Computer Science -2007 SetA

1. The Boolean expression Y B bar A bar C bar is given by


A C bar

B C bar

C bar

AB


2. The circuit shown in the following Figure realizes the function


<img src='./qimages/1638-2.jpg'>

<img src='./qimages/1638-2-a.jpg'>


3. The circuit shown in the given Figure is a

<img src='./qimages/1638-3.jpg'>


full adder

full subtracter

shift register

decade counter Page


4. When two numbers are added in excess-3 code and the sum is less than then in order to get the correct answer it is necessary to


subtract 0011 from the sum

add 0011 to the sum

subtract 0110 from the sum

add 0110 to the sum


5. The characteristic equation of an SR flip-flop is given by

<img src='./qimages/1638-5.jpg'>


6. A graph with "n" vertices and n-1 edges that is not a tree, is


Connected

Disconnected

Euler

A circuit


7. If a graph requires k different colours for its proper colouring, then the chromatic number of the graph is


1

k

k-1

k/2


8. A read bit can be read

and written by CPU

and written by peripheral

by pheripheral and written by CPU

by CPU and written by the peripheral


9. Eigen vectors of <img src='./qimages/1638-9.jpg'> are


<img src='./qimages/1638-9a.jpg'>

<img src='./qimages/1638-9b.jpg'>

<img src='./qimages/1638-9c.jpg'>

<img src='./qimages/1638-9d.jpg'>



10. The term "aging" refers to


booting up the priority of a process in multi-level of queue without feedback.

gradually increasing the priority of jobs that wait in the system for a long time to remedy infinite blocking.

keeping track of the following a page has been in memory for the purpose of LRU replacement

letting job reside in memory for a certain amount of time so that the number of pages required can be estimated accurately.


11. Consider a set of n tasks with known runtimes r1,r2...rn to be run on a uniprocessor machine. Which of the following processor scheduling algorithms will result in the maximum throughput?


Round Robin

Shortest job first

Highest response ratio next

first cum first served


12. Consider a job scheduling problem with four jobs J1 J2 J3 and J4 with corresponding deadlines: Which of the following is not a feasible schedule without violating any job deadline?


J2, J4, J1, J3

J4, J1, J2, J3

J4, J2, J1, J3

J4, J2, J3, J1


13. By using an eight bit optical encoder the degree of resolution that can be obtained is (approximately)

1.8 deg

3.4 deg

2.8 deg

1.4 deg


14. The principal of locality of reference justifies the use of


virtual memory

interrupts

main memory

cache memory


15. Consider the following psuedocode <img src='./qimages/1638-15.jpg'> What is the value of i at the end of the pseudocode?


4

5

6

7

16. The five items: and E are pushed in a stack, one after the other starting from A. The stack is popped four times and each element is inserted in a queue. Then two elements are deleted from the queue and pushed back on the stack. Now one item is popped from the stack. The popped item is


A

B

C

D


17. Round Robin scheduling is essentially the pre-emptive version of


FIFO

Shortest Job First

Shortest remaining time

Longest remaining time


18. The number of digit 1 present in the binary representation of 3 x 512 x 64 x 8 +3is

8

9

10

12


19. Assume that each character code consists of 8 bits. The number of characters that can be transmitted per second through an synchronous serial line at 2400 baud rate, and with two stop bits is


109

216

218

219


20. If the bandwidth of a signal is 5kHz and the lowest frequency is 52kHz, what is the highest frequency

5kHz

10kHz

47kHz

57kHz


21. An Ethernet hub


functions as a repeater

connects to a digital PBX

connects to a token-ring network

functions as a gateway


22. Phase transition for each bit are used in


Amplitude modulation

Carrier modulation

Manchester encoding

NRZ encoding


23. Study the following programme <img src='./qimages/1638-23.jpg'> Which of the following is printed as a result of the call demo


1441

3443

12344321

43211234


24. Bit stuffing refers to

inserting a in user stream to differentiate it with a flag

inserting a in flag stream to avoid ambiguity

appending a nibble to the flag sequence

appending a nibble to the use data stream


25. What is the name of the technique in which the operating system of a computer executes several programs concurrently by switching back and forth between them?


Partitioning

Multi tasking

Windowing

Paging


26. If there are five routers and six networks in an Intranet using link state routing, how many routing tables are there?

1

5

6

11


27. Virtual memory is

Part of Main Memory only used for swapping

A technique to allow a program, of size more than the size of the main memory, to run

Part of secondary storage used in program execution

None of these


28. The level of aggregation of information required for operational control is

Detailed

Aggregate

Qualitative

None of the above


29. The set of all Equivalence classes of a set A of Cardinality C


is of cardinality 2c

has the same cardinality as A.

forms a partition of A

is of cardinality C2


30. 0.75 in decimal system is equivalent to in octal system


0.60

0.52

0.54

0.50


31. In an SR latch made by cross coupling two NAND gates, if both S and R inputs are set to then it will result in








Indeterminate states

32. Identify the correct translation into logical notation of the following assertion. Some boys in the class are taller than all the girls Note: taller(x,y) is true if x is taller than y.

<img src='./qimages/1638-32.jpg'>


33. Company X shipped 5 computer chips, 1 of which was defective, and Company Y shipped 4 computer chips, 2 of which were defective. One computer chip is to be chosen uniformly at random from the 9 chips shipped by the companies. If the chosen chip is found to be defective, what is the probability that the chip came from Company


2/9

4/9

2/3

1/2


34. Ring counter is analogous to


Toggle Switch

Latch

Stepping Switch

S-R flip flop


35. The output 0 and 1 level for TTL Logic family is approximately


0.1 and 5V

0.6 and 3.5V

0.9 and 1.75V

-1.75 and 0.9V


36. Consider a computer system that stores floating-point numbers with 16-bit mantissa and an 8-bit exponent, each in two's complement. The smallest and largest positive values which can be stored are

<img src='./qimages/1638-36.jpg'>


37. In comparison with static RAM memory, the dynamic RAM memory has


lower bit density and higher power consumption

higher bit density and higher power consumption

lower bit density and lower power consumption

higher bit density and lower power consumption.


38. The Hexadecimal equivalent of 01111100110111100011 is


CD73E

ABD3F

7CDE3

FA4CD


39. Disk requests are received by a disk drive for cylinder 25, 18, 39, 8 and 35 in that order. A seek takes 5msec per cylinder moved. How much seek time is needed to serve these requests for a Shortest Seek First algorithm? Assume that the arm is at cylinder?,0 when the last of these requests is made with none of the requests yet served


125 msec

295 msec

575 msec

750 msec


40. Consider a system having resources of the same type. The resources are shared by 3 processes which have peak time demands of respectively. The minimum value of that ensures that deadlock will never occur is


11

12

13

14


41. A task in a blocked state

is executable

is running

must still be placed in the run queues

Is waiting for some temporarily unavailable resources.


42. Semaphores

synchronize critical resources to prevent deadlock

synchronize critical resources to prevent contention

are used to do I/O

are used for memory management.


43. On a system using non-preemptive scheduling, processes with expected
run times of 18, 9 and 12 are in the ready queue. In what order should
they be run to minimize wait time?


5,12,9,18

5,9,12,18

12,18,9,5

9,12,18,5


44. The number of page frames that must be allocated to a running process in a virtual memory environment is determined by


the instruction set architecture

page size

number of processes in memory

physical memory size

45. A program consists of two modules executed sequentially. let and respectively denote the probability density functions of time taken to execute the two modules. The probability density function of the overall time taken to execute the program is given by

<img src='./qimages/1638-46.jpg'>


46. Consider a small 2-way set-associative cache memory, consisting of four blocks.
For choosing the block to be replaced, use the least recently scheme. The number of cache misses for the following sequence of block addresses is


2

3

4

5

47. Which commands are used to control access over objects in relational database?


CASCADE MVD

GRANT REVOKE

QUE QUIST

None of these


48. Which of the following is aggregate function in SQL?


Avg

Select

Ordered by

distinct


49. One approach to handling fuzzy logic data might be to design a computer using ternary logic so that data could be stored as "true," "false," and "unknown." If each ternary logic element is called a flit, how many flits are required to represent at least 256 different values?

4

5

6

7

50. A view of a database that appears to an application program is known as

Schema

Subschema

Virtual table

None of these

51. Armstrong's inference rule doesn't determine

Reflexivity

Augmentation

Transitivity

Mutual dependency

52. Which operation is used to extract specified columns from a table?

Project

Join

Extract

Substitute


53. In the Big-Endian system, the computer stores


MSB of data in the lowest memory address of data unit

LSB of data in the lowest memory address of data unit

MSB of data in the highest memory address of data unit

LSB of data in the highest memory address of data unit


54. BCNF is not used for cases where a relation has

Two (or more) candidate keys

Two candidate keys and composite

The candidate key overlap

Two mutually exclusive foreign keys


55. Selection sort algorithm design technique is an example of

Greedy method

Divide-and-conquer

Dynamic Programming

Backtracking


56. Which of the following RAID level provides the highest Data Transfer Rate (ReadIWrite)


RAID 1

RAID 3

RAID 4

RAID 5

57. Which of the following programming language(s) provides garbage collection automatically


Lisp



Fortran

C

58. The Average case and worst case complexities for Merge sort algorithm are



O(n log2

O(n log

O(n log O(n log 2n

59. The time taken by binary search algorithm to search a key in a sorted array of n elements is

O (lOg2n)

O

O log2n)

O


60. Which of the following is correct with respect to Two phase commit protocol?


Ensures serializability

Prevents Deadlock

Detects Deadlock

Recover from Deadlock


61. The Fibonacci sequence is the sequence of integers











62. Let X be the adjacency matrix of a graph G with no self loops. The entries along the principal diagonal of X are

all zeros

all ones

both zeros and ones

different


63. Which of these is not a feature of WAP 2.0


Push Pull Model

Interface to a storage device

Multimedia messaging

Hashing


64. Feedback queues


are very simple to implement

dispatch tasks according to execution characteristics

are used to favour real time tasks

require manual intervention to implement properly


65. Which of the following is not a UML DIAGRAM?


Use Case

Class Diagram

Analysis Diagram

Swimlane Diagram


66. Silly Window Syndrome is related to

Error during transmission

File transfer protocol

Degrade in TCP performance

Interface problem


67. To execute all loops at their boundaries and within their operational bounds is an example of

Black Box Testing

Alpha Testing

Recovery Testing

white Box Testing


68. SSL is not responsible for

Mutual authentication of client seNer

Secret communication

Data Integrity protection

Error detection correction


69. A rule in a limited entry decision table is a

row of the table consisting of condition entries

row of the table consisting of action entries

column of the table consisting of condition entries and the corresponding action entries

columns of the table consisting of conditions of the stub


70. The standard for certificates used on internet is

X.25

X.301

X.409

X.509

71. Hashed message is signed by a sender using

his public key

his private key

receiver's public key

receiver's private key


72. An email contains a textual birthday greeting, a picture of a cake, and a song. The order is not important. What is the content-type?


Multipart/mixed

Multipart/parallel

Multipart/digest

Multipart/alternative


73. Range of IP Address from 224.0.0.0 to 239.255.255.255 are


Reserved for loopback

Reserved for broadcast

Used for multicast packets

Reserved for future addressing


74. IEEE 802.11 is standard for


Ethernet

Bluetooth

Broadband Wireless

Wireless LANs

75. When a host on network A sends a message to a host on network which address does the router look at?

Port

IP

Physical

Subnet mask

76. Which of the following is not an approach to Software Process Assessment?

SPICE(ISO/IEC15504)

Standard CMMI Assessment Method for process improvement

ISO 9001:2000

IEEE 2000:2001


77. A physical DFD specifies

what processes will be used

who generates data and who processes it

what each person in an organization does

which data will be generated


78. In UML diagram of a class

state of object cannot be represented

state is irrelevant

state is represented as an attribute

state is represented as a result of an operation


79. which of the following models is used for software reliability?

Waterfall

Musa

COCOMO

Rayleigh


80. Djikstra's algorithm is used to

Create LSAs

Flood an internet with information

Calculate the routing tables

Create a link state database