UGC NET CS 2011 Dec-Paper-2

Question 1
Which of the following data structure is Non-linear type ?
A
Strings
B
Lists
C
Stacks
D
None of the above
       Data-Structures       Lnear-Data-Structure
Question 1 Explanation: 
A data structure is said to be linear if its elements form a sequence or a linear list.
Examples:
1. Array
2. Linked List
3. Stacks
4. Queues
Question 2
The total number of comparisons in a bubble sort is
A
0(log n)
B
0(n log n)
C
0(n)
D
None of the above
       Algorithms       Sorting
Question 2 Explanation: 
The total number of comparisons in a bubble sort is O(n2)
Question 3
Which of the following is a bad example of recursion ?
A
Factorial
B
Fibonacci numbers
C
Tower of Hanoi
D
Tree traversal
       Data-Structures       Recursion
Question 3 Explanation: 
→ Fibonacci Series using recursion using condition is
Condition: fibonacci(n-1) + fibonacci(n-2)
Recurrence relation is: T(n)=2T(n-1)+C
Time Complexity: O(2n)
→ Factorial number using recursion is
Condition: fact(n-1)*n
Recurrence relation is: T(n)=T(n+1)+1
Time Complexity: O(n)
→ Tower of Hanoi using recursion is
Step-1: Hanoi(disk - 1, source, aux, dest)
Step-2: move disk from source to dest
Step-3: Hanoi(disk - 1, aux, dest, source)
Recurrence relation is: T(n)=2T(n-1)+C
Time Complexity: O(2n)
→ Tree traversals like Preorder,Postorder and Inorder using recursion only
Note: Recursion is best in the case of Tower of Hanoi,Factorial number and Tree traversals but it is not give good performance to fibonacci numbers.
Question 4
Domain and Range of the function Y = -√(-2x + 3) is
A
x ≥3/2, y ≥ 0
B
x >3/2, y ≤ 0
C
x ≥3/2, y ≤ 0
D
x ≤3/2, y ≤ 0
       Engineering-Mathematics       Calculus
Question 5
Maximum number of edges in a n-Node undirected graph without self loop is
A
n2
B
n(n-1)
C
n(n+1)
D
n(n-1)/2
       Engineering-Mathematics       Graph-Theory
Question 5 Explanation: 
The set of vertices has size n, the number of such subsets is given by the binomial coefficient C(n,2)⋅C(n,2) = n(n-1)/2
Question 6
A hash table has space for 75 records, then the probability of collision before the table is 6% full.
A
25
B
20
C
35
D
30
E
None of the above
       Engineering-Mathematics       Probability
Question 6 Explanation: 
Given data,
-- Hash table has space =75 slots.
-- For 6% filling it must take =6 slots.
-- Probability of no collision for first 6 entries=?
Step-1: According to given data,
= (75P6) / (756)
= 0.814586387
Step-2: We have to find at least one collision occurs in 6 entries
=1-Probability of no collision for first 6 entries
= 1-0.814586387
= 0.185413613
Note: Given options are wrong. Given option-B is correct answer according to original key.
Question 7
BCC in the internet refers to
A
Black carbon copy
B
Blind carbon copy
C
Blank carbon copy
D
Beautiful carbon copy
       Computer-Basics       E-mail
Question 7 Explanation: 
→ Blind carbon copy(BCC) is a useful way to let others see an email you sent without the main recipient knowing. It is faster than sending the original message and then forwarding the sent message to the other recipients. It is also good netiquette to use Bcc when copying a message to many people.
Question 8
Hub is a term used with
A
A Star Networks
B
A Ring Networks
C
A Router
D
A Bridge
       Computer-Networks       Hardware-and-various-devices-in-networking
Question 8 Explanation: 
→ Hub is a term used with a star networks. When compare to switch, it is not an intelligent device.
Question 9
The amount of uncertainty in a system of symbol is called
A
Bandwidth
B
Entropy
C
Loss
D
Quantum
       Data-Communication       Information-theory
Question 9 Explanation: 
→ The amount of uncertainty in a system of symbol is called entropy. → Generally we can call entropy is disorder or uncertainty.
Question 10
Which of the following network access standard disassembler is used for connection station to a packet switched network ?
A
X.3
B
X.21
C
X.25
D
X.75
       Computer-Networks       Switching
Question 10 Explanation: 
An X.25 WAN consists of packet-switching exchange (PSE) nodes as the networking hardware, and leased lines, plain old telephone service connections, or ISDN connections as physical links.
Question 11
A station in a network in a network forward incoming packets by placing them on its shortest output queue. What routing algorithm is being used ?
A
Hot potato routing
B
Flooding
C
Static routing
D
Delta routing
       Computer-Networks       Routing
Question 11 Explanation: 
→ Hot-potato routing is the practice of passing traffic off to another autonomous system as quickly as possible, thus using their network for wide-area transit. → Cold-potato routing is the opposite, where the originating autonomous system holds onto the packet until it is as near to the destination as possible.
Question 12
Start and stop bits are used in serial communications for
A
Error detection
B
Error correction
C
Synchronization
D
Slowing down the communication
       Computer-Organization       Synchronous-and-asynchronous-Communication
Question 12 Explanation: 
Start and stop bits are used in serial communications for Synchronization.
Question 13
For a data entry project for office staff who have never used computers before (user interface and user friendliness are extremely important), one will use
A
Spiral model
B
Component based model
C
Prototyping
D
Waterfall model
       Software-Engineering       Types-of-Models
Question 14
An SRS
A
establishes the basis for agreement between client and the supplier.
B
provides a reference for validation of the final product.
C
is a prerequisite to high quality software.
D
all of the above.
       Software-Engineering       Software-requirement-specification
Question 14 Explanation: 
→ Software Requirement Specification(SRS) establishes the basis for agreement between client and the supplier. It provides a reference for validation of the final product. SRS is a prerequisite to high quality software.
→ The system is considered as a black box whose internal details are not known that is, only its visible external (input/output) behavior is documented.
→ The Software Requirement Specification(SRS) is said to be Consistent if and only if no subset of individual requirements described in it conflict with each other.
Question 15
McCabe’s cyclomatic metric V(G) of a graph G with n vertices, e edges and p connected component ise
A
e
B
n
C
e – n + p
D
e – n + 2p
       Software-Engineering       Cyclomatic-metric
Question 15 Explanation: 
Cyclomatic complexity uses 3 formulas
1. Number of regions + 1
2. Predicate + 1
3.Edges-Vertices+2(Connected components)
As per the above question, c=cyclomatic complexity
e=number of edges
n=number of vertices
p=predicates
Question 16
Emergency fixes known as patches are result of
A
adaptive maintenance
B
perfective maintenance
C
corrective maintenance
D
none of the above
       Software-Engineering       Software-configuration-management
Question 16 Explanation: 
Software maintenance is the modification of a software product after delivery to correct faults, to improve performance or other attributes.
Software maintenance types: 1. Adaptive: modifying the system to cope with changes in the software environment (DBMS, OS)
2. Perfective: Implementing new or changed user requirements which concern functional enhancements to the software.
3. Corrective: Diagnosing and fixing errors, possibly ones found by users.
4. Preventive: Increasing software maintainability or reliability to prevent problems in the future.
Question 17
Design recovery from source code is done during
A
reverse engineering
B
re-engineering
C
reuse
D
all of the above
       Software-Engineering       Software-design
Question 17 Explanation: 
Design recovery from source code is done during reverse engineering, re-engineering and reusability.
Question 18
Following is used to demonstrate that the new release of software still performs the old one did by rerunning the old tests :
A
Functional testing
B
Path testing
C
Stress testing
D
Regression testing
       Software-Engineering       Software-testing
Question 18 Explanation: 
→ Regression testing is re-running functional and non-functional tests to ensure that previously developed and tested software still performs after a change. If not, that would be called a regression.
→ Changes that may require regression testing include bug fixes, software enhancements, configuration changes, and even substitution of electronic components.
→ As regression test suites tend to grow with each found defect, test automation is frequently involved.
Question 19
The post order traversal of a binary tree is DEBFCA. Find out the preorder traversal.
A
ABFCDE
B
ADBFEC
C
ABDECF
D
ABDCEF
       Data-Structures       Binary-Trees
Question 19 Explanation: 
Post order traversal tree is look like

Postorder: DEBFCA
Inorder: DBEAFC
Preorder: ABDECF
Question 20
B+ tree are preferred to binary tree in database because
A
Disk capacities are greater than memory capacities
B
Disk access much slower than memory access
C
Disk data transfer rates are much less than memory data transfer rate
D
Disk are more reliable than memory
       Database-Management-System       B-and-B+-Trees
Question 20 Explanation: 
In B+ trees it is easy to reduce the number of last level access from the disk when the disk size is too large.
Question 21
What deletes the entire file except the file structure ?
A
ERASE
B
DELETE
C
ZAP
D
PACK
       Database-Management-System       Commands
Question 21 Explanation: 
→ PACK statement removes all records marked for deletion permanently.
→ DELETE statement is used to delete existing records in a table.
→ ZAP deletes the entire file except the file structure.
Question 22
Which command classes text file, which has been created using“SET ALTERNATIVE” <FILE NAME>“Command” ?
A
SET ALTERNATE OFF
B
CLOSE DATABASE
C
CLOSE ALTERNATE
D
CLEAR ALL
       Database-Management-System       SQL
Question 22 Explanation: 
SET ALTERNATE: Controls the recording of input and output in an alternate text file.
Syntax:
SET ALTERNATE on | OFF
SET ALTERNATE TO [ | ? | [ADDITIVE]]
→ The default for SET ALTERNATE is OFF. To change the default, set the ALTERNATE parameter in the [OnOffSetting Settings] section of PLUS.ini. To set a default file name for use with SET ALTERNATE, specify an ALTERNATE parameter in the [Command Settings] section of PLUS.ini.
→ Issuing SET ALTERNATE OFF does not close the alternate file. Before accessing the contents of an alternate file, formally close it with CLOSE ALTERNATE or SET ALTERNATE TO (with no file name). This ensures that all data recorded by dBASE Plus for storage in the alternate file is transferred to disk, and automatically turns SET ALTERNATE to OFF.
Question 23
Data security threats include
A
privacy invasion
B
hardware failure
C
fraudulent manipulation of data
D
encryption and decryption
       Computer-Networks       Security
Question 23 Explanation: 
→ Hardware failure, encryption and decryption is not related to data security threats.
→ Privacy invasion and fraudulent manipulation of data is related to data security threats. But fraudulent manipulation of data is most appropriate answer.
Question 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
       Database-Management-System       File-System
Question 24 Explanation: 
Here, EOF means End of File. When structure of database file with 20 records is modified then ?EOF will prints value is T. Here, T means TRUE.
Question 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.
       Database-Management-System       SQL
Question 25 Explanation: 

Since the query is co-related that is same table is being used two times for comparison so compare each entry of table T with every entry of table S. Then the outcome for above query will be

So the output contains all branches that have greater asset than any branch located in DELHI.
Question 26
Dijkstra's banking algorithm in an operating system, solves the problem of
A
deadlock avoidance
B
deadlock recovery
C
mutual exclusion
D
context switching
       Operating-Systems       Deadlock
Question 26 Explanation: 
Dijkstra's banking algorithm in an operating system, solves the problem of deadlock avoidance.
Question 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
       Engineering-Mathematics       Probability
Question 27 Explanation: 
Probability of events for a Poisson distribution:
An event can occur 0, 1, 2, … times in an interval. The average number of events in an interval is designated (lambda). is the event rate, also called the rate parameter. The probability of observing k events in an interval is given by the equation
P(k events in interval)=e [(λk)/k!]
Where
→ λ is the average number of events per interval
→ e is the number 2.71828... (Euler's number) the base of the natural logarithms
→ k takes values 0, 1, 2, …
→ k! = k × (k − 1) × (k − 2) × … × 2 × 1 is the factorial of k.
→ Now it is given that in 1 hour (60 minutes) 20 requests are made
→ In 1 minute number of requests made= 20/60
→ In 45 minutes total number of requests made = (20/60) * 45
= 15
Probability= (e-15 *(15)0) / 0!
= e-15
Question 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.
       Computer-Organization       Interruption
Question 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
       Computer-Organization       Secondary-Memory
Question 29 Explanation: 
A cylinder of data having 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).
Question 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
       Operating-Systems       Memory-Management
Question 30 Explanation: 
Since we know page and frame both have the same size and since page size is given as 1024 words, it means frame size is of 1024 i.e. 210. Hence to uniquely identify each word inside a frame 10-bits are needed.
→ Number of frames is given as 32 i.e 25. So each frame can be uniquely identified using 5-bits.
→ Hence the total number of bits needed to identify a word inside memory is 5+10 = 15 bits.

Question 31
CPU does not perform the operation
A
data transfer
B
logic operation
C
arithmetic operation
D
all of the above
       Computer-Organization       Hardware Devices
Question 31 Explanation: 
A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions.
Question 32
A chip having 150 gates will be classified as
A
SSI
B
MSI
C
LSI
D
VLSI
       Digital-Logic-Design       Logic-Gates
Question 32 Explanation: 

Question 33
If an integer needs two bytes of storage, then the maximum value of unsigned integer is
A
216 – 1
B
215 – 1
C
216
D
215
       Digital-Logic-Design       Number-Systems
Question 33 Explanation: 
= If an integer needs two bytes of storage, then the maximum value of a signed integer is 2n-1 -1
= 215 -1
Question 34
Negative numbers cannot be represented in
A
signed magnitude form
B
1’s complement form
C
2’s complement form
D
none of the above
       Digital-Logic-Design       Number-Systems
Question 34 Explanation: 
Negative numbers can be represented in
1. Signed magnitude form
2. 1’s complement form
3. 2’s complement form
Question 35
The cellular frequency reuse factor for the cluster size N is
A
N
B
N2
C
1/N
D
1/N2
       Data-Communication       Cellular-Networks
Question 35 Explanation: 
The frequency reuse factor is related to cluster size then the frequency reuse factor=1/N
Question 36
X – = Y + 1 means
A
X = X – Y + 1
B
X = –X – Y – 1
C
X = –X + Y + 1
D
= X – Y – 1
       Programming       Operator
Question 36 Explanation: 
In Programming languages like C,C++ and Java we can write X-=Y+1 into X=X-Y+1
Note: X*=Z+1 → X=X*Z+1
X/=Z+1 → X=X/Z+1
X+=Z+1 → X=X+Z+1
Question 37
Handoff is the mechanism that
A
transfer an ongoing call from one base station to another
B
initiating a new call
C
dropping an ongoing call
D
none of above
       Data-Communication       Cellular-Networks
Question 37 Explanation: 
Handoff is the mechanism that transfer an ongoing call from one base station to another.
Hard handover (or) Hard Handoff: Early systems used hard handoff. In a hard handoff, a mobile station only communicates with one base station. When the MS moves from one cell to another, communication must first be broken with the previous base station before communication can be established with the new one.
Soft handover (or) Soft Handoff: New systems use a soft Handoff. In this case, a mobile station can communicate with base stations at the same time. This means that, during handoff, a mobile station may continue with the new base station before breaking off from the old one.
Question 38
Which one of the following statement is false ?
A
Context-free languages are closed under union.
B
Context-free languages are closed under concatenation.
C
Context-free languages are closed under intersection.
D
Context-free languages are closed under Kleene closure
       Theory-of-Computation       Context-Free-Language
Question 38 Explanation: 
Context-free languages are closed under Union,Concatenation and Kleene closure.
Context-free languages are not closed under set difference,Complementation and intersection.
Question 39
All of the following are examples of real security and privacy risks except
A
Hackers
B
Spam
C
Viruses
D
Identify theft
       Computer-Networks       Security
Question 39 Explanation: 
→ Hackers,Viruses and identity theft are real security and privacy risks.
→ Spam is not related to real security and privacy risk.
Note: Spam is nothing but unwanted message(or) mail.
Question 40
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 streamlined protocol with minimal error and flow control capabilities
D
ATM is also known as cell delays.
       Computer-Networks       Application-Layer-Protocol
Question 40 Explanation: 
FALSE: The ATM adaptation layer is service dependent.
TRUE: Logical connections in ATM are referred to as virtual channel connections.
TRUE: ATM is streamlined protocol with minimal error and flow control capabilities
TRUE: ATM is also known as cell delays.
Question 41
Software risk estimation involves following two tasks :
A
Risk magnitude and risk impact
B
Risk probability and risk impact
C
Risk maintenance and risk impact
D
Risk development and risk impact
       Software-Engineering       Software-testing
Question 41 Explanation: 
Software Risk estimation involves risk probability and risk impact.
Risk impact factors are
1. Negligible [low]
2. Marginal
3. Critical
4. Catastrophic [High]
Risk exposure:
RE=P*C
P=The probability of occurrence for a risk
C=The cost to the project should the risk actually occur
Question 42
The number of bits required for an IPv6 address is
A
16
B
32
C
64
D
128
       Computer-Networks       IPv6
Question 42 Explanation: 
→ The number of bits required for an IPv6 address is 128.
→ The number of bits required for an IPv4 address is 32
Question 43
The proposition ~qvp is equivalent to
A
p → q
B
q → p
C
p ↔ q
D
p ∨ q
       Engineering-Mathematics       Propositional-Logic
Question 43 Explanation: 

Hence Option-B is correct answer
Question 44
Enterprise Resource Planning (ERP)
A
has existed for over a decade.
B
does not integrate well with the functional areas other than operations.
C
is inexpensive to implement.
D
automate and integrates the majority of business processes
       Computer-Networks       E-commerce
Question 44 Explanation: 
Enterprise Resource Planning (ERP) is automate and integrates the majority of business processes. ERP is the integrated management of core business processes, often in real-time and mediated by software and technology.
Question 45
Which of the following is false concerning Enterprise Resource Planning (ERP) ?
A
It attempts to automate and integrate the majority of business processes.
B
It shares common data and practices across the enterprise.
C
It is inexpensive to implement.
D
It provides and access information in a real-time environment.
       Computer-Networks       E-commerce
Question 45 Explanation: 
TRUE: It attempts to automate and integrate the majority of business processes.
TRUE: It shares common data and practices across the enterprise.
FALSE: It is expensive to implement.
TRUE: It provides and access information in a real-time environment.
Question 46
To compare, overlay or cross analyze to maps in GIS
A
both maps must be in digital form
B
both maps must be at the same equivalent scale.
C
both maps must be on the same coordinate system
D
All of the above
       Database-Management-System       data-mining
Question 46 Explanation: 
All are correct.
Question 47
Web Mining is not used in which of the following areas ?
A
Information filtering
B
Crime fighting on the internet
C
Online transaction processing
D
Click stream analysis.
       Database-Management-System       data-mining
Question 47 Explanation: 
Web Mining is used to filtering information,online transaction processing and click stream analysis.
Question 48
A telephone conference call is an example of which type of communications ?
A
same time / same place
B
same time / different place
C
different time / different place
D
different time / same place
       Data-Communication       Cellular-Networks
Question 48 Explanation: 
A telephone conference call is an example of same time / different place type of communications.
Question 49
What is the probability of choosing correctly an unknown integer between 0 and 9 with 3 chances ?
A
963/1000
B
973/1000
C
983/1000
D
953/1000
E
None of the above
       Engineering-Mathematics       Probability
Question 49 Explanation: 
Probability of getting a number = 1/10
Probability of not getting a number = 1- 1/(10) = 9/10
Now probability that correct number is chosen in first chance= 1/10
probability that correct number is chosen in second chance= (9/10)* (1/10)
probability that correct number is chosen in first chance= (9/10)* (9/10) *(1/10)
So total probability = (1/10)+ [(9/10)* (1/10) ]+ [(9/10)* (9/10) *(1/10)]
= (1/10)+(9/100)+(81/1000)
= 271/1000
Note: Excluded for evaluation because given options are wrong
Question 50
The number of nodes in a complete binary tree of height h (with roots at level 0) is equal to
A
20 + 21 + ….. 2h
B
20 + 21 + ….. 2h – 1
C
20 + 21 + ….. 2h + 1
D
21 + ….. 2h + 1
       Data-Structures       Binary-Trees
Question 50 Explanation: 
The number of nodes in a complete binary tree of height h (with roots at level 0) is equal to 20 + 21 + ….. 2h. because every phase we are getting 2h.
Suppose, in level-3, it have 23=8 nodes.
There are 50 questions to complete.