## UGC NET Computer Science Solved Paper -III June 2015

1. For the 8 – bit word 00111001, the check bits stored with it would be 0111. Suppose when the word is read from memory, the check bits are calculated to be 1101. What is the data word that was read from memory ?

(1) 10011001 (2) 00011001 (3) 00111000 (4) 11000110

2. Consider a 32 – bit microprocessor, with a 16 – bit external data bus, driven by an 8 MHz input clock. Assume that this microprocessor has a bus cycle whose minimum duration equals four input clock cycles. What is the maximum data transfer rate for this microprocessor ?

(1) 8×10^{6} bytes/sec (2) 4 x10^{6} bytes/sec

(3) 16×10^{6} bytes/sec (4) 4 x10^{9} bytes/sec

3. The RST 7 instruction in 8085 microprocessor is equivalent to :

(1) CALL 0010 H (2) CALL 0034 H (3) CALL 0038 H (4) CALL 003C H

4. The equivalent hexadecimal notation for octal number 2550276 is :

(1) FADED (2) AEOBE (3) ADOBE (4) ACABE

5. The CPU of a system having 1 MIPS execution rate needs 4 machine cycles on an average for executing an instruction. The fifty percent of the cycles use memory bus. A memory read/ write employs one machine cycle. For execution of the programs, the system utilizes 90 percent of the CPU time. For block data transfer, an IO device is attached to the system while CPU executes the background programs continuously. What is the maximum IO data transfer rate if programmed IO data transfer technique is used ?

(1) 500 Kbytes/sec (2) 2.2 M bytes/sec (3) 125 Kbytes/sec (4) 250 Kbytes/sec

6. The number of flip-flops required to design a modulo – 272 counter is :

(1) 8 (2) 9 (3) 27 (4) 11

7. Let E_{1} and E_{2} be two entities in E-R diagram with simple single valued attributes. R_{1} and R_{2} are two relationships between E_{1} and E_{2} where R_{1} is one – many and R_{2} is many – many. R_{1} and R_{2} do not have any attribute of their own. How many minimum number of tables are required to represent this situation in the Relational Model ?

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

8. The STUDENT information in a university stored in the relation

STUDENT (Name, SEX, Marks, DEPT_Name)

Consider the following SQL Query SELECT DEPT_Name from STUDENT where SEX S ‘M’ group by DEPT_Name having avg (Marks) >SELECT avg (Marks) from STUDENT. It Returns the Name of the Department for which :

(1) The Average marks of Male students is more than the average marks of students in the same Department

(2) The average marks of male students is more than the average marks of students in the University

(3) The average marks of male students is more than the average marks of male students in the University

(4) The average marks of students is more than the average marks of male students in the University

9. Select the ‘False’ statement from the following statements about Normal Forms :

(1) Lossless preserving decomposition into 3NF is always possible

(2) Lossless preserving decomposition into BCNF is always possible

(3) Any Relation with two attributes is in BCNF

(4) BCNF is stronger than 3NF

10. The Relation Vendor Order (V_no, V_ord_no, V_name, Qty_sup, unit_price) is in 2NF because:

(1) Nonkey attribute V_name is dependent on V_no which is part of composite key

(2) Nonkey attribute V_name is dependent on Qty_sup

(3) Key attribute Qty_sup is dependent on primary_key unit price

(4) Key attribute V_ord_no is dependent on primary_key unit price

11. The relation schemas R_{1} and R_{2} form a Lossless join decomposition of R if and only if :

(a) R_{1} ∩R_{2} ↠(R_{1} – R_{2})

(b) R_{1} →R2

(c) R_{1} ∩R_{2}↠(R_{2} – R_{1} )

(d) R_{2}→R_{1} ∩R_{2}

Codes :

(1) (a) and (b) happens (2) (a) and (d) happens

(3) (a) and (c) happens (4) (b) and (c) happens

12. In the indexed scheme of blocks to a file, the maximum possible size of the file depends on :

(1) The number of blocks used for index and the size of index

(2) Size of Blocks and size of Address

(3) Size of index

(4) Size of Block

13. Give the number of principal vanishing point(s) along with their direction for the standard perspective transformation :

(1) Only one in the direction K (2) Two in the directions I and J

(3) Three in the directions I, J and K (4) Only two in the directions J and K

14. Consider a triangle A(0,0), 13(1,1) and C(5,2). The triangle has to be rotated by an angle of 45° about the point P(-1, -1). What shall be the coordinates of the new triangle ?

(1) A’ = ( 1,√ 2 – 1 ) , B’ = ( -1, 2√ 2 – 1 ) and C’ = [3√ 2 – 1, 9/2 √ 2 – 1]

(2) A’ = ( 1,√ 2 – 1 ) , B’ = ( 2√ 2 – 1, -1 ) and C’ = [3√ 2 – 1, 9/2 √ 2 – 1]

(3) A’ = ( -1,√ 2 – 1 ) , B’ = ( -1, 2√ 2 – 1 ) and C’ = [3√ 2 – 1, 9/2 √ 2 – 1]

(4) A’ = (√ 2 – 1, -1 ), B’ = ( -1, 2√ 2 – 1 ) and C’ = [3√ 2 – 1, 9/2 √ 2 – 1]

15. The process of dividing an analog signal into a string of discrete outputs, each of constant amplitude, is called:

(1) Strobing (2) Amplification (3) Conditioning (4) Quantization

16. Which of the following is not a basic primitive of the Graphics Kernel System (GKS) ?

(1) POLYLINE (2) POLYDRAW (3) FILL AREA (4) POLYMARKER

17. Which of the following statement(s) is/are incorrect ?

(a) Mapping the co-ordinates of the points and lines that form the picture into the appropriate co-ordinates on the device or workstation is known as viewing transformation.

(b) The right-handed cartesian co-ordinates system in whose co-ordinates we describe the picture is known as world co-ordinate system.

(c) The co-ordinate system that corresponds to the device or workstation where the image is to be displayed is known as physical device co-ordinate system.

(d) Left – handed co-ordinate system in which the display area of the virtual display device corresponds to the unit (Ixl) square whose lower left-hand corner is at the origin of the co-ordinate system, is known as normalized device co-ordinate system.

Codes :

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

18. Match the following :

List-I List-II

(a) Flood Gun (i) An electron gun designed to flood the entire screen with electrons.

(b) Collector (ii) Partly energised by flooding gun, stores the charge generated by the writing gun.

(c) Ground (iii) Used to discharge the collector.

(d) Phosphorus grains (iv) Used in memory – tube display and similar to those used in standard CRT.

(e) Writing Gun System (v) Used in memory – tube display and basically the same as the electron gun used in a conventional CRT.

Codes :

(a) (b) (c) (d) (e)

(1) (i) (ii) (iii) (iv) (v)

(2) (ii) (iii) (i) (iv) (v)

(3) (iii) (i) (ii) (v) (iv)

(4) (iv) (v) (i) (ii) (iii)

19. Minimal deterministic finite automaton for the language L = {0^{n} | n ≥ 0 , n ≠ 4} will have :

(1) 1 final state among 5 states (2) 4 final states among 5 states

(3) 1 final state among 6 states (4) 5 final states among 6 states

20. The regular expression corresponding to the language L where

L = {x ∈ {0, 1}^{*} | x ends with 1 and does not contain substring 00} is :

(1) (1+01)^{*} (10 + 01) (2) (1+01)^{*} 01

(3) (1+01)^{*} (1 + 01) (4) (10+01)^{*}01

21. The transition function for the language L = {w|n_{a}(w) and n_{b}(w) are both odd} is given by :

δ(q_{0}, a) = q_{1 ; }δ(q_{0}, b) = q_{2}

δ(q_{1}, a) = q_{0 ; }δ(q_{1}, b) = q_{3}

δ(q_{2}, a) = q_{3 ; }δ(q_{2}, b) = q_{0}

δ(q_{3}, a) = q_{2 ; }δ(q_{3}, b) = q_{1}

The initial and final states of the automata are :

(1) q_{0 }and q_{0 }respectively (2) q_{0 }and q_{1 }respectively

(3) q_{0 }and q_{2 }respectively (4) q_{0 }and q_{3 }respectively

22. The clausal form of the disjunctive normal form ¬ A ∨ ¬ B ∨ ¬ C ∨ D is:

(1) A∧B∧C⇒D (2) A∨B∨C∨D⇒true

(3) A∧B∧C∧D⇒true (4) A ∧ B ∧ C ∧ D ⇒ false

23. Which of the following is false for the programming language PROLOG ?

(1) A PROLOG variable can only be assigned to a value once

(2) PROLOG is a strongly typed language

(3) The scope of a variable in PROLOG is a single clause or rule

(4) The scope of a variable in PROLOG is a single query

24. Which one of the following is true ?

(1) The resolvent of two Horn clauses is not a Horn clause

(2) The resolvent of two Horn clauses is a Horn clause

(3) If we resolve a negated goal G against a fact or rule A to get clause C then C has positive literal or non-null goal

(4) If we resolve a negated goal G against a fact or rule A to get clause C then C has positive literal or null goal

25. Which transmission technique guarantees that data packets will be received by the receiver in the same order in which they were sent by the sender ?

(1) Broadcasting (2) Unicasting

(3) Packet switching (4) Circuit switching

26. Which of the following control fields in TCP header is used to specify whether the sender has no more data to transmit ?

(1) FIN (2) RST (3) SYN (4) PSH

27. Which are the two modes of IP security ?

(1) Transport and certificate (2) Transport and tunnel

(3) Certificate and tunnel (4) Preshared and transport

28. A message “COMPUTERNETWORK” encrypted (ignore quotes) using columnar transposition cipher with a key “LAYER”. The encrypted message is :

(1) CTTOEWMROPNRUEK (2) MROUEKCTTPNROEW

(3) OEWPNRCTTUEKMRO (4) UEKPNRMROOEWCTT

29. Suppose a digitized voice channel is made by digitizing 8 kHz bandwidth analog voice signal. It is required to sample the signal at twice the highest frequency (two samples per hertz). What is the bit rate required, if it is assumed that each sample requires 8 bits ?

(1) 32 kbps (2) 64 kbps (3) 128 kbps (4) 256 kbps

30. The maximum payload of a TCP segment is :

(1) 65,535 (2) 65,515 (3) 65,495 (4) 65,475

31. An all-pairs shortest-paths problem is efficiently solved using :

(1) Dijkstra’ algorithm (2) Bellman-Ford algorithm

(3) Kruskal algorithm (4) Floyd-Warshall algorithm

32. The travelling salesman problem can be solved in :

(1) Polynomial time using dynamic programming algorithm

(2) Polynomial time using branch-and-bound algorithm

(3) Exponential time using dynamic programming algorithm or branch-and-bound algorithm

(4) Polynomial time using backtracking algorithm

33. Which of the following is asymptotically smaller ?

(1) lg(lg*n) (2) lg*(lgn) (3) lg(n!) (4) lg*(n!)

34. Consider a hash table of size m = 100 and the hash function h(k) = floor (m(kA mod 1)) for A = (√ 2 -1) / 2 = 0.618033. Compute the location to which the key k = 123456 is placed in hash table.

(1) 77 (2) 82 (3) 88 (4) 89

35. Let ƒ(n) and g (n) be asymptotically non-negative functions. Which of the following is correct ?

(1) θ(ƒ(n)*g(n)) = min(ƒ(n), g(n)) (2) θ(ƒ(n)*g(n)) = max(ƒ(n), g(n))

(3) θ(ƒ(n)+g(n)) = min(ƒ(n), g(n)) (4) θ(ƒ(n)+g(n)) = max(ƒ(n), g(n))

*1*

*2*