Computer Science Study Materials for Competitive Exams

Sample Questions, Previous Year Solved Papers, Study Materials For Competitive Examinations Like UGC NET, SET And GATE Computer Science.

Monday, 31 October 2016

21.       What deletes the entire file except the file structure?
(A) ERASE       (B) DELETE
(C) ZAP             (D) PACK
Answer: C
22.       Which command classes text file, which has been created using “SET ALTERNATIVE” <FILE NAME> “Command” ?
Answer: A
23.       Data security threats include
(A) privacy invasion
(B) hardware failure
(C) fraudulent manipulation of data
(D) encryption and decryption
Answer: C
24.       Which of the following statements is true, when structure of database file with 20 records is modified?
(A) ? EOF ( ) Prints T
(B) ? BOF ( ) Prints F
(C) ? BOF ( ) Prints T
(D) ? EOF ( ) Prints F
Answer: A
25.       The SQL Expression
Select distinct T. branch name from branch T, branch S where T. assets > S. assets and S. branch-city = DELHI, finds the name of
(A) all branches that have greater asset than any branch located in DELHI.
(B) all branches that have greater assets than allocated in DELHI.
(C) the branch that has the greatest asset in DELHI.
(D) any branch that has greater asset than any branch located in DELHI.
Answer: A

26.       Dijkestra banking algorithm in an operating system, solves the problem of
(A) deadlock avoidance         (B) deadlock recovery
(C) mutual exclusion              (D) context switching
Answer: A
27.       The multiuser operating system, 20 requests are made to use a particular resource per hour, on an average the probability that no request are made in 45 minutes is
(A) e-15               (B) e-5
(C) 1 – e-5          (D) 1 – e-10
Answer: A
28.       On receiving an interrupt from an I/O device, the CPU
(A) halts for predetermined time.
(B) branches off to the interrupt service routine after completion of the current instruction
(C) branches off to the interrupt service routine immediately.
(D) hands over control of address bus and data bus to the interrupting device.
Answer: B
29.       The maximum amount of information that is available in one portion of the disk access arm for a removal disk pack (without further movement of the arm with multiple heads)
(A) a plate of data        (B) a cylinder of data
(C) a track of data        (D) a block of data
Answer: B
30.    Consider a logical address space of 8 pages of 1024 words mapped with memory of 32 frames. How many bits are there in the physical address?
(A) 9 bits                        (B) 11 bits
(C) 13 bits                     (D) 15 bits
Answer: D

Pages   2   3   4   5 

Sunday, 30 October 2016

41.       Enumeration is a process of
(A) Declaring a set of numbers
(B) Sorting a list of strings
(C) Assigning a legal values possible for a variable
(D) Sequencing a list of operators
Answer: C
42.       Which of the following mode declaration is used in C++ to open a file for input ?
(A) ios :: app                 (B) in :: ios
(C) ios :: file                  (D) ios :: in
Answer: D
43.       Data Encryption Techniques are particularly used for ……………….
(A) protecting data in Data Communication System.
(B) reduce Storage Space Requirement.
(C) enhances Data Integrity.
(D) decreases Data Integrity.
Answer: A
44.       Let L be a set accepted by a nondeterministic finite automaton. The number of states in non-deterministic finite automaton is |Q|. The maximum number of states in equivalent finite automaton that accepts L is
(A) |Q|                (B) 2|Q|
(C) 2|Q|–1           (D) 2|Q|
Answer: D
45.       What is the result of the following expression ?
(A) 1                   (B) 3
(C) 2                   (D) 0
Answer: D

46.       Back propagation is a learning technique that adjusts weights in the neural network by propagating weight changes.
(A) Forward from source to sink
(B) Backward from sink to source
(C) Forward from source to hidden nodes
(D) Backward from since to hidden nodes
Answer: B
47.       Match the following :
a. TTL                 1. High fan out
b. ECL               2. Low propagation delay
c. CMOS            3. High power dissipation
Code :
   a  b  c
(A) 3  2  1
(B) 1  2  3
(C) 1  3  2
(D) 3  1  2
Answer: A
48.       …………... is an “umbrella” activity that is applied throughout the software engineering process.
(A) Debugging             (B) Testing
(C) Designing              (D) Software quality assurance
Answer: D
49.       Identify the operation which is commutative but not associative ?
(A) OR               (B) NOR
(C) EX-OR        (D) NAND
Answer: B or D
50.    Given a Relation POSITION (Posting-No, Skill), then query to retrieve all distinct pairs of posting-nos. requiring skill is
(A) Select p.posting-No, p.posting-No
from position p
    where p.skill = p.skill
and p.posting-No < p.posting-No
(B) Select p1.posting-No, p2.posting-No
from position p1, position p2
where p1.skill = p2.skill
(C) Select p1.posting-No, p2.posting-No
from position p1, position p2
where p1.skill = p2.skill
and p1.posting-No < p2.posting-No
(D) Select p1.posting-No, p2.posting-No
from position p1, position p2
where p1.skill = p2.skill
and p1.posting-No = p2.posting-No
Answer: C

Pages   2   3   4   5 

Saturday, 29 October 2016

31.       Basis path testing falls under
(A) system testing                    (B) white box testing
(C) black box testing               (D) unit testing
Answer: B
32.       The User Work Area (UWA) is a set of Program variables declared in the host program to communicate the contents of individual records between
(A) DBMS & the Host record
(B) Host program and Host record
(C) Host program and DBMS
(D) Host program and Host language
Answer: C
33.       Consider the tree given below :
Using the property of eccentricity of a vertex, find every vertex that is the centre of the given tree.
(A) d&h                                      (B) c&k
(C) g, b, c, h, i, m                      (D) c&h
Answer: D
34.       The maximum number of keys stored in a B-tree of order m and depth d is
Answer: Marks given to all
maximum number of keys  = m(d+1)–1
35.       Which of the following is the most powerful parsing method ?
(A) LL(I)             (B) Canonical LR
(C) SLR             (D) LALR
Answer: B

36.       In UNIX, which of the following command is used to set the task priority ?
(A) init                (B) nice
(C) kill                (D) PS
Answer: B
37.       AES is a round cipher based on the Rijndal Algorithm that uses a 128-bit block of data. AES has three different configurations. …………. rounds with a key size of 128 bits, …………. rounds with a key size of 192 bits and ……………. rounds with a key size of 256 bits.
(A) 5, 7, 15                    (B) 10, 12, 14
(C) 5, 6, 7                      (D) 20, 12, 14
Answer: B
38.       Match the following IC families with their basic circuits :
a. TTL                 1. NAND
b. ECL               2. NOR
c. CMOS            3. Inverter
Code :
   a   b   c
(A) 1   2   3
(B) 3   2   1
(C) 2   3   1
(D) 2   1   3
Answer: A
39.       Match the following with respect to C++ data types :
a. User defined type    1. Qualifier
b. Built in type             2. Union
c. Derived type             3. Void
d. Long double                         4. Pointer
Code :
      a  b  c  d
(A) 2  3  4  1
(B) 3  1  4  2
(C) 4  1  2  3
(D) 3  4  1  2
Answer: A
40.    Given an empty stack, after performing push (1), push (2), Pop, push (3), push (4), Pop, Pop, push(5), Pop, what is the value of the top of the stack ?
(A) 4                   (B) 3
(C) 2                   (D) 1
Answer: D

Pages   2   3   4   5 

Friday, 28 October 2016

21.       Which API is used to draw a circle ?
(A) Circle()                    (B) Ellipse()
(C) Round Rect()         (D) Pie()
Answer: B
22.       In DML, RECONNCT command cannot be used with
(A) OPTIONAL Set                  (B) FIXED Set
(C) MANDATOR Set               (D) All of the above
Answer: B
23.       Coaxial cables are categorized by Radio Government rating are adapted for specialized functions. Category RG-59 with impedance 75 Ω used for
(A) Cable TV                 (B) Ethernet
(C) Thin Ethernet        (D) Thick Ethernet
Answer: A
24.       RAD stands for ………………
(A) Rapid and Design
(B) Rapid Aided Development
(C) Rapid Application Development
(D) Rapid Application Design
Answer: C
25.       Suppose that someone starts with a chain letter. Each person who receives the letter is asked to send it on to 4 other people. Some people do this, while some do not send any letter. How many people have seen the letter, including the first person, if no one receives more than one letter and if the chain letter ends after there have been 100 people who read it but did not send it out ? Also find how many people sent out the letter?
(A) 122 & 22                 (B) 111 & 11
(C) 133 & 33                 (D) 144 & 44
Answer: C
A full m-ary tree with L leaves has N =(ML-1)/(M-1) vertices and i= (L-1)/ (M-1)
internal vertices.
4-ary tree (M=4)
People who saw the letter = nodes
People who did not send the letter= leaves (L=100)
People who sent the letter: internal nodes (i)
n= (4.100-1)/ (4-1) =133 nodes
i= (100-1)/ (4-1) = 33

26.       A hash function f defined as f (key)=key mod 13, with linear probing is used to insert keys 55, 58, 68, 91, 27, 145. What will be the location of 79?
(A) 1       (B) 2
(C) 3       (D) 4
Answer: Marks given to all
f(55) = 3, f(58) = 6, f(68) =4, f(91) = 0, f(27) = 1, f(145) = 2, f(79) = 5
27.       Which of the following is true while converting CFG to LL(1) grammar ?
(A) Remove left recursion alone
(B) Factoring grammar alone
(C) Both of the above
(D) None of the above
Answer: C
28.       Identify the Risk factors which are associated with Electronic payment system.
(A) Fraudulent use of Credit Cards.
(B) Sending Credit Card details over internet.
(C) Remote storage of Credit Card details.
(D) All of the above
Answer: D
29.       Which of the following are two special functions that are meant for handling exception, that occur during exception handling itself ?
(A) Void terminate() and Void unexpected()
(B) Non void terminate() and void unexpected()
(C) Void terminate() and non void unexpected()
(D) Non void terminate() and non void unexpected()
Answer: A
30.    Which of the following memory allocation scheme suffers from external fragmentation ?
(A) Segmentation        (B) Pure demand paging
(C) Swapping               (D) Paging
Answer: A

Pages   2   3   4   5 

Thursday, 27 October 2016

1.       How many OSI layers are covered in the X.25 standard?
(A) Two              (B) Three
(C) Seven         (D) Six
Answer: B
2.       Layer one of the OSI model is .................
(A) physical layer         (B) link layer
(C) transport layer        (D) internet work layer
Answer: A
3.       The X.25 standard specifies a ...............
(A) technique for start-stop data
(B) technique for dial access
(C) DTE/DCE interface
(D) None of above
Answer: C
4.       Which of the following communication modes support two-way traffic but in only one direction at a time?
(A) simplex                                (B) half duplex
(C) three-quarters duplex       (D) all of the above
Answer: B
5.       Which of the following might be used by a company to satisfy its growing communications needs?
(A) front end processor           (B) multiplexer
(C) controller                            (D) All of the above
Answer: D

6.       What is the number of separate protocol layers at the serial interface gateway specified by the X.25 standard?
(A) 4       (B) 2
(C) 6       (D) 3
Answer: D
7.       The interactive transmission of data within a time sharing system may be best suited to
(A) simplex lines          (B) half-duplex lines
(C) full duplex lines    (D) None of these
Answer: B
8.       Which of the following is considered a broad band communication channel?
(A) coaxial cable                      (B) fiber optics cable
(C) microwave circuits                        (D) all of the above
Answer: D
9.       Which of the following is not a transmission medium?
(A) telephone lines     (B) coaxial cables
(C) modem                    (D) microwave systems
Answer: C
10.    Which of the following does not allow multiple uses or devices to share one communication line?
(A) doubleplexer          (B) multiplexer
(C) concentrator           (D) controller
Answer: A