ii i

5. In 8085 microprocessor, the digit 5 indicates that the microprocessor needs

(1) –5 volts, +5 volts supply (2) +5 volts supply only

(3) –5 volts supply only (4) 5 MHz clock

6. In 8085, which of the following performs : load register pair immediate operation ?

(1) LDAX rp (2) LHLD addr (3) LXI rp, data (4) INX rp

7. Consider following schedules involving two transactions :

S1 : r1(X); r1(Y); r2(X); r2(Y); w2(Y); w1(X)

S2 : r1(X); r2(X); r2(Y); w2(Y); r1(Y); w1(X)

Which of the following statement is true ?

(1) Both S1 and S2 are conflict serializable.

(2) S1 is conflict serializable and S2 is not conflict serializable.

(3) S1 is not conflict serializable and S2 is conflict serializable.

(4) Both S1 and S2 are not conflict serializable.

8. Which one is correct w.r.t. RDBMS ?

(1) primary key ⊆ super key ⊆ candidate key

(2) primary key ⊆ candidate key ⊆ super key

(3) super key ⊆ candidate key ⊆ primary key

(4) super key ⊆ primary key ⊆ candidate key

9. Let pk(R) denotes primary key of relation R. A many-to-one relationship that exists between two relations R1 and R2 can be expressed as follows :

(1) pk(R2) → pk(R1) (2) pk(R1) → pk(R2)

(3) pk(R2) → R1 ∩ R2 (4) pk(R1) → R1 ∩ R2

10. For a database relation R(A, B, C, D) where the domains of A, B, C and D include only atomic values, only the following functional dependencies and those that can be inferred from them are :

A → C

B → D

The relation R is in _______.

(1) First normal form but not in second normal form.

(2) Both in first normal form as well as in second normal form.

(3) Second normal form but not in third normal form.

(4) Both in second normal form as well as in third normal form.

11. Consider the following relation :

Works (emp_name, company_name, salary)

Here, emp_name is primary key.

Consider the following SQL query

Select emp_name

From works T

where salary > (select avg (salary)

from works S

where T.company _ name = S.company _ name)

The above query is for following :

(1) Find the highest paid employee who earns more than the average salary of all employees of his company.

(2) Find the highest paid employee who earns more than the average salary of all the employees of all the companies.

(3) Find all employees who earn more than the average salary of all employees of all the companies.

(4) Find all employees who earn more than the average salary of all employees of their company.

12. If following sequence of keys are inserted in a B+ tree with K(=3) pointers :

8, 5, 1, 7, 3, 12, 9, 6

Which of the following shall be correct B+ tree ?

Ans: 1

13. Which of the following statement(s) is/are correct ?

(1) Persistence is the term used to describe the duration of phosphorescence.

(2) The control electrode is used to turn the electron beam on and off.

(3) The electron gun creates a source of electrons which are focussed into a narrow beam directed at the face of CRT.

(4) All of the above

14. A segment is any object described by GKS commands and data that start with CREATE SEGMENT and Terminates with CLOSE SEGMENT command. What functions can be performed on these segments ?

(1) Translation and Rotation

(2) Panning and Zooming

(3) Scaling and Shearing

(4) Translation, Rotation, Panning and Zooming

15. Match the following :

a. Glass i. Contains liquid crystal and serves as a bonding surface for a conductive coating.

b. Conductive coating ii. Acts as a conductor so that a voltage can be applied across the liquid crystal.

c. Liquid crystal iii. A substance which will polarize light when a voltage is applied to it.

d. Polarized film iv. A transparent sheet that polarizes light.

Codes :

a b c d

(1) i ii iii iv

(2) i iii ii iv

(3) iv iii ii i

(4) iv ii i iii

16. Below are the few steps given for scan-converting a circle using Bresenham’s Algorithm.

Which of the given steps is not correct ?

(1) Compute d = 3 – 2r (where r is radius)

(2) Stop if x > y

(3) If d < 0, then d = 4x + 6 and x = x + 1

(4) If d ≥ 0, then d = 4 ∗ (x – y) + 10, x = x + 1 and y = y + 1

17. Which of the following is/are side effects of scan conversion ?

a. Aliasing

b. Unequal intensity of diagonal lines

c. Overstriking in photographic applications

d. Local or Global aliasing

(1) a and b (2) a, b and c (3) a, c and d (4) a, b, c and d

18. Consider a line AB with A = (0, 0) and B = (8, 4). Apply a simple DDA algorithm and compute the first four plots on this line.

(1) [(0, 0), (1, 1), (2, 1), (3, 2)] (2) [(0, 0), (1, 1.5), (2, 2), (3, 3)]

(3) [(0, 0), (1, 1), (2, 2.5), (3, 3)] (4) [(0, 0), (1, 2), (2, 2), (3, 2)]

19. Which of the following are not regular ?

(A) Strings of even number of a’s.

(B) Strings of a’s, whose length is a prime number.

(C) Set of all palindromes made up of a’s and b’s.

(D) Strings of a’s whose length is a perfect square.

(1) (A) and (B) only (2) (A), (B) and (C) only

(3) (B), (C) and (D) only (4) (B) and (D) only

20. Consider the languages L1 = φ and L2 = {1}. Which one of the following represents

L*1 ∪ L*2 L*1 ?

(1) {∈} (2) {∈, 1} (3) φ (4) 1*

21. Given the following statements :

(A) A class of languages that is closed under union and complementation has to be closed under intersection.

(B) A class of languages that is closed under union and intersection has to be closed under complementation.

Which of the following options is correct ?

(1) Both (A) and (B) are false.

(2) Both (A) and (B) are true.

(3) (A) is true, (B) is false.

(4) (A) is false, (B) is true.

22. Let G = (V, T, S, P) be a context-free grammar such that every one of its productions is of the form A → v, with |v| = K > 1. The derivation tree for any W ∈ L(G) has a height h such that

Ans:4

23. Given the following two languages :

L1 = {a^{n} b^{n} | n ≥ 0, n ≠ 100}

L2 = {w ∈ {a, b, c}*| n_{a}(w) = n_{b}(w) = n_{c}(w)}

Which of the following options is correct ?

(1) Both L1 and L2 are not context free language

(2) Both L1 and L2 are context free language.

(3) L1 is context free language, L2 is not context free language.

(4) L1 is not context free language, L2 is context free language.

24. A recursive function h, is defined as follows :

h(m) = k, if m = 0

= 1, if m = 1

= 2 h(m – 1) + 4h(m – 2), if m ≥ 2

If the value of h(4) is 88 then the value of k is :

(1) 0 (2) 1 (3) 2 (4) –1

25. Suppose there are n stations in a slotted LAN. Each station attempts to transmit with a probability P in each time slot. The probability that only one station transmits in a given slot is _______.

(1) nP(1 – P)^{n – 1} (2) nP

(3) P(1 – P)^{n – 1} (4) n^{p}(1 – P)^{n – 1}

26. Station A uses 32 byte packets to transmit messages to station B using sliding window protocol. The round trip delay between A and B is 40 milliseconds and the bottleneck bandwidth on the path between A and B is 64 kbps. The optimal window size of A is ________.

(1) 20 (2) 10 (3) 30 (4) 40

27. Let G(x) be generator polynomial used for CRC checking. The condition that should be satisfied by G(x) to correct odd numbered error bits, will be :

(1) (1 + x) is factor of G(x) (2) (1 – x) is factor of G(x)

(3) (1 + x2) is factor of G(x) (4) x is factor of G(x)

28. In a packet switching network, if the message size is 48 bytes and each packet contains a header of 3 bytes. If 24 packets are required to transmit the message, the packet size is ________.

(1) 2 bytes (2) 1 byte (3) 4 bytes (4) 5 bytes

29. In RSA public key cryptosystem suppose n = p ∗ q where p and q are primes. (e, n) and (d, n) are public and private keys respectively. Let M be an integer such that o < M < n and φ(n) = (p – 1) (q – 1).

Which of the following equations represent RSA public key cryptosystem ?

I. C ≡ M^{e} (mod n) II. ed ≡ 1(mod n)

M ≡ (C)^{d} (mod n)

III. ed ≡ 1(mod φ(n)) IV. C ≡ M^{e}(mod φ(n))

M ≡ C^{d}(mod φ(n))

Codes :

(1) I and II (2) I and III (3) II and III (4) I and IV

30. A node X on a 10 Mbps network is regulated by a token bucket. The token bucket is filled at a rate of 2 Mbps. Token bucket is initially filled with 16 megabits. The maximum duration taken by X to transmit at full rate of 10 Mbps is _________ secs.

(1) 1 (2) 2 (3) 3 (4) 4

31. The asymptotic upper bound solution of the recurrence relation given by

(1) O(n^{2}) (2) O(n lg n) (3) O(n lg lg n) (4) O(lg lg n)

32. Any decision tree that sorts n elements has height ________.

(1) Ω(lg n) (2) Ω(n) (3) Ω(n lg n) (4) Ω(n^{2})

33. Red-black trees are one of many search tree schemes that are “balanced” in order to guarantee that basic dynamic-set operations take ________ time in the worst case.

(1) O(1) (2) O(lg n) (3) O(n) (4) O(n lg n)

34. The minimum number of scalar multiplication required, for parenthesization of a matrixchain product whose sequence of dimensions for four matrices is <5, 10, 3, 12, 5> is

(1) 630 (2) 580 (3) 480 (4) 405

35. Dijkstra’s algorithm is based on

(1) Divide and conquer paradigm (2) Dynamic programming

(3) Greedy Approach (4) Backtracking paradigm

36. Match the following with respect to algorithm paradigms :

List – I List – II

a. Merge sort i. Dynamic programming

b. Huffman coding ii. Greedy approach

c. Optimal polygon triangulation iii. Divide and conquer

d. Subset sum problem iv. Back tracking

Codes :

a b c d

(1) iii i ii iv

(2) ii i iv iii

(3) ii i iii iv

(4) iii ii i iv

37. Abstraction and encapsulation are fundamental principles that underlie the object oriented approach to software development. What can you say about the following two statements ?

I. Abstraction allows us to focus on what something does without considering the complexities of how it works.

II. Encapsulation allows us to consider complex ideas while ignoring irrelevant detail that would confuse us.

(1) Neither I nor II is correct.

(2) Both I and II are correct.

(3) Only II is correct.

(4) Only I is correct.

38. Given the array of integers ‘array’ shown below :

13 7 27 2 18 33 9 11 22 8

What is the output of the following JAVA statements ?

int [ ] p = new int [10];

int [ ] q = new int [10];

for (int k = 0; k < 10; k ++)

p[k] = array [k];

q = p;

p[4] = 20;

System.out.println(array [4] + “:” + q[4]);

(1) 20 : 20 (2) 18 : 18 (3) 18 : 20 (4) 20 : 18

39. Consider the following JAVA program :

public class First {

public static int CBSE (int x) {

if (x < 100) x = CBSE (x + 10);

return (x – 1);

}

public static void main (String[] args){

System.out.print(First.CBSE(60));

}

}

What does this program print ?

(1) 59 (2) 95 (3) 69 (4) 99

40. Which of the following statement(s) with regard to an abstract class in JAVA is/are TRUE ?

I. An abstract class is one that is not used to create objects.

II. An abstract class is designed only to act as a base class to be inherited by other classes.

(1) Only I (2) Only II

(3) Neither I nor II (4) Both I and II

*1*

*2*