UGC NET Computer Science Solved Paper II DECEMBER 2008

1. The channel capacity of a band-limited Gaussian channel is given by:

(A) B log2(2+S/N)         (B) B log2(1+S/N)

(C) B log10(1+S/N)       (D) B loge(1+S/N)

1. The graph K3,4 has:

(A) 3 edges       (B) 4 edges

(C) 7 edges       (D) 12 edges

1. The total number of spanning trees that can be drawn using five labeled vertices is:

(A) 125               (B) 64

(C) 36                 (D) 16

1. Extremely low power dissipation and low cost per gate can be achieved in:

(A) MOS ICs     (B) C MOS ICs

(C) TTL ICs       (D) ECL ICs

1. An example of a universal building block is:

(A) EX-OR gate            (B) AND gate

(C) OR gate                  (D) NOR gate

1. An example of a layer that is absent in broadcast networks is:

(A) Physical layer        (B) Presentation layer

(C) Network layer         (D) Application layer

1. The ATM cell is:

(A) 48 bytes long         (B) 53 bytes long

(C) 64 bytes long         (D) 69 bytes long

1. Four jobs J1, J2, J3 and J4 are waiting to be run. Their expected run times are 9, 6, 3 and 5 respectively. In order to minimize average response time, the jobs should be run in the order:

(A) J1 J2 J3 J4                (B) J4 J3 J2 J1

(C) J3 J4 J1 J2                (D) J3 J4 J2 J1

1. Suppose it takes 100 ns to access page table and 20 ns to access associative memory. If the average access time is 28 ns, the corresponding hit rate is:

(A) 100 percent                        (B) 90 percent

(C) 80 percent              (D) 70 percent

1. Transmission of N signals, each band limited to fm Hz by TDM, requires a minimum band-width of:

(A) fm                  (B) 2 fm

(C) N fm              (D) 2N fm

1. If a code is ‘t’ error detecting, the minimum hamming distance should be equal to:

(A) t-1                 (B) t

(C) t+1                (D) 2t+1

1. A relation R in {1,2,3,4,5,6} is given by {(1,2),(2,3),(3,4),(4,4),(4,5)}. This relation is:

(A) reflexive

(B) symmetric

(C) transitive

(D) not reflexive, not symmetric and not transitive

1. The dual of the switching function x+yz is:

(A) x+yz             (B) x’+y’z’

(C) x(y+z)          (D) x’(y’+z’)

1. The characteristic equation of D flip-flop is:

(A) Q=1              (B) Q=0

(C) Q=D’            (D) Q=D

1. If 4 input multiplexers drive a 4 input multiplexer, we get a:

(A) 16 input MUX         (B) 8 input MUX

(C) 4 input MUX           (D) 2 input MUX

1. The throughput of slotted ALOHA is given by:

(A) S=G             (B) S=GeG

(C) S=Ge-G        (D) S=eG

1. Congestion control is done by:

(A) Network layer                     (B) Physical layer

(C) Presentation layer                        (D) Application layer

1. Assertion (A): Twisted pairs are widely used as transmission medium.

Reasoning (R): Twisted pairs have adequate performance and low cost.

(A) Both (A) and (R) are true and (R) is the correct explanation for (A)

(B) Both (A) and (R) are true but (R) is not the correct explanation

(C) (A) is true but (R) is false

(D) (A) is false but (R) is true

1. An example of a non-adaptive routing algorithm is:

(A) Shortest path routing

(B) Centralised routing

(C) Baran’s hot potato routing

(D) Baran’s backward learning algorithm

1. IP address in B class is given by:

(A) 125.123.123.2        (B) 191.023.21.54

(C) 192.128.32.56        (D) 10.14.12.34

1. N processes are waiting for I/O. A process spends a fraction p of its time in I/O wait state. The CPU utilization is given by:

(A) 1-p-N             (B) 1-pN

(C) pN                 (D) p-N

1. If holes are half as large as processes, the fraction of memory wasted in holes is:

(A) 2/3                (B) 1/2

(C) 1/3                (D) 1/5

1. An example of a non pre-emptive scheduling algorithm is:

(A) Round Robin

(B) Priority Scheduling

(C) Shortest job first

(D) 2 level scheduling

1. An example of distributed OS is:

(A) Amoeba      (B) UNIX

(C) MS-DOS     (D) MULTICS

1. Which one of the following describes correctly a static variable?

(A) It cannot be initialized

(B) It is initialized once at the commencement of execution and cannot be changed at run time

(C) It retains its value during the life of the program

(D) None of the above

1. The output of the program code

main()

{

int x=0;

while (x<=10)

for(;;)

if(++x%10==0)

break;

printf(“x=%d”,x);

}

is :

(A) x=1               (B) compilation error

(C) x=20                        (D) none of the above

1. A copy constructor is invoked when:

(A) a function returns by value

(B) an argument is passed by value

(C) a function returns by reference

(D) none of the above

1. When a language has the capability to produce new data types, it is said to be:

(A) extensible               (B) encapsulated

(C) overloaded             (D) none of the above

1. How many constructors can a class have?

(A) zero              (B) 1

(C) 2                   (D) any number

1. An entity has:

(i) a set of properties

(ii) a set of properties and values for all the properties

(iii) a set of properties and the values for some set of properties may non-uniquely identify an entity

(iv) a set of properties and the values for some set of properties may uniquely identify an entity

Which of the above are valid?

(A) (i) only         (B) (ii) only

(C) (iii) only       (D) (iv) only

1. Aggregation is:

(A) an abstraction through which relationships are treated as lower level entities

(B) an abstraction through which relationships are treated as higher level entities

(C) an abstraction through which relationships are not treated at all as entities

(D) none of the above

1. Suppose R is a relation schema and F is a set of functional dependencies on R. Further, suppose R1 and R2 form a decomposition of R. Then the decomposition is a lossless join decomposition of R provided that:

(A) R1∩R2→R1 is in F+

(B) R1∩R2→R2 is in F+

(C) both R1∩R2→R1 and R1∩R2→R2 functional dependencies are in F+

(D) at least one from R1∩R2→R1 and R1∩R2→R2 is in F+

1. In a heap, every element is …………… of all the elements in the subtree.

(A) maximum                (B) minimum

(C) sum                         (D) product

1. If (rear==maxsize-1) rear=0; else rear=rear+1; is required in:

(A) circular queue       (B) linear queue

(C) stack                        (D) deque

1. A high performance switching and multiplexing technology that utilizes fixed length packets to carry different types of traffic is:

(C) SONET       (D) None of the above

1. A conventional LAN bridge specifies only the functions of OSI:

(A) layers 1 and 2        (B) layers 1 through 3

(C) all layers                 (D) none of the above

1. An assembly program contains:

(A) imperative and declarative statements

(B) imperative and assembler directives

(C) imperative and declarative statements as well as assembler directives

(D) declarative statements and assembler directives

1. In which addressing mode, the effective address of the operand is generated by adding a constant value to the contents of register?

(A) absolute mode       (B) immediate mode

(C) indirect mode         (D) index mode

1. Which of the following are Assembler Directives?

(i) EQU  (ii) ORIGIN     (iii) START     (iv) END

(A) (ii), (iii) and (iv)

(B) (i), (iii) and (iv)

(C) (iii) and (iv)

(D) (i), (ii), (iii) and (iv)

1. Which of the following OS treats hardware as a file system?

(A) UNIX                        (B) DOS

(C) Windows NT          (D) None of the above

1. In which of the following, ready to execute processes must be present in RAM?

(A) multiprocessing     (B) multiprogramming

(C) multitasking           (D) all of the above

1. If the executing program size is greater than the existing RAM of a computer, it is still possible to execute the program if the OS supports:

(C) paging system       (D) none of the above

1. Software Quality Assurance(SQA) encompasses:

(A) verification

(B) validation

(C) both verification and validation

(D) none of the above

1. Which level is called as “defined” in capability maturity model?

(A) level 0          (B) level 3

(C) level 4         (D) level 1

1. COCOMO model is used for:

(A) product quality estimation

(B) product complexity estimation

(C) product cost estimation

(D) all of the above

1. Font sizes are usually expressed in points. One point is:

(A) 0.0069 inch                        (B) 0.0138 inch

(C) 0.0207 inch                        (D) 0.0276 inch

1. Assertion (A): Cellular telephone systems can handle a multitude of users.

Reasoning (R): Cellular telephone systems permit extensive frequency reuse in a small local area.

(A) Both (A) and (R) are true and (R) is the correct explanation for (A)

(B) Both (A) and (R) are true but (R) is not the correct explanation

(C) (A) is true but (R) is false

(D) (A) is false but (R) is true

1. E-commerce involves:

(A) Electronic Data Interchange

(B) Electronic mail

(C) Electronic Bulletin Boards

(D) All of the above

1. An example of a data mining algorithm which uses squared error score function is:

(A) CART algorithm

(B) back propagation algorithm

(C) a priority algorithm

(D) vector space algorithm

1. (I) Each object in the active directory of windows 2000 has an access control list.

(II) The scheme is a blueprint of all objects in the domain of windows 2000.

Which of the following is true?

(A) only (I)

(B) only (II)

(C) both (I) and (II)

(D) none of the above