# UGC NET Computer Science Solved Paper II JUNE 2008

UGC NET ALL QUESTIONS SOLVED WITH EXPLANATION PAPER 2 @ RS150 AND PAPER 3 @ RS 250. and BOTH @RS 350 ONLYCALL 94178-24400

1. Which of the following does not define a tree?

(A)  A tree is a connected acyclic graph.

(B)  A tree is a connected graph with n-1 edges where ’n’ is the number of vertices in the graph.

(C)  A tree is an acyclic graph with n-1 edges where ’n’ is the number of vertices in the graph.

(D) A tree is a graph with no cycles.

1. The complexity of Kruskal’s minimum spanning tree algorithm on a graph with ‘n’ nodes and ‘e’ edges is :

(A) O(n)             (B) O(n log n)

(C) O(e log n)   (D) O(e)

1. If a code is t-error correcting, the minimum Hamming distance is equal to:

(A) 2t+1              (B) 2t

(C) 2t-1              (D) t-1

1. The set of positive integers under the operation of ordinary multiplication is:

(A) not a monoid          (B) not a group

(C) a group                   (D) an Abelian group

1. In a set of 8 positive integers, there always exists a pair of numbers having the same remainder when divided by:

5.(A) 7                   (B) 11

(C) 13                 (D) 15

According to pigeonhole principle

7 can have 7 remainder values i.e 0,1,2,3,4,5,6

so in 8 integers atleast 1 remainder value will occur twice

1. An example of a tautology is:

(A) x v y             (B) x v (~y)

(C) x v (~x)        (D) (x=>y)˄(x<=y)

Explanation:

1. Among the logic families RTL, TTL, ECL and CMOS, the fastest family is:

(A) ECL             (B) CMOS

(C) TTL              (D) RTL

1. The octal equivalent of the hexadecimal number FF is:

(A) 100               (B) 150

(C) 377              (D) 737

Explanation:

1. The characteristic equation of a T flip flop is given by:

(A) QN+1=TQN                (B) QN+1=T+QN

(C) QN+1=T⊕QN           (D) QN+1=T’+QN

1. The idempotent law in Boolean algebra says that:

(A) ~(~x)=x        (B) x+x=x

(C) x+xy=x         (D) x(x+y)=x

1. What is the effect of the following C code?

for(int i=1; i≤5; i=i+½)

printf(“%d,”,i);

(A) It prints 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, and stops

(B) It prints 1, 2, 3, 4, 5, and stops

(C) It prints 1, 2, 3, 4, 5, and repeats forever

(D) It prints 1, 1, 1, 1, 1, and repeats forever

Explanation:

1. Consider the following declaration in C:

char a[];

char *p;

Which of the following statement is not a valid statement?

(A) p=a;              (B) p=a+2;

(C) a=p;             (D) p=&a[2];

Explanation:

1. Consider the following C code:

{ int a=5, b=9;

float r;

r=b/a; }

What is the value of r ?

(A) 1.8    (B) 1.0

(C) 2.0    (D) 0.0

(A) a function is used to implement lots of tasks at the same time.

(B) a function is called too many number of times by another function.

(C) a function provides common interface to the user to carry out possibly different functions in each call.

(D) a function is computationally too expensive for the system to handle.

1. Which of the following is true?

(A) A “static” member of a class cannot be inherited by its derived class.

(B) A “static” member of a class can be initialized only within the class it is a member of.

(C) A “static” member of a class can be initialized before an object of that class is created.

(D) Since “static” member of a class is actually a global element, it does not require a class/object qualifier to access it independently of class/object.

1. A superkey for an entity consists of:

(A) one attribute only

(B) at least two attributes

(C) at most two attributes

(D) one or more attributes

1. Which of the following set of keywords constitutes a mapping in SQL?

(A) SELECT, FROM, TABLE

(B) SELECT, FROM, WHERE

(C) CONNECT, TABLE, CREATE

(D) SELECT, TABLE, INSERT

1. If a relation is in 2NF then:

(A) every candidate key is a primary key

(B) every non-prime attribute is fully functionally dependent on each relation key

(C) every attribute is functionally independent

(D) every relational key is a primary key

1. Which of the following is true?

(A) A relation in 3NF is always in BCNF

(B) A relation in BCNF is always in 3NF

(C) BCNF and 3NF are totally different

(D) A relation in BCNF is in 2NF but not in 3NF

1. Consider the query : SELECT student_name FROM student_data WHERE rollno (SELECT rollno FROM student_marks WHERE SEM1_MARK=SEM2_MARK);

Which of the following is true ?

(A) It gives the name of the student whose marks in semester 1 and semester 2 are same.

(B) It gives all the names and roll nos  of those students whose marks in semester 1 and semester 2 are same.

(C) It gives the names of all the students whose marks in semester 1 and semester 2 are same.

(D) It gives roll numbers of all students whose marks in semester 1 and semester 2 are same.

1. Which of the following data structures is most efficient in terms of both space and time to reverse a string of characters?

(C) Array                        (D) Tree

1. Which of the following can be the sequence of nodes examined in a binary search tree while searching for key 98?

(A) 100, 50, 75, 60, 98

(B) 100, 120, 90, 95, 98

(C) 200, 70, 100, 95, 98

(D) 75, 150, 90, 80, 98

EXPLANATION:

1. Which of the following is true for a sorted list with ‘n’ elements?

(A) Insertion in a sorted array takes constant time.

(B) Insertion in a sorted linear linked list takes constant time.

(C) Searching for a key in a sorted array can be done in O(log n) time.

(D) Searching for a key in a sorted linear linked list can be done in O(log n) time.

1. Files that are related to input/output and are used to model serial I/O devices such as terminals, printers and networks are called :

(A) regular files                        (B) character special files

(C) directories               (D) block special files

1. An example of a possible file attribute is:

(A) minimum size        (B) permanent flag

(C) archive flag                        (D) EBCDIC flag

1. The ATM cells are ……………. bytes long.

(A) 48     (B) 53             (C) 64             (D) 69

1. For slotted ALOHA, the maximum channel utilization is :

(A) 100%           (B) 50%

(C) 36%             (D) 18%

1. For a channel of 3 KHz bandwidth and signal to noise ratio of 30 dB, the maximum data rate is:

(A) 3000 bps                 (B) 6000 bps

(C) 15000 bps              (D) 30000 bps

1. An example of a public key encryption algorithm is:

(A) Caesar cipher algorithm

(B) DES algorithm

(C) AES algorithm

(D) Knapsack algorithm

1. With reference to hierarchical routing, the optimum number of levels for an m router subnet is:

(A) m2                (B) m

(C) ln m             (D) √m

1. Assembler program is:

(A) dependent on the operating system

(B) dependent on the compiler

(C) dependent on the hardware

(D) independent of the hardware

1. In the indirect addressing scheme, the second part of an instruction contains:

(A) the operand in decimal form

(B) the address of the location where the value of the operand is stored

(C) the address of the location where the address of the operand is stored

(D) the operand in an encoded form

1. At the end of parsing,

(A) tokens are identified.

(B) set of instructions are identified.

(C) the syntactic groups are identified.

(D) machine instructions are identified.

1. Dead-code elimination in machine code optimization refers to:

(A) removal of all labels.

(B) removal of values that never get used.

(C) removal of function which are not involved.

(D) removal of a module after its use.

1. A parse tree is an annotated parse tree if:

(A) it shows attribute values at each node.

(B) there are no inherited attributes.

(C) it has synthesized nodes as terminal nodes.

(D) every non-terminal nodes is an inherited attribute.

1. An example of a non-preemptive CPU scheduling algorithm is:

(A) Shortest job first scheduling.

(B) Round robin scheduling.

(C) Priority scheduling.

(D) Fair share scheduling.

1. There are ‘n’ processes in memory. A process spends a fraction ‘p’ of its time waiting for I/O to complete. The CPU utilization is given by:

(A) pn                   (B) 1-pn

(C) (1-p)n               (D) 1-np

1. An example of a memory management system call in UNIX is:

(A) fork.              (B) mmap.

(C) sigaction.    (D)execve.

1. With 64 bit virtual addresses, a 4KB page and 256 MB of RAM, an inverted page table requires:

(A) 8192 entries.          (B) 16384 entries.

(C) 32768 entries.        (D) 65536 entries.

1. A computer has 6 tape drives with ‘n’ processes competing for them. Each process may need two drives. For which values of ‘n’ is the system deadlock free ?

(A) 1       (B) 2    (C) 3   (D) 6

1. Water fall model for software development is:

(A) a top down approach.

(B) a bottom up approach.

(C) a sequential approach.

(D) a consequential approach.

1. In software development, value adjustment factors include the following among others:

(A) the criticality of the performance and reusability of the code.

(B) number of lines of code in the software.

(C) number of technical manpower and hardware costs.

(D) time period available and the level of user friendliness.

1. While designing the user interface, one should:

(A) use as many short cuts as possible.

(B) use as many defaults as possible.

(C) use as many visual layouts as possible.

(D) reduce the demand on short-term memory.

1. In software cost estimation, base estimation is related to:

(A) cost of similar projects already completed.

(B) cost of the base model of the present project.

(C) cost of the project with the base minimum profit.

(D) cost of the project under ideal situations.

1. In clean room software engineering:

(A) only eco-friendly hardware is used.

(B) only hired facilities are used for development.

(C) correctness of the code is verified before testing.

(D) implementation is done only after ensuring correctness.

1. Amdahl’s law states that the maximum speedup S achievable by a parallel computer with ‘p’ processors is given by:

(A) S≤f+(1-f)/p              (B) S≤f/p+(1-f)

(C) S≤1/[f+(1-f)/p]         (D) S≤1/[1-f+f/p]

1. With reference to cluster analysis in data mining, a distance measure that is NOT used is:

(A) Euclidean distance.          (B) Manhattan distance.

(C) Chebychev’s distance.    (D) Lee distance.

1. In a mobile communication system, a geographic region is divided into cells. For each frequency set, there is a buffer …………… wide where that frequency is not used.

(A) one-cell       (B) two-cells

(C) three-cells  (D) four-cells

1. Identify the incorrect statement:

(A) The overall strategy drives the e-commerce data warehousing strategy.

(B) Data warehousing in an e-commerce environment should be done in a classical manner.

(C) E-commerce opens up an entirely new world of web servers.

(D) E-commerce security threats can be grouped into three major categories.

1. Identify the incorrect statement:

(A) The ATM adaptation layer is not service dependent.

(B) Logical connections in ATM are referred to as virtual channel connections.

(C) ATM is a streamlined protocol with minimal error and flow control capabilities.

(D) ATM is also known as cell relay.