UGC NET CS 2005 june-paper-2

Question 1
Which of the following is not true ?
A
Power of deterministic automata is equivalent to power of non-deterministic automata.
B
Power of deterministic pushdown automata is equivalent to power of non-deterministic pushdown automata.
C
Power of deterministic turing machine is equivalent to power of non-deterministic turing machine.
D
All the above
       Theory-of-Computation       Finite-Automata
Question 1 Explanation: 
→ NPDA(Non deterministic Pushdown Automata) and DPDA(Deterministic Pushdown Automata) are not equivalent in power.
→ NPDA is more powerful than DPDA which means for every language for which a dpda exist, there exist an NPDA but there are some languages that are accepted by NPDA but are not accepted by DPDA.
→ In case of DFA and NFA they are equivalent in power. So for every language accepted by DFA there exists an NFA and vice versa.
Hence,we can’t convert NPDA to DPDA always and we can convert NFA to an equivalent DFA always.
→ In case of DTM and NTM they are equivalent in power.
Question 2
Identify the language which is not context-free.
A
L = { wwR ǀ wε{0,1}* }
B
L = { a​ n​ b​ n​ ǀ n≥0 }
C
L = { ww ǀ wε{0,1}* }
D
L = { a​ n​ b​ m​ c​ m​ d​ n​ ǀ n,m ≥0 }
       Theory-of-Computation       Context-Free-Language
Question 2 Explanation: 
Option-A​ is a CFL because for this we can have a non deterministic pushdown automata which will accept the string by exploring all the possibilities on each input character.
Option-B​ is correct because we can have a deterministic pushdown automata which will push all the "a" as they come as input and when "b" comes as input for every "b" one "a" will be popped. So in this way we can design a pushdown automata which will accept a​ n​ b​ n​ . Hence a​ n​ b​ n​ is a CFL.
Option-C​ is not a CFL because we can't design a pushdown which can accept CFL. Suppose a string "abcabc". Now let's say pushdown automata recognize w=abc after symbol "c" now when "a" come as input after "c" the pushdown automata have to pop "a" i.e. initial input symbol "a" but top of the stack contains "c" as top element. So in this way we can't have any pushdown automata which can accept "ww" language. So it is not a CFL.
Option-D​ is a CFL because we can design a pushdown automata for a​ n​ b​ m​ c​ m​ d​ n​ . The push down automata will push "a" and "b" as the come as input symbol. When "c" came as input then for each "c" one "b" is popped from top of the stack. And when "d" will come as input symbol the top of stack will contain only a's so for every "d" one "a" is popped . In this way we can design a pushdown automata for a​ n​ b​ m​ c​ m​ d​ n​ .
So, option-C is correct answer.
Question 3
The transitive closure of a relation R on set A whose relation matrix

is
A
B
C
D
       Engineering-Mathematics       Set-Theory
Question 3 Explanation: 
The transitive closure of R is obtained by repeatedly adding (a,c) to R for each (a,b) ∈ R and (b,c) ∈ R.
Question 4
Consider the relation on the set of non-negative integers defined by ​ x ​ ≡ ​ y if and only if :
A
x mod 3=3 mod y
B
3 mod x≡3 mod y
C
x mod 3=y mod 3
D
None of the above
       Engineering-Mathematics       Set-Theory
Question 4 Explanation: 
A relation R is an equivalence relation if and only if it is reflexive, symmetric, and transitive.
1. The relation is reflexive: x mod 3 = x mod 3
2. The relation is symmetric: if x mod 3 = y mod 3, then y mod 3 = x mod 3
3. The relation is transitive: if x mod 3 = y mod 3, and y mod 3 = z mod 3, then x mod 3 = z mod 3
Question 5
Minimum number of individual shoes to be picked up from a dark room ( containing 10 pair of shoes) if we have to get at least one proper pair :
A
2
B
20
C
11
D
None of these
       Engineering-Mathematics       Combinatorics
Question 5 Explanation: 
→ There are 10 pair of shoes available in the dark room which means 20 individual shoes are available in the room.
→ If you pick shoes from one to ten individual shoes, there may be chance of getting same individual shoes.
→ There is no guarantee that getting one proper pair from 10 individual shoes.
→ If You pick 11 shoes, then there may chance of 10 individual shoes of same type and one individual shoe of another type. So we will get at least one proper pair shoe from 11 individual shoes.
Question 6
(101011)​ 2​ =(53)​ b​ , then ‘b’ is equal to :
A
4
B
8
C
10
D
16
       Digital-Logic-Design       Number-Systems
Question 6 Explanation: 
We are dividing binary number into 3 then
101 011
5 3
(101011)​ 2 = (53)​ 8
Suppose, we are dividing binary digits into 4 then
0010 1011
2 B
So, it is not hexadecimal number.
Question 7
The logic expression x’yz’+x’yz+xyz’+xyz reduces to :
A
x’z
B
xyz
C
y
D
yz
       Digital-Logic-Design       Boolean-Expression
Question 7 Explanation: 
We can use two methods to solve this problem.
Method-1 using K-Maps:

Method-2 using boolean simplification:
x’yz’+x’yz+xyz’+xyz
= x’y(z’+z)+xy(z’+z)
= x’y + xy
= y(x’+x)
= y
Question 8
Which of the following logic has the maximum fan out ?
A
RTL
B
ECL
C
NMOS
D
CMOS
       Digital-Logic-Design       Logic-Families
Question 8 Explanation: 
Emitter Coupled Logic (ECL)
The storage time is eliminated as the transistors are used in difference amplifier mode and are never driven into saturation.
1. Fastest among all logic families
2. Lowest propagation delay.
Complementary metal oxide semiconductor(CMOS)
The power dissipation is usually 10nW per gate depending upon the power supply voltage, output load etc.
1. Lowest power dissipation
2. Excellent noise immunity
3. High packing density
4. Wide range of supply voltage
5. Highest fan out among all logic families
Negative channel metal oxide semiconductor (NMOS)
It is a type of semiconductor that charges negatively. So that transistors are turned ON/OFF by the movement of electrons. In contrast, Positive channel MOS-PMOS works by moving electron vacancies. NMOS is faster than PMOS.
Resistor Transistor Logic (RTL)
Sometimes also transistor–resistor logic (TRL) is a class of digital circuits built using resistors as the input network and bipolar junction transistors (BJTs) as switching devices. RTL is the earliest class of transistorized digital logic circuit used; other classes include diode–transistor logic (DTL) and transistor–transistor logic (TTL).
Question 9
Which of the following binary number is the same as its 2’s complement :
A
1010
B
0101
C
1000
D
1001
       Digital-Logic-Design       Number-Systems
Question 9 Explanation: 
Option-A: 1010 convert into 2’s complement is
1010
1’s complement: 0101
2’s complement: 1
--------
0110
--------- Option-B: 0101 convert into 2’s complement is
0101
1’s complement: 1010
2’s complement: 1
--------
1011
---------
Option-C: 1000 convert into 2’s complement is
1000
1’s complement: 0111
2’s complement: 1
--------
1000
---------
Option-D: 1001 convert into 2’s complement is
1001
1’s complement: 0110
2’s complement: 1
--------
0111
---------
So, Option-C is correct answer.
Question 10
Identify the logic function performed by the circuit shown
A
Exclusive-OR
B
AND
C
Exclusive-NOR
D
NOR
       Digital-Logic-Design       Logic-Gates
Question 10 Explanation: 
Question 11
After 3 calls of the c function bug( ) below, the values of i and j will be :
int j=1;
bug( )
{
static int i=0; int j=0;
i++;
j++;
return (i);
}
A
i = 0, j = 0
B
i = 3, j = 3
C
i = 3, j = 0
D
i = 3, j = 1
       Programming       Storage-Classes
Question 11 Explanation: 
Step-1: Initially i=0 but given as static. The scope is lifetime.
Step-2: Call-1: i=1 and j=1
Call-2: i=2 and j=1 because ‘i’ is static ‘j’ is again become 0 when it starts new call.
Call-3: i=3 and j=1 because ‘i’ is static ‘j’ is again become 0 when it starts new call.
Note: A static ‘int’ variable remains in memory while the program is running.
Question 12
Find the output of the following “C” code :
main ( )
{
int x=20, y=35;
x= y++ + x++;
y= ++y + ++x;
printf (“%d, %d\n”, x,y);
}
A
55, 93
B
53, 97
C
56, 95
D
57, 94
E
56, 93
       Programming       Operator
Question 12 Explanation: 
Step-1: Here, we are using post increment for both x and y. In post increment the value assign first and update after assigning.
x= 35 + 20
y= 37 + 56 (In this statement, ‘y’ will become 36 before performing pre increment)
Step-2: Final x=56 and y=93
Note: They given wrong options. We are added correct option.
Excluded for evaluation.
Question 13
The data hiding is taken care by :
A
Abstraction
B
Encapsulation
C
Modularity
D
Inheritance
       Programming-in-c++       Properties
Question 13 Explanation: 
→ Abstraction is used for hiding the unwanted/important data and giving relevant data. → It only focus on what the object does instead of how it does it.
Question 14
If a data-item is declared as a protected access specifier then it can be accessed :
A
Anywhere in the program
B
By the base and derived classes
C
Only by base class
D
Only by derived class
       Programming-in-c++       Properties
Question 14 Explanation: 
If a data item is declared as a protected access specifier then it can be accessed by the base and derived classes.
Question 15
main( )
{
char *str = “abcde”;
printf (“%c”, *str);
printf (“%c”, *str++);
printf (“%c”, *(str++));
printf (“%s”, str);
}
The output of the above ‘C’ code will be :
A
a a c b c d e
B
a a c c c d e
C
a a b c d e
D
None of these
       Programming       Operator
Question 15 Explanation: 
The above program we are using post increment operators. In post increment the value assign first and update after assigning.
main( )
{
char *str = “abcde”;
printf (“%c”, *str); /* It returns character ‘a’ */
printf (“%c”, *str++); /* It returns character ‘a’ because it is used post increment*/
printf (“%c”, *(str++)); /* It returns character ‘b’ because the previous increment is update here and present also they given post increment, so it only returns ‘b’ */
printf (“%s”, str); /* It returns aabcde */
}
Question 16
An Entity - relationship diagram is a tool to represent :
A
Data model
B
Process model
C
Event model
D
Customer model
       Database-Management-System       ER-Model
Question 16 Explanation: 
A data model is an abstract model that organizes elements of data and standardizes how they relate to one another and to properties of the real world entities. For instance, a data model may specify that the data element representing a car be composed of a number of other elements which, in turn, represent the color and size of the car and define its owner. The "data model" may be defined using the entity-relationship data model.
Question 17
Which of the following tools is not required during system analysis phase of system development Life cycle ?
A
CASE Tool
B
RAD Tool
C
Reverse engineering tool
D
None of these
       Software-Engineering       Software-Development
Question 17 Explanation: 
→ ​ Reverse engineering tools​ are using debuggers. The debuggers are either user mode or Kernel mode.
→ ​ Computer aided software engineering​ (CASE) is the domain of software tools used to design and implement applications. CASE tools are similar to and were partly inspired by computer aided design (CAD) tools used for designing hardware products. CASE tools are used for developing high-quality, defect-free, and maintainable software.
→ ​ Rapid Application Development​ refers to a software development approach which puts less emphasis on planning and even design specifications, and more on rapid development and quick feedback. Prototypes are rapidly delivered to users to ensure they’re directly involved in feedback and development. There are also tools for collecting data, designing personal workflows, and setting up unique rules for each new application.
Question 18
A black hole in a DFD is a :
A
A data store with no inbound flows
B
A data store with only in bound flows
C
A data store with more than one in bound flow
D
None of these.
       Software-Engineering       Software-Development
Question 18 Explanation: 
Black Hole: A processing step may have input flows but no output flows.
Miracle: A processing step may have output flows but now input flows.
Grey Hole: A processing step may have outputs that are greater than the sum of its inputs - e.g., its inputs could not produce the output shown.
Question 19
Multi-valued dependency among attribute is checked at which level ?
A
2 NF
B
3 NF
C
4 NF
D
5 NF
       Database-Management-System       Normalization
Question 19 Explanation: 
→ Multivalued dependency among attribute is checked in 4NF.
→ A relation is in 4NF if it is in BCNF and has no multivalued dependency.
→ A relation will contain Multivalued dependency if there exists a dependency A → B such that for a single value of A, multiple values of B exists.
Question 20
A WINDOW into a portion of a database is :
A
Schema
B
View
C
Query
D
Data Dictionary
       Database-Management-System       Databases
Question 20 Explanation: 
→ A view in database returns a portion of database based on the condition given in the SQL query.
→ View of a database gives the updated data stored in the database. A view returns a virtual view of database. It can join and simplify multiple tables into a single virtual table.
Question 21
What is the time required to insert an element in a stack with linked implementation ?
A
O (log​ 2​ n)
B
O (n)
C
O (n log​ 2​ n)
D
O (1)
       Data-Structures       Queues-and-Stacks
Question 21 Explanation: 
Question 22
Which of the following statement is false ?
A
Every tree is a bipartite graph
B
A tree contains a cycle
C
A tree with n nodes contains n-1 edges
D
A tree is a connected graph
       Data-Structures       Trees
Question 22 Explanation: 
A tree never contains cycles. If it contains a cycle, we are calling as graph but not tree.
Note: Minimum 1 edge and maximum n-1 edges.
Question 23
In the balanced binary tree given below, how many nodes will become unbalanced when a node is inserted as a child of the node “g” ?
A
1
B
3
C
7
D
8
       Data-Structures       Binary-Trees
Question 23 Explanation: 

a, c, d are going to unbalance.
Question 24
If the postfix form of a string is ABC+ - D*, the actual string is :
A
(A-(B+C))*D
B
((A-B)+C)*D
C
((A+B)-C)*D
D
(A+(B-C))*D
       Data-Structures       Queues-and-Stacks
Question 24 Explanation: 
Question 25
The algorithm that will efficiently sort an array that is nearly sorted except for the interchange of some adjacent pairs of numbers like : { 1, 3, 2, 5, 4, 6} is :
A
Quick sort
B
Bubble sort
C
Merge sort
D
Selection sort
       Data-Structures       Arrays
Question 25 Explanation: 
If we are using quick sort to sort a nearly sorted/sorted elements will give worst case time complexity. Here the number interchanges are more.
Bubble sort will give best complexity, when the array is very sorted. Here the number interchanges are very less.
Merge sort will will gives best time complexity but not like bubble in this case. Here the number interchanges are more.
Selection sort will always gives worst performance, whether it is sorted order or not.
Question 26
Which of the following are Data link layer standard ?
(1) Ethernet
(2) HSSI
(3) Frame Relay
(4) 10base T
(5) Token ring
A
1, 2
B
1, 3, 5
C
1, 3, 4, 5
D
1, 2, 3, 4, 5
       Computer-Networks       Data-Link-Layer
Question 26 Explanation: 
Except HSSI, all are belongs to data link layer.
The High-Speed Serial Interface (HSSI) is a differential ECL serial interface standard developed by Cisco Systems and T3plus Networking primarily for use in WAN router connections. It is capable of speeds up to 52 Mbit/s with cables up to 50 feet (15 m) in length.
Question 27
Which type of Bridge would be used to connect an Ethernet Segment with a token ring Segment ?
A
Transparent Bridge
B
Source-Route Bridge
C
Translation Bridge
D
None of these
       Computer-Networks       Ethernet
Question 27 Explanation: 
Transparent bridge:​ A transparent bridge is a bridge in which the stations are completely unaware of the bridge's existence.
Source-Route Bridge:​ To prevent loops in a system with redundant bridges is to use source routing bridges. A transparent bridge's duties include filtering frames, forwarding, and blocking.
In a system that has source routing bridges, these duties are performed by the source station and, to some extent, the destination station. Theoretically a bridge should be able to connect LANs using different protocols at the data link layer, such as an Ethernet
Segment with a token ring Segment but practically it can not connect two LANs with different protocols. One of the reasons of this is Maximum data size. If an incoming frame's size is too large for the destination LAN, the data must be fragmented into several frames. The data then need to be reassembled at the destination. However, no protocol at the data link layer allows the fragmentation and reassembly of frames. The other issues because of which a bridge is not able to connect LANs using different protocols are data rate, bit order, security, multimedia support.
So, the answer is Option(D)
Question 28
Which type of links are used for a connection between two DTE devices ?
A
X.21
B
Frame Relay
C
ATM
D
Modem
       Computer-Networks       Topologies
Question 28 Explanation: 
Data terminal equipment (DTE)​ is an end instrument that converts user information into signals or reconverts received signals. These can also be called tail circuits. A DTE device communicates with the data circuit-terminating equipment (DCE). Usually, the DTE device is the terminal (or a computer emulating a terminal), and the DCE is a modem. A DTE is the functional unit of a data station that serves as a data source or a data sink and provides for the data communication control function to be performed in accordance with the link protocol.
Question 29
Which protocol is used to encapsulate a data pocket created of a higher OSI model layer ?
A
HDLC
B
SDLC
C
LAPB
D
LAPD
       Computer-Networks       OSI-TCP-layers
Question 29 Explanation: 
Link Access Procedures, D channel(LAPD)​ is part of the network's communications protocol which ensures that messages are error free and executed in the right sequence.
LAPD is the second layer protocol on the ISDN protocol stack in the D channel (the ISDN channel in which the control and signalling information is carried).
LAPD standards are specified in ITU-T Q.920 and Q.921. Its development was heavily based on High-Level Data Link Control.
Question 30
What is the correct subnet mask to use for a class-B address to support 30 Networks and also have the most hosts possible ?
A
255​ .​ 255​ .​ 255​ .​ 0
B
255​ .​ 255​ .​ 192​ .​ 0
C
255​ .​ 255​ .​ 240​ .​ 0
D
255​ .​ 255​ .​ 248​ .​ 0
       Computer-Networks       IP-Adress
Question 30 Explanation: 

→ In class-B addressing NID’s are having 16-bits and host IDs are having 16 bits.
Step-1: Given data, to support for 30 networks is required. So number of bits taken from host ID to uniquely identify each of these network is (log 30/ log 2) i.e. 5-bits.
Step-2: NID’s are required for network is 21 bits and host id is 11-bits.
Step-3: Subnet mask of a network have NID as all 1's and Host ID as all 0's.
Network subnet mask is : 11111111. 11111111. 11111000. 00000000
Decimal representation of above subnet mask is : 255.255.248.0
Question 31
Which of the statements related to Compilers is wrong ?
A
Lexical analysis is breaking the input into tokens
B
Syntax analysis is for parsing the phrase
C
Syntax analysis is for analyzing the semantic
D
None of these
       Compiler-Design       Compilers
Question 31 Explanation: 
TRUE: Lexical analysis is breaking the input into tokens
TRUE: Syntax analysis is for parsing the phrase
FALSE: Syntax analysis is for analyzing the semantic. For analysing semantics we are using semantic analysis but not syntax analysis
Question 32
Which of the following is the most general phase-structured grammar ?
A
Regular
B
Context - Sensitive
C
Context free
D
None of these
       Theory-of-Computation       Context-Sensitive-Grammar
Question 32 Explanation: 
→ Phrase structure grammars(or) Phase structure grammars are also known as constituency grammars. The defining trait of phrase structure grammars is thus their adherence to the constituency relation, as opposed to the dependency relation of dependency grammars.
→ Most general phase structured grammar is context sensitive grammar
Question 33
Which activity is not included in the first pass of two pass assemblers ?
A
Build the symbol table
B
Construct the machine code
C
Separate mnemonic opcode and operand fields.
D
None of these
       Theory-of-Computation       Context-Sensitive-Grammar
Question 33 Explanation: 
Two Pass Assemblers:
Pass-1:
1. Assign addresses to all statements in the program
2. Save the values assigned to all labels for use in Pass2
3. Perform some processing of assembler directives
Pass-2:
1. Assemble instructions Generate data values defined by BYTE,WORD
2. Perform processing of assembler directives not done in Pass 1
3. Write the object program and the assembly listing
Question 34
The dynamic binding occurs during the :
A
Compile time
B
Run time
C
Linking time
D
Pre-processing time.
       Compiler-Design       Run-Time-Environment
Question 34 Explanation: 
The dynamic binding occurs during the run time. The method being called upon an object or the function being called with arguments is looked up by name at runtime.
Question 35
Symbol Table can be used for :
A
Checking type compatibility
B
Suppressing duplication of error message
C
Storage allocation
D
All of these
       Compiler-Design       Symbol-Table
Question 35 Explanation: 
A symbol table can be used for
1. To store the names of all entities in a structured form at one place.
2. To verify if a variable has been declared.
3. To implement type checking, by verifying assignments and expressions in the source code are semantically correct.
4. To determine the scope of a name (scope resolution).
Question 36
Moving Process from main memory to disk is called :
A
Caching
B
Termination
C
Swapping
D
Interruption
       Operating-Systems       Memory-Management
Question 36 Explanation: 
Swapping is a mechanism in which a process can be swapped/moved temporarily out of main memory to a backing store , and then brought back into memory for continued execution.
Question 37
The principle of Locality of reference justifies the use of :
A
Virtual memory
B
Interrupts
C
Cache memory
D
Secondary memory
       Computer-Organization       Cache
Question 37 Explanation: 
→ The principle of Locality of reference justifies the use of cache memory. The principle of locality, is the tendency of a processor to access the same set of memory locations repetitively over a short period of time.
→ Locality is merely one type of predictable behavior that occurs in computer systems. Systems that exhibit strong locality of reference are great candidates for performance optimization through the use of techniques such as the caching, prefetching for memory and advanced branch predictors at the pipelining stage of a processor core.
Question 38
Banker’s algorithm is for.
A
Deadlock Prevention
B
Deadlock Avoidance
C
Deadlock Detection
D
Deadlock creation
       Operating-Systems       Deadlock
Question 38 Explanation: 
Banker’s algorithm is for deadlock avoidance.
Question 39
Which is the correct definition of a valid process transition in an operating system ?
A
Wake up : Ready → Running
B
Dispatch : Ready → Running
C
Block : Ready → Running
D
Timer run out : Ready → Blocked
       Operating-Systems       Process-State-Transition-Diagram
Question 39 Explanation: 
Dispatcher is also called as short term scheduler. Dispatcher is responsible for loading the selected process by short term scheduler on the CPU(Ready to Running State). It is involved in the CPU-scheduling function is the dispatcher, which is the module that gives control of the CPU to the process selected by the short-term scheduler. It receives control in kernel mode as the result of an interrupt or system call.
Question 40
Which of the following is not an Unix Command ?
A
Whoami
B
wc
C
ls
D
put
       Operating-Systems       UNIX-Operating-System
Question 40 Explanation: 
→ whoami: It lists the account name associated with the current login.
→ wc: It displays total word counts.
→ ls: It displays list of all files in a current folder.
**** There is no command called put.
Question 41
The capability maturity model (err) defines 5 levels :
A
a-(i), b-(ii), c-(iii), d-(iv), e-(v)
B
a-(iv), b-(iii), c-(ii), d-(i), e-(v)
C
a-(v), b-(i), c-(iii), d-(ii), e-(iv)
D
a-(v), b-(ii), c-(i), d-(iii), e-(iv)
Question 41 Explanation: 
CMM stands for Capability Maturity Model is a process model which specifies the process improvement approach in software development.
CMM levels:
1. Initial
2. Repeatable
3. Defined
4. Managed
5. Optimizing
Question 42
Which one of the following is not a software process model ?
A
Linear sequential model
B
Prototyping model
C
The spiral model
D
COCOMO model
       Software-Engineering       Types-of-Models
Question 42 Explanation: 
The Constructive Cost Model (COCOMO) is a procedural software cost estimation model but not software process model. Linear sequential,prototype and spiral models are software process models.
Question 43
System Development Life-cycle has following stages :
(I) Requirement analysis
(II) Coding
(III) Design
(IV) Testing
Which option describes the correct sequence of stages ?
A
III, I, IV, II
B
II, III, I, IV
C
I, III, IV, II
D
None of the above
       Software-Engineering       Software-Development
Question 43 Explanation: 
Question 44
Which one is measure of software complexity ?
A
Number of lines of code (LOC)
B
Number of man years
C
Number of function points (FP)
D
All of the above
E
Both LOC and FP
       Software-Engineering       software-complexity
Question 44 Explanation: 
→ A function point is a "unit of measurement" to express the amount of business functionality an information system (as a product) provides to a user. Function points are used to compute a functional size measurement (FSM) of software.
→ Lines of code (LOC) is a software metric used to measure the size of a computer program by counting the number of lines in the text of the program's source code.
Question 45
Which type of coupling is least preferred ?
A
Content coupling
B
Data coupling
C
Control coupling
D
Common coupling
       Software-Engineering       Coupling-and-Cohesion
Question 45 Explanation: 
Data coupling is the weakest coupling and it is most desirable coupling in a software, as a low degree of coupling is good for a software.
Coupling in the order from highest(least desirable) to the least (most desirable)
I. Content coupling
II. Common coupling
III. Control coupling
IV. Stamp coupling
V. Data coupling
Question 46
PVM and MPI Library functions are implemented on the top of the :
A
Universal Message Passing (UMS)
B
Network Interface Driver (NID)
C
Media Access Control (MAC)
D
None of these
       Computer-Networks       Distributed-Computing
Question 46 Explanation: 
PVM and MPI are the most used tools for parallel programming.
Message Passing Interface(MPI):​ A fixed set of processes is created at program initialization, one process is created per processor
Parallel Virtual Machine(PVM):​ It Is a software package that allows a heterogeneous collection of workstations (host pool) to function as a single high performance parallel machine (virtual)
Question 47
The frequency reuse plan is divided into cell grouping using how many cells, where the number of cells equals N ?
A
3
B
10
C
7
D
21
       Data-Communication       Cellular-Networks
Question 47 Explanation: 
The cluster size N = 7 and the frequency reuse factor is 1/7 since each cell contains one-seventh of the total number of available channels.
Total cells=7*3
=21
Frequency reuse concept, cells with the same letter use the same set of frequencies. A cell cluster is outline in blue color and replicated over the converge area.
Question 48
Which interim standard describes inter-switching networking ?
A
IS - 54
B
IS - 95
C
DS - 45
D
ANSI - 41
       Data-Communication       Cellular-Networks
Question 48 Explanation: 
→ Interim Standard 95 (IS-95) was the first ever CDMA-based digital cellular technology.
→ The IS-95 standards describe an air interface, a set of protocols used between mobile units and the network.
→ IS-95 is widely described as a three-layer stack, where L1 corresponds to the physical (PHY) layer, L2 refers to the Media Access Control (MAC) and Link-Access Control (LAC) sublayers, and L3 to the call-processing state machine.
Question 49
Theoretically, how many 1.25 MHz Carriers are there in a CDMA cell ?
A
18
B
22
C
9
D
64
       Data-Communication       Cellular-Networks
Question 49 Explanation: 
→ In CDMA, multiple users share a 1.25 MHz channel by using orthogonal spreading codes (Walsh codes)
→ IS-95a standard designed for AMPS cellular band
→ Each cellular provider is allocated 25 MHz spectrum and ten 1.25-MHz CDMA duplex channels if A AMPS Band provider, 9 if B band provider
Question 50
Another name of IEEE 802.11a is :
A
WECA
B
Fast Ethernet
C
Wi-Fi 5
D
802​ .​ 11g
       Computer-Networks       IEEE-802.11
Question 50 Explanation: 
It operates in the 5 GHz band with a maximum net data rate of 54 Mbit/s, plus error correction code, which yields realistic net achievable throughput in the mid-20 Mbit/s.
802.11b typically has a higher range at low speeds (802.11b will reduce speed to 5.5 Mbit/s or even 1 Mbit/s at low signal strengths). 802.11a also suffers from interference.
There are 50 questions to complete.