# UGC NET Computer Science Solved Paper II JUNE 2007

1. The following deterministic finite automata recognizes:

(A) Set of all strings containing ‘ab’

(B) Set of all strings containing ‘aab’

(C) Set of all strings ending in ‘abab’

(D) None of the above

1. Depth ion travels of the following directed graph is:

(A) ABCDEF     (B) ABDEFC

(C) ACEBDF    (D) None of the above

1. The maximum number of nodes in a binary tree of depth 10 is:

(A) 1024                        (B) 210-1

(C) 1000                        (D) None of the above

1. The regular expression given below describes:

r=(1+01)*(0+λ)

(A) Set of all string not containing ‘11’

(B) Set of all string not containing ‘00’

(C) Set of all string containing ‘01’

(D) Set of all string ending in ‘0’

1. Which of the following language is regular?

(A) L={anbn|n≥1}

(B) L={anbmcndm|n,m≥1}

(C) L={anbm|n,m≥1}

(D) L={anbmcn|n,m≥1}

1. 2’s complement of -100 is:

(A) 00011100               (B) 10011101

(C) 10011100               (D) 11100100

1. Which of the following expression remove hazard form: xy+zx’ ?

(A) xy+zx’          (B) xy+zx’

(C) xy+zx’+yz    (D) xy+zx’+wz

1. How many 1’s are present in the binary representation of 15×256+5×16+3:

(A) 8       (B) 9

(C) 10     (D) 11

1. If A⊕B=C, then:

(A) A⊕C=B                   (B) B⊕C=A

(C) A⊕B⊕C=1                        (D) A⊕B⊕C=0

1. What is the maximum counting speed of a 4-bit binary counter which is composed of Flip-Flop with a propagation delay of 25ns?

(A) 1MHz           (B) 10MHz

(C) 100MHz      (D) 4MHz

1. The following loop in ‘C’:

int i=0;

While(i++<0)i–;

(A) will terminate

(B) will go into an infinite loop

(C) will give compilation error

(D) will never be executed

1. In case of right shift bitwise operator in ‘C’ language, after shifting n bits, the left most n bits:

(A) are always filled with zeroes

(B) are always filled with ones

(C) are filled with zeroes or ones and is machine dependent

(D) none of the above

1. What keyword in class specification helps to hide data:

(A) Public          (B) Private

(C) Static           (D) Void

1. What is the output of the following ‘C’ program?

main()

{printf(“%x”,-1>>4);}

(A) ffff                (B) 0fff

(C) 0000                        (D) fff0

Explanation

1. Runtime polymorphism can be achieved by:

(A) Accessing virtual function through the pointer of the base class

(B) Accessing virtual function through the object

(C) The derived class

(D) None of these

1. Which of the following statements is wrong?

(A) 2-phase Locking Protocols suffer from deadlocks

(B) Time-Stamp Protocols suffer from more aborts

(C) Time-Stamp Protocols suffer from cascading roll back where as 2-Phase locking Protocol do not

(D) None of these

1. A recursive foreign key is a:

(A) references a relation

(B) references a table

(C) references its own relation

(D) references a foreign key

1. A sub class having more than one super class is called:

(A) Category                 (B) Classification

(C) Combination          (D) Partial Participation

1. A relation R={A,B,C,D,E,F} is given with following set of functional dependencies:

F={A→B,AD→C,B→F,A→E}. Which of the following is Candidate Key?

(A) A                   (B) AC

(C) AD               (D) None of these

1. Which statement is false regarding data independence?

(A) Hierarchical data model suffers from data Independence

(B) Network model suffers from data Independence

(C) Relational model suffers only from logical data Independence

(D) Relational model suffers only from physical data Independence

1. The time required to find shortest path in a graph with n vertices and e edges is:

(A) O(e)              (B) O(n)

(C) O(e2)            (D) O(n2)

1. Pre order is also known as:

(A) Depth first order                 (B) Breadth first order

(C) Topological order              (D) Linear order

1. The equivalent post fix express for d/(e+f) + b*c is:

(A) defbc/++                  (B) def+/bc+*

(C) def+/bc*+                (D) None of these

1. Which algorithm has same average, worst case and best case time?

(A) Binary search        (B) Maximum of n numbers

(C) Quick sort               (D) Fibonacci search

1. Application of data structure in queue is:

(A) Level wise printing of tree

(B) Implementation of priority queues

(C) Function call implementation

(D) Depth first search in a graph

1. In case of Bus/Tree topology signal balancing issue is overcome by:

(A) Strong Transmitter                        (B) Polling

(C) Segmentation                    (D) Modulation

1. Which of the following techniques are used to control data flow?           1. Windowing   2. Routing     3. RPCs         4. Buffering

(A) 1, 4               (B) 2, 3, 4

(C) 1, 3, 4          (D) 1, 2, 3, 4

1. TDM is …………….

(A) A primary/secondary type protocol

(B) A peer/peer protocol

(C) A Non-priority peer/peer protocol

(D) A priority type protocol

1. What services does the Internet Layer provide?
2. Quality of service                2. Routing
4. Framing bits

(A) 1, 2, 3                       (B) 2, 3, 4

(C) 1, 3, 4, 5                  (D) 2, 3, 4, 5

1. Which of the following protocols is used to prevent looping?

(A) OSPF                      (B) Spanning tree

(C) SRB                         (D) Fragment free switching

1. The parsing technique that avoids back tracking is:

(A) Top-down parsing

(B) Recursive-descent parsing

(C) Predictive

(D) Syntax tree

1. A Top-down Parse generates:

(A) Right-most derivation

(B) Right-most derivation in reverse

(C) Left-most derivation

(D) Left-most derivation in reverse

(C) Reallocation          (D) Both (A) and (B)

1. Symbol table can be used for:

(A) Checking type compatibility

(B) Suppressing duplication of error message

(C) Storage allocation

(D) All of these above

1. Moving process from main memory to disk is called:

(A) Caching                  (B) Termination

(C) Swapping               (D) Interruption

1. Part of a program where the shared memory is accessed and which should be executed indivisibly, is called:

(A) Semaphores                      (B) Directory

(C) Critical Section                  (D) Mutual exclusion

1. Windows is a ……………… operating system.

(A) Non pre-emptive                (B) Pre-emptive

(C) Multi-user                           (D) Real time

1. The “nice” command is used in Unix:

(A) to decrease the priority of a process

(B) to increase the priority of a process

(C) to get the highest priority

(D) nothing to do with the priorities

Explanation:

For Increase or decrease the priority of a job/Process we use Nice command, and its range -19 to 20.

If we need to increase the priority then we needs to decrease the priority number

If we need to decrease the priority then we needs to increase the priority number

Ex:- Nice -n 10 <cmd>

1. Which page replacement policy suffers from Belady’s anomaly?

(A) LRU             (B) LFU

(C) FIFO            (D) OPTIMAL

1. Cache memory is:

(A) High Speed Register        (B) Low-Speed RAM

(C) Non-Volatile RAM             (D) High-Speed RAM

1. Which of the following combination is preferred with respect to cohesion and coupling?

(A) low and low                        (B) low and high

(C) high and low          (D) high and high

1. Difference between flow-chart and data-flow diagram is:

(A) there is no difference

(B) usage in high level design and low level design

(C) control flow and data flow

(D) used in application programs and system programs

1. Match the following:

(a) Unit test                   (i) Requirements

(b) System test             (ii) Design

(c) Validation test         (iii) Code

(d) Integration test       (iv) System Engineering

Which of the following is true?

(a)     (b)      (c)    (d)

(A)   (ii)     (iii)      (iv)    (i)

(B)   (i)      (ii)       (iv)   (iii)

(C)   (iii)    (iv)      (i)     (ii)

(D)   None of the above

1. Problems with waterfall model are:     1. Real projects rarely follow this model proposes.                                      2. It is often difficult for the customer.                                3.Working model is available only in the end.                                                4. Developers are delayed unnecessarily

Which of the following is true?

(A) 1 and 4 only           (B) 2 and 3 only

(C) 1, 2 and 3 only       (D) 1, 2, 3 and 4

1. Which one of the following is a object-oriented approaches:

(A) The Booch method

(B) The Rumbaugh method

(C) The Coad and Yomdon method

(D) All of the above

1. Which technical concept sets cellular apart from all preceding mobile/radio systems?

(A) FM-Transmission

(B) Duplex Functionality

(C) Frequency Reuse

(D) TDMA Technology

1. Wireless interconnections to the PSTN are also known as:

(A) Localities                (B) CLECs

(C) POPs                       (D) IXCs

1. Dimensional modeling  in Data mining refers to:

(A) view and interrogate data

(B) define structures and store data

(C) retrieve information only

(D) none of these

1. The U-NII(Unlicensed National Information Infrastructure) band operates at the …………. frequency.

(A) 2.4 GHz       (B) 33 MHz

(C) 5 GHz          (D) 16 GHz