SOLUTION

The NIC manufacturer assigns a unique physical address to each NIC card.  This physical address is known as MAC address.

SOLUTION

The NIU (Network Interface Unit) is a device that is attached to each of the workstations and server. It facilitates and manages a connection between two different physical medium in order to create a network connection.

SOLUTION

Communication protocol used by internet is known as TCP/IP. The TCP part is responsible for dividing the file into packets on the source computer. The IP part is responsible for handling the address of destination computer.

SOLUTION

In internet, many smaller networks are connected and allow all the computers to exchange information with each other. This is possible through rules set for communication, called protocols.

SOLUTION

ARPANET stands for Advanced Research Project Agency Network. The goal of this project was to connect computers at different universities and U.S. defense.

SOLUTION

In internet, most computers are connected to smaller networks, which in turn are connected through gateways to the internet backbone.

SOLUTION

Although the bus topology is very simple, but in this topology fault detection is very difficult.

SOLUTION

The main disadvantage of the optical fiber cable is that it is very costly.Even though the raw materials for optical fibers are cheap and abundant, but still it is more expensive per metre than copper.

SOLUTION

Wide Area Network (WAN) is a computer network that covers a broad area (i.e., any network whose communication links cross metropolitan, regional, or national boundaries).

SOLUTION

Archie is a tool for indexing FTP archives, allowing people to find specific files. It is considered to be the first Internet search engine.

SOLUTION

NFS (Network File System) allows computers to share files across a network.

SOLUTION

A server may be dedicated or non-dedicated. Dedicated servers are used only as a server, not as a workstation. Non-dedicated servers are used both as a server and a workstation.

SOLUTION

WAIS (Wide Area Information Servers) is an Internet system in which specialized subject databases are created at multiple server locations, keeps track by a directory of servers at one location, and make accessible for searching by users with WAIS client programs.

SOLUTION

A Karnaugh Map is a graphical way of minimizing a boolean expression(Maxterms or Minterms).

SOLUTION

Circuits using NAND and NOR are popular as they are easier to design and therefore cheaper. Functions of other gates can easily be implemented using NAND and NOR gates. For this reason they are called universal gates.

SOLUTION

According to the Principle of Duality, the dual of any statement in Boolean algebra is obtained by interchanging '+' and '.' and simultaneously inter-changing 0 and 1 in the statement.  In this way, starting with a boolean expression, we get another boolean expression.  
For example:
(i) The dual of the statement

                 (x . 1 )(0 + x') = 0       is       (x + 0)(1 . x') = 1              

(ii) The dual of the statement

            (x + y)(y + z) = x.z + y    is        x.y + y.z = (x + z).y

SOLUTION

A Tautology is any logical statement that always results in True.  Example, the statement – “Malaria is dangerous”  is always true.  
A Fallacy is a statement that always results in False. Example – “Toxic waste is easy to store”  - is always false.

SOLUTION

Logical operations involve the use of three operators – NOT, AND and OR.  NOT simple negates a value.  It uses one operand.  For Example - a)  Not True (which means, False  as True and False are the only possible values)  b)  Knowing English AND French (means someone who knows both English AND French)  c) Knowing English OR French (means someone who knows either English or French).

SOLUTION

Boolean Algebra is a branch of mathematics, somewhat similar to, but different from ordinary algebra. It is a system of symbols and operators that apply to logical problems. It is an algebra in which elements can take only one of two values 0 or 1 that represent false or true and are subject to operations based on AND, OR and NOT.

SOLUTION

The XNOR Gate is logically equivalent to an invertor XOR Gate  i.e. XOR gate followed up by a NOT Gate(inventor). The XNOR Gate Produces 1 (high) Output when the input combination has even number of one 1's.    

SOLUTION

In Boolean algebra, 0 and 1 (False and True) are the only values allowed.  The meaning and application of logical addition (+), logical multiplication (.),  is very different from addition and multiplication in ordinary algebra.  Other operators like /, * are not used.  The basic postulates on which boolean expressions are based are not applicable in ordinary algebra. There are certain laws (like Indempotence law and Absorption law) and theorems like, De Morgan’s theorems that apply to boolean algebra.

SOLUTION

A Minterm is a product of all the literals (inputs) into the system. Each literal may be with or without the bar (i.e. complemented). 
A Maxterm is a sum of all the literals (inputs) into the system. The literals may be with or without the bar (i.e. complemented).

SOLUTION

Output is given below :-

Canonical Sum_of_Products expression as sum of minterms

= A’B’C’D’ + A’B’CD’ + A’BC’D + A’BCD + AB’C’D’ + AB’CD’ + ABC’D + ABCD

Canonical Product_of_Sums  expression as sum of maxterms

SOLUTION

The truth table is as follows:

The truth table shows the two columns X and X.(X+Y) to be identical.

SOLUTION

A Boolean expression that is composed of only Minterms or Maxterms is said to be in Canonical form. Thus, we can have expressions in Canonical Sum_of _Products form or Canonical Product_of_Sums form.

SOLUTION

Wherever a literal is missing in a term, multiply it with the (missing literal + its negated missing literal) 
   
YZ + X’ Y    =  (X + X’)YZ + X’Y(Z + Z’) 
                 = XYZ + X’YZ + X’YZ + X’YZ’ 
                 =  XYZ + X’YZ + X’YZ’

SOLUTION

Wherever a literal is missing in a term, add (missing literal . negated missing literal) 
  (A + C).(C + D)  =  (A + C + DD’).(AA’ + C + D)

                         = (A+C+D)(A+C+D’)(A+C+D)(A’+C+D)   as (X+YZ)=(X+Y)(X+Z)

SOLUTION

A binary decision is one that results in either a Yes or a No.
Consider the statements below –

a)  Is Mumbai an important city of India?

b)  Is the train on time?          

c)  Is the library open? 

These can be answered with a yes or no, and are called logical statements. The result, True or False is called truth value.

SOLUTION

X’YZ’  +  XY’Z’ + XYZ = F

SOLUTION

a)Complement of X’Y + XY’ + X’Y’ 
                       = (X’Y + XY’ + X’Y’)’

                       = (X’Y)’ . (XY’)’ . (X’Y’)’                as (X+Y+Z)’ = X’.Y’.Z’

                       = (X’’ + Y’) . (X’+ Y’’) . (X’’ + Y’’)    as (X.Y)’ = X’+Y’

                       = (X+Y’).(X’+Y).(X+Y)

b) Complement of  (B+D’)(A+C’)

                             = ((B+D’)(A+C’) )’

                             = (B+D’)’ + (A+C’)’

                             =  B’D’’  +  A’C’’

                             =  B’D   + A’C

SOLUTION

Steps are:–

a) Derive the simplified POS expression

b) Draw the circuit diagram using NOT, AND and OR gates

c) Replace NOT, AND and OR gates with NOR gates

NOR gates are suitable for expressions in POS form

SOLUTION

Truth Table for 3 inputs, X, Y and Z is -

F = m₃ + m₅ + m₆

Marking the minterms in the Karnaugh map, we get the simplified SOP expression -
F = X’YZ + XY’Z + XYZ’

SOLUTION

Logic gates are digital circuits constructed from diodes, transistors, and resistors that produce an output, from some given inputs.
NOT gates - They are also called Inverters. The NOT operation can be performed on a single input. For example, if the variable A is subjected to the NOT operation, the result x can be expressed as X = where represents the NOT operation.

The truth table of the NOT operation is as follows:

AND gates - The AND gate uses 2 or more inputs to produce a single output. The resultant output 1 occurs only then all of the inputs are 1.

Truth Table for 2 input AND Gate

The output A.B can be written as AB, without the ‘.’ symbol.

OR gates - The OR gate uses 2 or more inputs to produce a single output. The result produced is 1 when any of the inputs is 1. The result 0 is produced only when all the input variables are 0.

Truth Table for OR Gate

SOLUTION

Minterm is a product of all the literals(with or without the bar) within the logic system.

SOLUTION

Tautology is a statement which is always true.

SOLUTION

The AND gate can have two or more than two input signals and produce an output signal. when all the inputs are 1 i.e. high then the output is 1 otherwise output is 0 only.

SOLUTION

The OR gate is a digital logic gate that implements logical disjunction.

SOLUTION

The NOT operator operates on single variable and the operation performed by NOT operator is called complementation.

SOLUTION

In digital logic, an inverter or NOT gate is a logic gate which implements logical negation.

SOLUTION

In a Karnaugh map, the boolean variables are transferred (generally from a truth table) and ordered according to the principles of Gray code in which only one variable changes in between the squares.

SOLUTION

A karnaugh map is an array of squares. A 3-variable K-map has 8 squares and 4-variable K-map will have 16 squares.

SOLUTION

A maxterm is a Boolean expression resulting in a 0 for the output of a single cell expression and 1s for all other cells in the Karnaugh map or truth table.

SOLUTION

A minterm is a Boolean expression resulting in 1 for the output of a single cell and 0s for all other cells in a Karnaugh map or truth table.

SOLUTION

DeMorgan's theorem may be thought of in terms of breaking a long bar symbol. When a long bar is broken, the operation directly underneath the break changes from addition to multiplication or vice versa and the broken bar pieces remain over the individual variables.

SOLUTION

A logic gate performs a logical operation on one or more logic inputs and produces a single logic output.

SOLUTION

A half adder can add two bits. It has two inputs, generally labelled A and B and two outputs, the sum S and carry C.

SOLUTION

OR operator is used to perform a logical disjunction on two expressions.

SOLUTION

AND operator is used to perform a logical conjunction on two expressions.

SOLUTION

The Karnaugh map, also known as a Veitch diagram (KV-map or K-map for short), is a method to simplify Boolean algebra expressions. The K-map reduces the need for extensive calculations by taking advantage of humans' pattern-recognition capability, permitting rapid identification and elimination of potential race hazards.

SOLUTION

Logic problems are binary decisions and boolean algebra effectively deals with these binary values. The decision which results into either YES (TRUE) or NO (FALSE) is called a BINARY DECISION.

SOLUTION

If result of any logical statement or expression is always TRUE or 1, it is called tautology.

SOLUTION

George Boole, was an Englishman who invented Boolean algebra. His concepts are well known today in the field of mathematical logic. He gave the operators 'And, Or, and Not'  used to connect conditions. His major book on symbolic logic identified the concept of "Boolean Logic" in "The Mathematical Analysis of Logic" in 1847. He authored "An Investigation of the Laws of Thought" in 1854. Here, he described what the computer industry now calls cybernetics.

SOLUTION

A Truth Table is a table that gives all possible values of logical variables in all possible combinations, and their corresponding results.

SOLUTION

The boolean expression composed entirely either of Minterms or Maxterms is referred to as Canonical Expression. Canonical expression can be represented in following two forms : Sum-of-Products (S-O-P) form and Product-of-sums (P-O-S) form.

SOLUTION

If the value of a variable is 1, then its complement is added otherwise the variable is added as it is.

SOLUTION

For example, X+Y can be expressed as the sum of several products, each of the product containing letters X and Y. These products are called minterms and each contains all the literals with or without the bar.

SOLUTION

Karnaugh map or K-map is a graphical display of the fundamental products in a truth table. For a function of n variables, there would be a map of 2ⁿ squares, each representing a minterm.    

SOLUTION

Gates are digital (two-state) circuits because the input and output signals are either low voltage (denotes 0) or high voltage (denotes 1). Gates are often called logic circuits because they can be analyzed with boolean algebra.

SOLUTION

Universal gates are the ones which can be used for implementing any gate like AND, OR and NOT, or any combination of these basic gates. NAND and NOR gates are universal gates.

SOLUTION

In Boolean algebra, any boolean function can be expressed in a canonical form using the dual concepts of minterms and maxterms.

SOLUTION

A bitwise OR takes two bit patterns of equal length and produces another one of the same length by matching up corresponding bits (the first of each, the second of each and so on) and performing the logical inclusive OR operation on each pair of corresponding bits.

SOLUTION

In digital logic, an inverter or NOT gate is a logic gate which implements logical negation.

SOLUTION

For a function of n variables, there would be a map of 2ⁿ squares.

SOLUTION

If result of any logical statement or expression is always TRUE or 1, it is called tautology.

SOLUTION

AND Operator performs another important operation of boolean algebra called logical multiplication and the symbol for AND operation is (.) dot. Thus X.Y will be read as X and Y.  OR operator denotes operation called logical addition and the symbol used for it is '+'. The + symbol, therefore, does not have the 'normal' meaning but it is a logical addition or logical OR symbol. The X+Y can be read as X OR Y.

SOLUTION

If result of any logical statement or expression is always TRUE or 1, it is called tautology and if the result is always FASLE or 0 it is called fallacy.

SOLUTION

A fallacy is an argument which provides poor reasoning in support of its conclusion.

SOLUTION

In propositional logic, tautology is a propositional formula that is true under any possible valuation of its propositional variables.

SOLUTION

Boolean algebra (or Boolean logic) is a logical calculus of truth values, developed by George Boole in 1840s.

SOLUTION

The XOR gate (sometimes EOR gate) is a digital logic gate that implements exclusive disjunction.

SOLUTION

The Karnaugh map, also known as a Veitch diagram (KV-map or K-map for short), is a method to simplify Boolean algebra expressions.

SOLUTION

A bitwise OR takes two bit patterns of equal length and produces another one of the same length by matching up corresponding bits (the first of each, the second of each, and so on) and performing the logical inclusive OR operation on each pair of corresponding bits.

SOLUTION

A MAXTERM is a sum of all the literals (with or without the bar) within the logica system.

SOLUTION

Unguided media is also called wireless where any phyisical path is not used for transmission.

SOLUTION

Guided media is that where we use any path for communication like cables(coaxial,fibre optic,twisted pair)etc.

SOLUTION

The word noise means unwanted sound or noise pollution.

SOLUTION

Attenuation (in some contexts also called extinction) is the gradual loss in intensity of any kind of flux through a medium.

SOLUTION

In telecommunications, message switching was the precursor of packet switching, where messages were routed in their entirety, one hop at a time.

SOLUTION

In telecommunications, a circuit switching network is one that establishes a circuit (or channel) between nodes and terminals before the users may communicate, as if the nodes were physically connected with an electrical circuit.

SOLUTION

Packet switching is a network communications method that groups all transmitted data, irrespective of content, type, or structure into suitably-sized blocks, called packets. The network over which packets are transmitted is a shared network which routes each packet independently from all others and allocates transmission resources as needed.

SOLUTION

A local area network (LAN) is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport. The defining characteristics of LANs, in contrast to wide-area networks (WANs), include their usually higher data-transfer rates, smaller geographic range, and lack of a need for leased telecommunication lines.

SOLUTION

A computer network that spans a relatively large geographical area. Typically, a WAN consists of two or more local-area networks (LANs).

SOLUTION

Network topology is the study of the arrangements or mapping of the elements of a network, especially the physical and logical inter-connection between nodes.

SOLUTION

A MAN is optimised for a larger geographical area unlike LAN, ranging from several blocks of buildings to entire cities.

SOLUTION

In Internet, most computers are connected to smaller networks which in turn are connected through gateways to the Internet backbone.

SOLUTION

In a ring network, data travels in one direction, passing through each machine until it reaches its destination device.

SOLUTION

Because everything is linked in a large network, viruses can quickly spread through a network.

SOLUTION

Devices like printers can be shared easily on a network.

SOLUTION

Single communication channel is a communication network which uses broadcasting for communication between its nodes.

SOLUTION

Point-to-point telecommunication generally refers to a connection restricted to two end-points.

SOLUTION

The Fiber Distributed Data Interface (FDDI) topology is a ring with two counter-rotating rings for reliability and with no hubs.

SOLUTION

A backbone is a part of computer network infrastructure that interconnects various pieces of network, providing a path for the exchange of information between different LANs or sub-networks.

SOLUTION

Ethernet network is the most commonly used technology whenever we have to set up a local area network (LAN). It is based on the IEEE 802.3 standard.

SOLUTION

If there is any error in any line then interpreter reports it at the same time and program execution cannot resume until the error is rectified.

SOLUTION

Assembler is used because the computer does not understand any language other than its own machine language.

SOLUTION

Optical fibre is a glass or plastic fibre that carries light along its length. These are used in fibre optic communication, which permits transmission over long distances and at higher bandwidth.

SOLUTION

NIC stands for network interface controller. It is designed to allow computer to communicate over a computer network.

SOLUTION

Internet society set the rules and standards for accessing the data on the internet.

SOLUTION

SCSI is a set of standards for physically connecting and transferring data between computer and peripheral devices. It is used in hard disks, tape drives, scanners and CD drives.

SOLUTION

A bit is a binary unit taking values 0 and 1. Apart from this, it is also used as unit of measurement, the information capacity of one binary digit.