Chapter 1

Introduction
1.What do you mean by data and Information?

Or: What are the differences between data and information?

Or: What are the Relations between data and information?

Or: How data transform into information?

Ans: Data: Data are the names given to basic facts such as names and numbers.

Example: Unit price, quantity sold, times, dates, products name, addresses, tax codes etc.

Information: Information is processed data, that is information is data which have been
converted into a more useful form.

For example, Total price = Unit price × Quantity sold

Here, Total price is information and unit price, quantity sold are data.

Figure 1.1 Relations between data and information

From the figure we see that at first data then processing and then finally information produced.

2.What is computer? Who is the inventor of computer?

 A computer is a programmable machine that receives input, stores and manipulates data, and
provides output in a useful format.
 A computer is a machine that manipulates data according to a set of instructions.
 A computer is a machine for performing calculations automatically
 Figure 1.2 (a) Computer System (b) Charles Babbage

Inventor of Computer: Englishman Charles Babbage who is known as "the father of the Computer". This
machine used the decimal numbers system and was powered by cranking a handle. The British government
first financed the project but then later cut off support. Babbage went on to design his much more general
analytical engine but later returned and produced an improved design (his "Difference Engine No. 2")
between 1834 and 1869.

3.What are the characteristics of computer?

Ans: The characteristics of computer are:

 Speed
 Accuracy
 Diligence
 Versatility
 Power of Remembering
 No IQ
 No Feeling
 Storage

4.Write the brief history of computer?

Ans: History of Computer : History of computer could be traced back to the effort of man to count
large numbers. This process of counting of large numbers generated various systems of numeration like
Babylonian system of

numeration, Greek system of numeration, Roman system of numeration and Indian system of numeration.
Out of these the Indian system of numeration has been accepted universally. It is the basis of modern
decimal system of numeration (0, 1, 2, 3, 4, 5, 6, 7, 8, 9). Later you will know how the computer solves all
calculations based on decimal system. But you will be surprised to know that the

computer does not understand the decimal system and uses binary system of numeration for processing.

We will briefly discuss some of the path-breaking inventions in the field of computing devices.

 Calculating Machines

It took over generations for early man to build mechanical devices for counting large numbers. The first
calculating device called ABACUS was developed by the Egyptian and Chinese people.

The word ABACUS means calculating board. It consisted of sticks in horizontal positions on which were
inserted sets of pebbles. A modern form of ABACUS is
given in Fig. 1.2. It has a number of horizontal bars each
having ten beads. Horizontal bars represent units, tens,
hundreds, etc. Figure 1.3
Abacus Computer

 Napier’s bones

English mathematician John Napier built a mechanical device for the purpose of multiplication in 1617 A
D. The device was known as Napier’s bones.
  Slide Rule

English mathematician Edmund Gunter developed the slide rule. This machine could perform operations
like addition, subtraction, multiplication, and division. It was widely used in Europe in 16th century.

 Pascal's Adding and Subtractory Machine

You might have heard the name of Blaise Pascal. He developed a machine at the age of 19 that could add
and subtract. The machine consisted of wheels, gears and cylinders.

 Leibniz’s Multiplication and Dividing Machine

The German philosopher and mathematician Gottfried Leibniz built around 1673 a mechanical device that
could both multiply and divide.

 Babbage’s Analytical Engine

It was in the year 1823 that a famous English man Charles Babbage built a mechanical machine to do
complex mathematical calculations. It was called difference engine. Later he developed a general-purpose
calculating machine called analytical engine. You should know that Charles Babbage is called the father of
computer.

 Mechanical and Electrical Calculator

In the beginning of 19th century the mechanical calculator was developed to perform all sorts of
mathematical calculations. Up to the 1960s it was widely used. Later the rotating part of mechanical
calculator was replaced by electric motor. So it was called the electrical calculator.

 Modern Electronic Calculator

The electronic calculator used in 1960 s was run with electron tubes, which was quite bulky. Later it was
replaced with transistors and as a result the size of calculators became too small.

The modern electronic calculator can compute all kinds of mathematical computations and mathematical
functions. It can also be used to store some data permanently. Some calculators have in-built programs to
perform some complicated calculations.

Figure 1.4 Vacuum tube, transistor, IC

5.What are the computer generations?

Or: Describe computer generations.

Ans: Computer generations:

We know that the evolution of computer started from 16th century and resulted in the form that we see
today. The present day computer, however, has also undergone rapid change during the last fifty years.
This period, during which the evolution of computer took place, can be divided into five distinct phases
known as Generations of Computers. Each phase is distinguished from others on the basis of the type of
switching circuits used.

 First Generation Computers

First generation computers used Thermion valves. These computers were large in size and writing programs
on them was difficult. Some of the computers of this generation were:

ENIAC: It was the first electronic computer built in 1946 at University of Pennsylvania, USA by John
Eckert and John Mauchy. It was named Electronic Numerical Integrator and Calculator (ENIAC). The
ENIAC was 3050 feet long, weighed 30 tons, contained 18,000 vacuum tubes, 70,000 registers, 10,000
capacitors and required 150,000 watts of electricity. Today your favorite computer is many times as
powerful as ENIAC, still size is very small.

EDVAC: It stands for Electronic Discrete Variable Automatic Computer and was developed in 1950. The
concept of storing data and instructions inside the computer was introduced here. This allowed much faster
operation since the computer had rapid access to both data and instructions. The other advantages of storing
instruction was that computer could do logical decision internally.

Other Important Computers of First Generation

EDSAC: It stands for Electronic Delay Storage Automatic Computer and was developed by M.V. Wilkes
at Cambridge University in 1949.

UNIVAC-1: Ecker and Mauchly produced it in 1951 by Universal Accounting Computer setup.

Limitations of First Generation Computer

Followings are the major drawbacks of First generation computers.

 The operating speed was quite slow.

 Power consumption was very high.

 It required large space for installation.

 The programming capability was quite low.

 Second Generation Computers

Around 1955 a device called Transistor replaced the bulky electric tubes in the first generation computer.
Transistors are smaller than electric tubes and have higher operating speed. They have no filament and
require no heating. Manufacturing cost was also very low. Thus the size of the computer got reduced
considerably.
It is in the second generation that the concept of Central Processing Unit (CPU), memory, programming
language and input and output units were developed. The programming languages such as COBOL,
FORTRAN were developed during this period. Some of the computers of the Second Generation were

 IBM 1620: Its size was smaller as compared to First Generation computers and mostly used for
scientific purpose.
 IBM 1401: Its size was small to medium and used for business applications.

 CDC 3600: Its size was large and is used for scientific purposes.

 Third Generation Computers

The third generation computers were introduced in 1964. They used Integrated Circuits (ICs). These ICs
are popularly known as Chips. A single IC has many transistors, registers and capacitors built on a single
thin slice of silicon. So it is quite obvious that the size of the computer got further reduced. Some of the
computers developed during this period were IBM-360, ICL-1900, IBM-370, and VAX-750. Higher level
language such as BASIC (Beginners All purpose Symbolic Instruction Code) was developed during this
period.

Computers of this generation were small in size, low cost, large memory and processing speed is very high.

 Fourth Generation Computers

The present day computers that you see today are the fourth generation computers that started around 1975.
It uses large scale Integrated Circuits (LSIC) built on a single silicon chip called microprocessors. Due to
the development of microprocessor it is possible to place computer’s central processing unit (CPU) on
single chip. These computers are called microcomputers. Later very large scale Integrated Circuits
(VLSIC) replaced LSICs.

Thus the computer which was occupying a very large room in earlier days can now be placed on a table.
The personal computer (PC) that you see in your school is a Fourth Generation Computer.

 Fifth Generation Computer

The computers of 1990s are said to be Fifth Generation computers. The speed is extremely high in fifth
generation computer. Apart from this it can perform parallel processing. The concept of Artificial
intelligence has been introduced to allow the computer to take its own decision. It is still in a
developmental stage.

6. Draw and describe the basic organization of computer system.

Or: Draw and discuss the anatomy of computer.

Ans: Basic computer organizations: A computer as shown in Figure performs basically five major
operations or functions irrespective of their size and make. These are 1) it accepts data or instructions by
way of input, 2) it
stores data, 3) it can
process data as
required by the user, 4)
it gives results in the
form of output, and 5) it controls all operations inside a computer. We discuss below each of these
operations.

Figure 1.5 Basic computer Organizations

Input: This is the process of entering data and programs in to the computer system. You should know that
computer is an electronic machine like any other machine which takes as inputs raw data and performs
some processing giving out processed data. Therefore, the input unit takes data from us to the computer in
an organized manner for processing.

Storage: The process of saving data and instructions permanently is known as storage. Data has to be fed
into the system before the actual processing starts. It is because the processing speed of Central Processing
Unit (CPU) is so fast that the data has to be provided to CPU with the same speed. Therefore the data is
first stored in the storage unit for faster access and processing. This storage unit or the primary storage of
the computer system is designed to do the above functionality. It provides space for storing data and
instructions.

The storage unit performs the following major functions:

 All data and instructions are stored here before and after processing.
 Intermediate results of processing are also stored here.

Processing: The task of performing operations like arithmetic and logical operations is called processing.
The Central Processing Unit (CPU) takes data and instructions from the storage unit and makes all sorts of
calculations based on the instructions given and the type of data provided. It is then sent back to the storage
unit.

Output: This is the process of producing results from the data for getting useful information. Similarly the
output produced by the computer after processing must also be kept somewhere inside the computer before
being given to you in human readable form. Again the output is also stored inside the computer for further
processing.

Control: The manner how instructions are executed and the above operations are performed. Controlling of
all operations like input, processing and output are performed by control unit. It takes care of step by step
processing of all operations in side the computer.

7.Draw the logical diagram of CPU? What are the components of CPU and write their functions.
Ans: The CPU is a silicon chip that contains millions of tiny electrical
components.

The CPU’s three main parts are:

 Control Unit: Coordinates processing steps
 Arithmetic Logic Unit (ALU): Performs calculations and
decisions
 Registers: Small, fast storage areas for instructions and data
 Figure 1.6 CPU
8.What are the classifications of computer?
Ans: Based on capacity and structure computer can be classified as:
 Super Computer
 Mainframe Computer
 Mini Computer
 Micro Computer
Based on signal computer can be classified as:
 Analog Computer
 Digital Computer
 Hybrid Computer

9.Describe the computer classification based on signal.

Ans: Based signal computer can be classified as:

 Analog Computer
 Digital Computer
 Hybrid Computer
Analog Computer: A computer that represents data in terms of physical measures or quantities and
proceeds along a continuum constituted by its components. Analog computers are especially suited for the
solution of complex non-linear equations and for the simulation of multi-dimensional, parallel and
continuous processes. There is no restriction on the physical processes analog computers may utilize.
 An analog computer can work both mechanically and electronically
 Analog computer handles continuous variables
 Analog Computer can carry out multiple tasks simultaneously

For Example: Thermometer

Digital Computer: A computer that stores data in terms of digits (numbers) and proceeds in discrete steps
from one state to the next. The states of a digital computer typically involve binary digits which may take
the form of the presence or absence of magnetic markers in a storage medium ( see memory), on-off
switches or relays. In digital computers, even letters, words and whole texts are represented digitally.

Figure 1.8 Personal Computer (PC)

Hybrid Computer: Hybrid computers are computers that exhibit features of analog computers and digital
computers. The digital component normally serves as the controller and provides logical operations, while
the analog component normally serves as a solver of differential equations.
 Figure 1.9 Polish Hybrid computer WAT 1001

10.What are the classifications of digital computer?

Or: What are the classification of computer based on capacity and structure?
Ans: Based on capacity and structure digital computer can be classified as:
 Super Computer
 Mainframe Computer
 Mini Computer
 Micro Computer

Super Computer: The largest computers are supercomputers. They are the most powerful, the most
expensive, and the fastest. They are capable of processing trillions of instructions per second. Examples of
users of these computers are governmental agencies, such as the IRS, the National Weather Service, and the
National Defense Agency. Also, they are used in the making of movies, space exploration, and the design
of many other machines. The Cray supercomputer is nicknamed "Bubbles", because of its bubbling coolant
liquids. Cray supercomputers, the first of which was invented by Seymour Cray, now maintain 75 percent
of the supercomputer market. Supercomputers are used for tasks that require mammoth data manipulation.
Example: IBM Roadrunner, Cray Jaguar

Mainframe Computer: Large computers are called mainframes. Mainframe computers process data at
very high rates of speed, measured in the millions of instructions per second. They are very expensive,
costing millions of dollars in some cases. Mainframes are designed for multiple users and process vast
amounts of data quickly. Banks, insurance companies, manufacturers, mail-order companies, and airlines
are typical users. Mainframes are often ‘servers’-- computers that control the networks of computers for
large companies like catalog merchandiser L. L. Bean.
Example: IBM 370, IBM 168

Mini Computer: A minicomputer (colloquially, mini) is a class of multi-user computers that lies in the
middle range of the computing spectrum, in between the largest multi-user systems (mainframe computers)
and the smallest single-user systems (microcomputers or personal computers). The class at one time formed
a distinct group with its own hardware and operating systems, but the contemporary term for this class of
system is midrange computer, such as the higher-end SPARC, POWER and Itanium -based systems from
Sun Microsystems, IBM and Hewlett-Packard.
Example: PDP – 11, PDP – 45

Micro Computer: A microcomputer is a computer with a microprocessor as its central processing unit.
They are physically small compared to mainframe and minicomputers. Many microcomputers (when
equipped with a keyboard and screen for input and output) are also personal computers (in the generic
sense)
Example: IBM, DELL, Packard Bell
11. Write the comparison of super, mainframe, mini and micro computer.

Super Mainframe Micro

Compared Item Mini Computer
Computer Computer Computer

Word Length 32-64 16-32 8-16

Memory
8.4 million 256-512 KB 32-64 KB
Capacity

Visual display,
floppy disc,
Peripherals All types All types Wide variety magnetic tape,
dot matrix
printer

FORTRAN,
All levels of All levels of All levels of COBOL,
Languages programmin programming programming BASIC,
g languages languages languages PASCAL, C,
JAVA etc

Software All type All types Wide variety Limited

IBM
Roadrunner IBM 370 PDP – 11 IBM, DELL,
Examples
Cray Jaguar IBM 168 PDP - 45 Packard Bell

12.What are the characteristics of super computer?

 The largest computers are supercomputers
 They are the most powerful, the most expensive, and the fastest
 They are capable of processing trillions of instructions per second
 Vector processing, Liquid cooling, Non-Uniform Memory Access (NUMA), Striped disks
(the first instance of what was later called RAID), Parallel file systems are Technologies
developed for supercomputers

 For example:
o 1983 Cray X-MP/4
o 1938 Zuse Z1
o 2008 IBM Roadrunner
o 2009 Cray Jaguar
13.List uses area of super computer.
Ans: Supercomputers are used for highly calculation-intensive tasks such as :
 Problems involving
 Quantum physics,
 Weather forecasting,
 Climate research,
 Molecular modeling (computing the structures and properties of chemical compounds,
 Biological macromolecules, polymers, and crystals),
 Physical simulations (such as simulation of airplanes in wind tunnels,
 Simulation of the detonation of nuclear weapons, and
 Research into nuclear fusion).
14.What are the characteristics of mainframe computer?

Ans: The characteristics of mainframe computer are:

 Large computers are called mainframes.

 Mainframe computers process data at very high rates of speed, measured in the millions of
instructions per second.

 They are very expensive, costing millions of dollars in some cases.

 Mainframes are designed for multiple users and process vast amounts of data quickly.

 Banks, insurance companies, manufacturers, mail-order companies, and airlines are typical
users.

 Mainframes are often ‘servers’-- computers that control the networks of computers for large
companies like catalog merchandiser L. L. Bean.

 For example:

o 1942 ENIAC

o 1944 MarkI

o 1949 BINAC

o 1960 Whirlwind

o 1952 UNIVAC

o 1953 IBM 701

o 1963 IBM 360

15.What are the characteristics of minicomputer?

Ans: The characteristics of minicomputer are:

 Have limited data channel capacity
 Limited range of peripherals
 Limited software available
 Limited support offered by the manufacturer
 Facility for directs operation of the machine by the end user
 Favorable cost/performance ratio
 Air-conditioning is not necessary and is provided in many cases only for dust control
 For example: IBM's AS/400e

16.What are the characteristics of micro computer?

Ans: The characteristics of micro computer are:

 Computers are built to carry out a small variety of instructions

  It is not necessary to have more than 100 distinct instructions even for a very powerful
computer
 Instructions are extremely simple, e.g add, subtract, read a character, write a character,
compare numbers, characters etc.
 Most instructions are carried out in less than a millionth of a second
 Instructions are carried out obediently with no question asked
 Instructions are carried out without any mistakes
 For example: ALU, Calculator etc

17.What is computer bus? Describe the types of computer buses.

Ans: A bus, in computing, is a set of physical connections (cables, printed circuits, etc.) which can be
shared by multiple hardware components in order to communicate with one another.

The purpose of buses is to reduce the number of "pathways" needed for communication between the
components, by carrying out all communications over a single data channel. This is why the metaphor of a
"data highway" is sometimes used.

Figure 1.10 Computer Bus

Different types of bus are:

 Address bus
 Data bus
 Control bus
Control Bus:
 It is a bidirectional bus, as it also transmits response signals from the hardware.
 The control bus is used by the CPU to direct and monitor the actions of the other
functional areas of the computer.
 It is used to transmit a variety of individual signals (read, write, interrupt,
acknowledge, and so forth) necessary to control and coordinate the operations
of the computer.
 The individual signals transmitted over the control bus and their functions are covered
in the appropriate functional area description.
Address Bus :
 The address bus consists of all the signals necessary to define any of the possible
memory address locations within the computer, or for modular memories any of the
possible memory address locations within a module.
 An address is defined as a label, symbol, or other set of characters used to designate a
location or register where information is stored.
 Before data or instructions can be written into or read from memory by the CPU or I/O
sections, an address must be transmitted to memory over the address bus.
 It is a unidirectional bus.

Data Bus:
 It is a bidirectional bus.
  The bidirectional data bus, sometimes called the memory bus, handles the transfer of all
data and instructions between functional areas of the computer.
 The bidirectional data bus can only transmit in one direction at a time.
 The data bus is used to transfer instructions from memory to the CPU for execution.
 It carries data (operands) to and from the CPU and memory as required by instruction
translation.
 The data bus is also used to transfer data between memory and the I/O section during
input/output operations.

18.What do you mean by computer language?

Ans: Computer Language: The term language is a system of communication between persons. Some of
the basic natural languages that we are familiar with are Bangla, English, Hindi etc. These are the
languages used to communicate among various categories of persons. But how we will communicate with
our computer. Our computer will not understand any of these natural languages for transfer of data and
instruction. So there are programming languages specially developed so that we could pass our data and
instructions to the computer to do specific job. We must have heard names like FORTRAN, BASIC,
COBOL etc. These are programming languages. So instructions or programs are written in a particular
language based on the type of job.
As an example, for scientific application FORTRAN and C languages are used.
On the other hand COBOL is used for business applications.

19.Name different types of computer language.

Ans: Different types of Programming Languages:

There are two major types of programming languages:

 Low Level Languages and

 High Level Languages

Low Level languages are further divided into

o Machine language and
o Assembly language.

20. Describe Low level languages.

Low Level Languages: The term low level means closeness to the way in which the machine has been
built. Low level languages are machine oriented and require extensive knowledge of computer hardware
and its configuration.

Low Level languages are further divided into

o Machine language and
o Assembly language.
Machine Language

Machine Language is the only language that is directly understood by the computer. It does not needs any
translator program. We also call it machine code and it is written as strings of 1's (one) and 0’s (zero).
When this sequence of codes
is fed to the computer, it recognizes the codes and converts it in to electrical signals needed to run it. For
example, a program instruction may look like this:

1011000111101
It is not an easy language for you to learn because of its difficult to understand. It is efficient for the
computer but very inefficient for programmers. It is considered to the first generation language. It is also
difficult to debug the program written in this language.

Advantage: The only advantage is that program of machine language run very fast because no translation
program is required for the CPU.

Disadvantages:

 It is very difficult to program in machine language. The programmer has to know details of
hardware to write program.
 The programmer has to remember a lot of codes to write a program which results in program
errors.
 It is difficult to debug the program.
Assembly Language: It is the first step to improve the programming structure. You should know that
computer can handle numbers and letter. Therefore some combination of letters can be used to substitute
for number of machine codes.

The set of symbols and letters forms the Assembly Language and a translator program is required to
translate the Assembly Language to machine language. This translator program is called `Assembler'. It is
considered to be a second-generation language.

Advantages:

 The symbolic programming of Assembly Language is easier to understand and saves a lot of time
and effort of the programmer.
 It is easier to correct errors and modify program instructions.
 Assembly Language has the same efficiency of execution as the machine level language.
Disadvantages:

 One of the major disadvantages is that assembly language is machine dependent.

 A program written for one computer might not run in other computers with different hardware
configuration.
21.Define High level languages

Ans: High level languages : We know that assembly language and machine level language require deep
knowledge of computer hardware where as in higher language we have to know only the instructions in
English words and logic of the problem irrespective of the type of computer we are using.

Higher level languages are simple languages that use English and mathematical symbols like +, -, %, / etc.
for its program construction.
We should know that any higher level language has to be converted to machine language for the computer
to understand.

Higher level languages are problem-oriented languages because the instructions are suitable for solving a
particular problem.

For example COBOL (Common Business Oriented Language) is mostly suitable for business oriented
language where there is very little processing and huge output.

There are mathematical oriented languages like FORTRAN (Formula Translation) and BASIC (Beginners
All-purpose Symbolic Instruction Code) where very large processing is required.

Thus a problem oriented language designed in such a way that its instruction may be written more like the
language of the problem. For example, businessmen use business term and scientists use scientific terms in
their respective languages.

Advantages of High Level Languages

 Higher level languages have a major advantage over machine and assembly languages that higher
level languages are easy to learn and use. It is because that they are similar to the languages used
by us in our day to day life.

22.What are editor, assembler, compiler and interpreter?

Ans: Editor: Editing is the process of selecting and preparing language, images, sound, video, or film
through processes of correction, condensation, organization, and other modifications in various media. A
medium by which we edit computer languages is called an editor.

Assembler: We know that computer can handle numbers and letter. Therefore some combination of letters
can be used to substitute for number of machine codes. The set of symbols and letters forms the Assembly
Language and a translator program is required to translate the Assembly Language to machine language.
This translator program is called `Assembler'.

Compiler It is a program translator that translates the instruction of a higher level language to machine
language. It is called compiler because it compiles machine language instructions for every program
instructions of higher level language. Thus compiler is a program translator like assembler but more
sophisticated. It scans the entire program first and then translates it into machine code.

The programs written by the programmer in higher level language is called source program. After this
program is converted to machine languages by the compiler it is called object program.
 Higher Level Language

----------------------------------  (Compile)  Program Machine Language Program

A compiler can translate only those source programs, which have been written, in that language for which
the compiler is meant for. For example FORTRAN compiler will not compile source code written in
COBOL language.

Object program generated by compiler is machine dependent. It means programs compiled for one type of
machine will not run in another type. Therefore every type of machine must have its personal compiler for
a particular language. Machine independence is achieved by using one higher level language in different
machines.

Interpreter

An interpreter is another type of program translator used for translating higher level language into machine
language. It takes one statement of higher level languages, translate it into machine language and
immediately execute it. Translation and execution are carried out for each statement. It differs from
compiler, which translate the entire source program into machine code and does involve in its execution.

The advantage of interpreter compared to compiler is its fast response to changes in source program. It
eliminates the need for a separate compilation after changes to each program. Interpreters are easy to write
and do not require large memory in

computer. The disadvantage of interpreter is that it is time consuming method because each time a
statement in a program is executed then it is first translated. Thus compiled machine language program runs
much faster than an interpreted program.

23.Write short notes on real time processing, online processing and timesharing processing?

Ans: Real time processing: In computer science, real-time computing (RTC), or reactive computing, is the
study of hardware and software systems that are subject to a "real-time constraint"—i.e., operational
deadlines from event to system response. By contrast, a non-real-time system is one for which there is no
deadline, even if fast response or high performance is desired or preferred. The needs of real-time software
are often addressed in the context of real-time operating systems, and synchronous programming
languages, which provide frameworks on which to build real-time application software.

Online processing: Term used to refer to equipment that operates under control of the central processing
unit (CPU). On-line processing equipment can be placed in the same location as the CPU or in a remote
location. Generally, on-line processing refers to processing using a terminal (input) that is remote from the
CPU.
Timesharing processing: This involves the CPU allocating individual slices of time to a number of users
on the computer system. As the number of users increases the response time for each terminal declines. The
speed of the CPU compared to that of the VDU and terminal is so much faster that it gives the user the
impression that they are the sole user of the system.

24.Explain system utilities.

Ans: System Utilities: A single piece of utility software is usually called a utility or tool. Various utilities
are used to build a system are called system utilities.
Utility software is a kind of system software designed to help analyze, configure, optimize and maintain the
computer

Utility software categories are as:

 Disk storage utilities

 Disk defragmenters utilities

 Disk checkers utilities

 Disk cleaners utilities

 Disk space analyzers utilities

 Backup utilities

 Disk compression utilities

 File managers utilities

 Archive utilities

 System profilers utilities

 Anti-virus utilities

 Hex editors utilities

 Data compression utilities

 Cryptographic utilities

 Launcher applications utilities

 Registry cleaners utilities

 Network utilities

 Command line interface (CLI) utilities

 Graphical user interface (GUI utilities

 Chapter 2
Computer Hardware
1.What is computer hardware? Describe the classification of computer hardware?
Or: What is input hardware? Give example.
Or: What is output hardware? Give example.

Ans: Computer Hardware: Hardware (computer) components, equipments involved in the function of a
computer. Computer hardware consists of the components that can be physically handled.

Computer hardware can be classified into three main categories:

 Input
 Output

 Storage

Input Devices/ hardware: Input devices consist of external devices - that is, devices outside of the
computer's CPU - that provide information and instructions to the computer.
Example:

 Keyboard.
 Touch screen

 Light pen

 Mouse

 Joystick

 Optical Scanner

 Microphone

 Voice recognition

 Modem

Output Devices/ hardware: Output hardware consists of external devices that transfer information from
the computer's CPU to the computer user. A video display, or screen, convert’s information generated by
the computer into visual information.
Example:

 Display
 CRT
  Flat Panel or LCD

 Printers

 Speakers

Storage Devices/ hardware: Storage hardware provides permanent storage of information and programs
for retrieval by the computer. The two main types of storage devices are disk drives and memory.

There are several types of disk drives: hard, floppy, magneto-optical, and compact.

2.Write short notes on Keyboard.

Ans: Keyboard: A keyboard is a typewriter- like device that allows
the user to type in text and commands to the computer. Some
keyboards have special function keys or integrated pointing
devices, such as a trackball or touch-sensitive regions that let the
user's finger motions move an on-screen cursor.

Figure 2.1 Keyboard

3.Write short notes on Touch Screen. How Touch Screen works?

Ans: Touch Screen : A Touch Screen is a display which can detect the location of touches within the
display area. This allows the display to be used as an input device,
removing the keyboard and/or the mouse as the primary input device
for interacting with the display's content. Such displays can be
attached to computers or, as terminals, to networks. Touch Screens also
have assisted in recent changes in the design of personal digital
assistant (PDA), satellite navigation and mobile phone devices, making
these devices more usable.
Figure
2.2 Touch Screen

4.Write short notes on light pen. How touch light pen works?

Ans: Light pen: An input device that utilizes a light-sensitive detector to select objects on a display screen.
A light pen is similar to a mouse, except that with a light pen you can move the pointer and select objects
on the display screen by directly pointing to the objects with the pen.

A light pen is a stylus with a light sensitive tip that is used to draw
directly on a computer's video screen or to select information on the
screen by pressing a clip in the light pen or by pressing the light pen
against the surface of the screen. The pen contains light sensors that
identify which portion of the screen it is passed over.
Figure 2.3 Light
pen

5.Write short notes on mouse. How mouse works? What are the types of mouse?

Ans: Mouse: A mouse is a pointing device designed to be gripped by one hand. It has a detection device
(usually a ball) on the bottom that enables the user to control the motion of an on-screen pointer, or cursor,
by moving the mouse on a flat surface. As the device moves across the surface, the cursor moves across the
screen. To select items or choose commands on the screen, the user presses a button on the mouse.
There are two types of Mouse:

Figure 2.4 Mouse

Wheel Cordless
• Mouse Mouse within a text document; connects to
Wheel mouse – Contains a rotating wheel used to scroll vertically
PS/2 port or USB port
• Cordless mouse – Uses infrared signals to connect to the computer’s IrDA port; it must be within
sight of the receiving port

6.Explain Graphics tablets.

Ans: A graphics tablet (or digitizing tablet, graphics pad, drawing tablet is a computer input device that
allows one to hand-draw images and graphics, similar to the way one draws images with a pencil and
paper.

Figure 2.5 Graphics tablets

These tablets may also be used to capture data or handwritten signatures. It can also be

used to trace an image from a piece of paper which is taped or otherwise secured to the surface. Capturing
data in this way, either by tracing or entering the corners of linear poly-lines or shapes is called digitizing.
A graphics tablet (also called pen pad or digitizer) consists of a flat surface upon which the user may
"draw" or trace an image using an attached stylus, a pen-like drawing apparatus. The image generally does
not appear on the tablet itself but, rather, is displayed on the computer monitor. Some tablets however,
come as a functioning secondary computer screen that you can interact with directly using the stylus.

7.What is joystick? What are the types of joysticks? How joysticks work?
Ans: Joystick: A joystick is a pointing device composed of a lever that moves in multiple directions to
navigate a cursor or other graphical object on a computer screen.

A joystick is an input device consisting of a stick that pivots on a

base and reports its angle or direction to the device it is controlling.
Joysticks are often used to control video games, and usually
have one or more push-buttons whose state can also be read by the
computer. A popular variation of the joystick used on modern video
game consoles is the analog stick. Figure 2.6
Joystick

The joystick has been the principal flight control in the cockpit of many aircraft, particularly military fast
jets, where center stick or side-stick location may be employed.
Application: The main use of a joystick is to play computer games by controlling the way that something
moves on the screen.
8.What is barcode? How barcode works?

Ans: Barcode: A barcode is an optical machine-readable representation of data, which shows certain data
on certain products. Originally, barcodes represented data in the widths (lines) and the spacings of parallel
lines, and may be referred to as linear or 1D (1 dimensional) barcodes or symbologies. They also come in
patterns of squares, dots, hexagons and other geometric patterns within images termed 2D (2 dimensional)
matrix codes or symbologies. Although 2D systems use symbols other than bars, they are generally referred
to as barcodes as well. Barcodes can be read by optical scanners called barcode readers, or scanned from an
image by special software.

• A bar code is a set of lines of different thicknesses that represent a number

• Bar Code Readers are used to input data from bar codes. Most products in shops have bar codes on
them
• Bar code readers work by shining a beam of light on the lines that make up the bar code and
detecting the amount of light that is reflected back

9.Explain OCR system.

Ans : OCR system : Optical character recognition, usually abbreviated to OCR, is the mechanical or
electronic translation of scanned images of handwritten, typewritten or printed text into machine-encoded
text. It is widely used to convert books and documents into electronic files, to computerize a record-
keeping system in an office, or to publish the text on a website. OCR makes it possible to edit the text,
search for a word or phrase, store it more compactly, display or print a copy free of scanning artifacts, and
apply techniques such as machine translation, text-to-speech and text mining to it. OCR is a field of
research in pattern recognition, artificial intelligence and computer vision.

10.What is scanner? What are the types of scanners? How scanner works?

A scanner can be used to input pictures and text into a computer. There are two main types of scanner;
Hand-held and Flat-bed.

Figure 2.7 Scanner

The scanner can be categorized as follows:

• Handheld scanner: With a handle and typically a trigger button for switching on the light source.

• Flatbed scanner :A flatbed scanner is usually composed of a glass pane (or platen), under which
there is a bright light (often xenon or cold cathode fluorescent) which illuminates the pane, and a
moving optical array in CCD scanning.

• Pen scanner (or wand scanner): A pen-shaped scanner that is swiped.

 • Stationary scanner: Wall- or table-mounted scanners that the barcode is passed under or beside.
These are commonly found at the checkout counters of supermarkets and other retailers.

• Fixed position scanner: An industrial barcode reader used to identify products during manufacture
or logistics. Most often used on conveyor tracks to identify cartons or pallets which need to be
routed to another process or shipping location.

• PDA scanner: A PDA with a built-in barcode reader or attached barcode scanner e.g. Grabba.

• Automatic reader : A back office equipment to read bar coded documents at high speed
(50,000/hour) e.g. Multi scan MT31

11.Explain Mark Sense Reader.

Ans: Mark Sense Reader: A device that reads data from special cards containing conductive or magnetic
marks is called mark sense reader. A mark sense reader is disclosed that views each document individually
to ascertain how each individual person has marked the document in regard to the density of each mark and
then sets a reading threshold for that person. Each mark is scanned, divided into individual cells and a mark
quality is determined. Erasures and smudges are differentiated from intended marks.

12.Explain MICR.

Ans: MICR: The characters are first magnetized in the plane of the paper with a North pole on the right of
each MICR character.
Then they are usually read with a MICR read head which is a device similar in nature to the playback head
in an audio tape recorder, and the letterforms' bulbous shapes ensure that each letter produces a unique
waveform for the character recognition system to provide a reliable character result.
The error rate for the magnetic scanning of the numbers at the bottom of a typical check is smaller than
with optical character recognition systems. For well printed MICR, the can't read rate is usually less than
1% while the substitution rate (misread rate) is in the order of 1 per 100,000 characters.
In 1960s, the MICR fonts became a symbol of modernity, leading to the creation of lookalike "computer"
typefaces that imitated the appearance of the MICR fonts, but, unlike real MICR fonts, had a full character
repertoire.

13.Explain Digital Camera.

Ans: Digital Camera: A digital camera can store many more pictures than an
ordinary camera. Pictures taken using a digital camera are stored inside its
memory and can be transferred to a computer by connecting the camera
to it. A digital camera takes pictures by converting the light passing through
the lens at
the front into a digital image. Figure 2.8
Digital Camera

14.Explain speech input method.

Ans: Speech Input Method: Speech recognition is a type of input in which the computer recognizes words
spoken into a microphone.
 Special software and a microphone are required.
  Latest technology uses continuous speech recognition where the user does not have to pause between
words.
 A speech recognition program can process the input and convert it into machine-recognized
commands or
input
15.Define monitor. Discuss the types of monitor.
Ans: A monitor or display (sometimes called a visual display unit) is an electronic visual display for
computers. The monitor comprises the display device, circuitry, and an enclosure. The display device in
modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD), while older monitors
use a cathode ray tube (CRT).

There are three types of monitor:

 CRT
 LCD
 Plasma

CRT
 High dynamic range (up to around 15,000:1 ,) excellent color, wide gamut and low black level.
 Can display natively in almost any resolution and refresh rate
 No input lag
 Sub-millisecond response times
 Near zero color, saturation, contrast or brightness distortion. Excellent viewing angle.
 Usually much cheaper than LCD or Plasma screens.
 Large size and weight, especially for bigger screens (a 20-inch unit weighs about 50 lb (23 kg))
 High power consumption
 Geometric distortion caused by variable beam travel distances
 Older CRTs are prone to screen burn-in
 Produces noticeable flicker at low refresh rates
LCD
 Very compact and light
 Low power consumption
 No geometric distortion
 Rugged
 Little or no flicker depending on backlight technology
 Limited viewing angle, causing color, saturation, contrast and brightness to vary, even within the
intended viewing angle, by variations in posture.
 Bleeding and uneven backlighting in some monitors, causing brightness distortion, especially
toward the edges.
 Slow response times, which cause smearing and ghosting artifacts. Modern LCDs have response
times of 8 ms or less.
 Only one native resolution. Displaying resolutions either requires a video scaler, lowering
perceptual quality, or display at 1:1 pixel mapping, in which images will be physically too large or
won't fill the whole screen.
 Fixed bit depth, many cheaper LCDs are incapable of truecolor.
 Input lag
 Dead pixels may occur either during manufacturing or through use.
Plasma
 Compact and light.
 High contrast ratios (10,000:1 or greater,) excellent color, wide gamut and low black level.
 High speed response.
 Near zero color, saturation, contrast or brightness distortion. Excellent viewing angle.
 No geometric distortion.
 Highly scalable, with less weight gain per increase in size (from less than 30 in (760 mm) wide to
the world's largest at 150 in (3,800 mm)).
 Large pixel pitch, meaning either low resolution or a large screen.
  Noticeable flicker when viewed at close range
 High operating temperature and power consumption
 Only has one native resolution. Displaying other resolutions requires a video scaler, which
degrades image quality at lower resolutions.
 Fixed bit depth
 Input lag
 Older PDPs are prone to burn-in
 Dead pixels are possible during manufacturing

16.What is sound system. Give example.

Ans: A sound system is a group of DJs (disc jockey) and engineers contributing and working together as
one, playing and producing music.

17.Define printer. Discuss the types of printers.

Ans: Printer: In computing, a printer is a peripheral which produces a hard copy (permanent readable text
and/or graphics) of documents stored in electronic form, usually on physical print media such as paper or
transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or,
in most newer printers, a USB cable to a computer which serves as a document source.

The main categories are: - laser printers, ink-jets, dot-matrix, multifunctional, etc. Normally home computer
users will use ink-jets as they are relatively cheap but superior in quality to dot-matrix. Laser jets and other
printers created by new technology are more expensive and more commonly found in the offices.

Ink-jets(bubble-jets) printers spray ionized tiny drops of ink onto a page to create an image. This is
achieved by using magnetized plates which direct the ink's path onto the paper in the desired pattern.
Almost all ink-jets offer a color option as standard, in varying degrees of resolution. Ink-jet printers are
capable of producing high quality print which almost matches the quality of a laser printer. A standard ink-
jet printer has a resolution of 300 dots per inch, although newer models have improved on that. As a rule
color link-jet printers can also be used as a regular black and white printer.
Laser printers operate by shining a laser beam to produce an image on a drum. The drum is then rolled
through a pool, or reservoir, or toner, and the electrically charged portions of the drum pick up ink. Finally,
using a combination of heat and pressure, the ink on the drum is transferred onto the page. Laser printers
print very fast, and the supply cartridges work a long time. Color laser printers use the same toner-based
printing process as black and white ( B/W) laser printers, except that they combine four different toner
colors. Color laser printers can also be used as a regular black and white laser printer.

LED/LCD printers are types of electro photographic printers that are identical to laser printers in most
ways. Both LCD (liquid crystal display) and LED (light-emitting diode) printers use a light source instead
of a laser to create an image on a drum. In most contexts, "laser printer" covers LCD and LED printers as
well. The print process is almost identical, but LED printers use Light Emitting Diodes to charge the drum,
and the other uses Liquid Crystals. These printers produce a very high quality text and graphics print out.

Impact (Dot-matrix) printers use a set of closely spaced pins and a ribbon to print letters or other
characters on a page. These printers actually impact the page to print a character, much like a typewriter.
Dot-matrix printers vary in terms of speed and the number of pins they have. They can run at a speed
anywhere between 50 and 500 CPS (Characters Per Second). The number of pins, which can vary between
9 to 24, determines the quality of the print job. Dot matrix printers are commonly used for printing
invoices, purchase orders, shipping forms, labels, and other multi-part forms. Dot matrix printers can print
through multi-part forms in a single pass, allowing them to produce more pages than even high-speed laser
printers.

Solid Ink printers are page printers that use solid wax ink sticks in a "phase-change" process. They work
by liquefying wax ink sticks into reservoirs, and then squirting the ink onto a transfer drum, from where it
is cold-fused onto the paper in a single pass. Solid-ink printers offer better color consistency than do most
technologies, with little variation caused by changes in temperature, humidity, or type of paper. Solid ink
machines have better reliability, because they have fewer components in comparison, for example with
color laser printers .

Portable printers are usually fairly lightweight and sometimes carry the option of using a battery instead
of drawing power from the computer. Usually they realize basic print resolutions suitable for plain text
printing. You can find on the market the following types of the portable printers: Thermal printer, Thermal
transfer printer and Ink-Jet printer. The main advantage of thermal and thermal transfer printers is that they
can be very small. The smallest thermal and thermal transfer printers weigh approximately one pound.
Usually the ink-jet portable printer weighs more than 2 pounds. Thermal printers require a special type of
paper.

Plotters are large-scale printers that are very accurate at reproducing line drawings. They are commonly
used for technical drawings such as engineering drawings or architectural blueprints. The two basic types
of plotters are called flatbed plotters and drum plotters. Flatbed plotters are horizontally aligned with a flat
surface to which a piece of paper is attached. The paper remains stationary and the printer moves pens
across the paper to draw the image. Drum plotters, also called upright plotters, are vertically positioned.
They have a drum that the paper rolls on. Drum plotters usually make more noise and are more compact
than flatbed plotters.

Digital Photo printers Many middle range printers are now able to print photo quality images. Usually an
option with color printers, specialist photo print heads allow a greater resolution to be achieved to improve
photo image quality. Photo ink jet printers expand their gamuts by adding additional ink colors, usually
light cyan and light magenta.

Network printer is a printer that provides output capabilities to all network users.
Multifunction printers: combine top-quality color ink-jet or laser printing with plain-paper and PC faxing,
color copying and color scanning , telephoning- all in one convenient, space-saving machine. If you work
from home or have a small office a multifunctional device may be ideal.

The Bravo AutoPrinter is the worlds first automated CD/DVD printing system that can truly be called
innovative. It combines automatic, robotic-based CD or DVD printing along with full-color, 2400 dpi disc
printing all in one compact, desktop unit.

Printers for banking: these printers realize innovative technology and functionality to increase
productivity, and reduce costs.

EZ CD/DVD Printers: provide a low cost way to create professional printed CD-Rs and DVD-Rs. Instead
of writing on the CD or applying labels, you can print directly on the CD surface! With high speed
capabilities, a full color image can be printed directly on the top surface of your CDs in less than 1 minute.

Label Printers are the smartest way to print labels one at a time. The printers allow easy installation.
You can get high-quality, professional results every time.

3D Printers ( Z corporation). The ZPrinter 310 System creates physical models directly from computer-
aided design system (“CAD”) and other digital data in hours instead of days. The printer is fast, versatile
and simple, allowing engineers to produce a range of concept models and functional test parts quickly and
inexpensively. The system is ideal for an office environment or educational institution, providing product
developers easy access to a 3D Printer.

18.What are the differences between CISC and RISC

CISC RISC

Pronounced sisk, and stands for Complex Pronounced risk, and stands for Reduced
Instruction Set Computer Instruction Set Computer

Typically CISC chips have a large amount of RISC is that - in theory - because of the more
different and complex instructions. simple instructions

Not easier to design and costly to produce easier to design and cheaper to produce.

CISC chips require more than transistors, RISC chips require fewer transistors,

CISC chips are relatively slow (compared to RISC RISC chips are relatively fast per instruction i.e
chips) per instruction, but use little (less than RISC) use more instruction
instructions.

Chapter 3
Computer Software
1.What is software? What are the types of software?

Or: List the classification of computer software.

Ans: Software: A computer cannot do anything of its own. It must be instructed to do a desired job.

The term “software” refers to the set of computer programs, procedures, and associated documents, which
describes the programs, and how they are to be used.

Software is often divided into two categories:

 Systems Software : Includes the operating system and all the utilities that enable the computer to
function.

 Applications Software : Includes programs that do real work for users. For example, word processors,
spreadsheets, and database management systems fall under the category of applications software.

2.What is system software? List various kinds of system software.

Ans: System software: System software is computer software designed to operate the computer hardware
and to provide and maintain a platform for running application software.

Example:

 Microsoft Windows
 Linux

 Unix

 Mac OSX

 DOS

 BIOS Software

 HD Sector Boot Software

 Device Driver Software i.e Graphics Driver etc

 Linker Software

 Assembler and Compiler Software

Various kinds of system software include:

 Loaders
 Linkers

 Utility software
  Desktop environment / Graphical user interface

 Shells

 BIOS

 Hypervisors

 Boot loaders

3.What is application package? What are the advantages of application packages?

Ans: Application package/software, also known as software application, is computer software

designed to help the user to perform singular or multiple related specific tasks. Typical examples are word
processors, spreadsheets, media players and database applications.

Application software should be contrasted with system software (infrastructure) or middleware (computer
services/ processes integrators), which is involved in integrating a computer's various capabilities, but
typically does not directly apply them in the performance of tasks that benefit the user.

Examples :
1) Opera (Web Browser)
2) Microsoft Word (Word Processing)
3) Microsoft Excel (Spreadsheet software)
5) MySQL (Database Software)
6) Microsoft Powerpoint (Presentation Software)
7) iTunes (Music / Sound Software)
8) VLC Media Player (Audio / Video Software )
9) World of Warcraft (Game Software)
10) Adobe Photoshop (Graphics Software)

Advantages of Application packages:

A. Modularity
- Encapsulate related constructs.

B. Easier Application Design

- Code and compile specification and body separately.

C. Hiding Information
- Only the declarations in the package specification are visible and accessible to application.
- Private constructs in the package body are hidden and inaccessible.
- All coding is hidden in the package body.

D. Added Functionality
- Persistency of variables and coursors.

E. Better Performance
- The entire package is loaded into memory when the
package is first referenced.
- There is only one copy in memory for all users.
- The dependency hierarchy is simplified.
F. Overloading
- Multiple subprograms of the same name.
4.Define Firmware and human ware.

Ans: Firmware: With the advancement in technology and the reduction in hardware cost, today software is
also being made available by many manufacturers on ROM chips. Such programs(software) which are
made available on hardware are known as firmware. Firmware often refers to a sequence of instructions
which is substituted for hardware.

In precise, firmware is software substituted for hardware, and stored in ROM.

Humanware: Humanware refers to the persons who design, program, and operate a computer. There are
numerous categories of jobs, but the threse principal positions for a large computer installations are: system
analyst, programmer, and computer operator. People in each of these areas generally perform special-
purpose tasks under the supervision of a director or manager.

5.Mention the differences between hardware and software.

Hardware Software

Hardware refers to the physical Software refers to things that are used
components of the computer that by the hardware.
run the software.
Hardware includes every Software is what makes the hardware
computer-related object that you function properly and to an optimum
can physically touch and handle. level.

Hardware is a physical device Software is code and instructions that

something that you're able to tell a computer and/or hardware how
touch and see to operate.

Hard drive, the motherboard, the Programs that you install on your
video and sound cards, the computer including games, word
monitor, the printer, the keyboard processing programs, spreadsheet
and the mouse. programs, graphic design programs.

Chapter 4
Operating System
1.What is operating system?
Ans: Operating system: An operating system is an integrated collection of programs which takes control
all over the operation of computer system without human intervention.

Example:

 Windows
 Linux

 Unix

 MacOS

2.What are the classifications of operating system?

Ans: Operating systems can be classified as follows:

 Multi-user : Allows two or more users to run programs at the same time. Some operating
systems permit hundreds or even thousands of concurrent users.
 Multiprocessing : Supports running a program on more than one CPU.
 Multitasking : Allows more than one program to run concurrently.
 Multithreading : Allows different parts of a single program to run concurrently.
 Real time: Responds to input instantly. General-purpose operating systems, such as DOS
and UNIX, are not real-time.

3.Why operating system is necessary for computer?

Ans: Operating system necessity: In computing, an operating system (OS) is software (programs and
data) that provides an interface between the hardware and other software. The OS is responsible for
management and coordination of

processes and allocation and sharing of hardware resources such as RAM and disk space,
and acts as a host for computing applications running on the OS. An operating system may
also provide orderly accesses to the hardware by completing software routines. This
relieves the application programmers from having to manage these details.

4.What are the characteristics of operating system?

Ans: Main Characteristics of operating system are:

 Management of the processor

 Management of the random access memory:

 Management of input/output

 Management of execution of applications

 Management of authorizations

 File management
  Information management

Chapter 5
Storage devices
1.What is storage device? Give examples.
Or: What are the types of storage device?

Ans: Storage device: A storage device is a hardware device designed to store information. There are two
types of storage devices used in computers; a 'primary storage' device and a 'secondary storage' device.
There are two types of storage device:
 Primary Storage device: A storage location that holds memory for short periods of times. For
example, computer RAM is an example of a primary storage device.
 Secondary Storage device: A storage medium that holds information until it is deleted or
overwritten. For example, a floppy disk drive or a hard disk drive is an example of a secondary
storage device.

2.What are the characteristics of a good storage device?

Ans: The characteristics of a good storage device are:
 Volatility
o Non-volatile memory
o Volatile memory
 Differentiation
o Dynamic random access memory
o Static memory
 Mutability
o Read/write storage or mutable storage
o Read only storage
o Slow write, fast read storage
 Accessibility
o Random access
o Sequential access
 Addressability
o Location-addressable
o File addressable
o Content-addressable
 Capacity
o Raw capacity
o Memory storage density
 Performance
o Latency
o Throughput
 Environmental Impact
 o Energy
o Recycling
o Manufacturing

3.What are the main classifications of computer memories?

Ans: Memory is the main component of a computer system. It stores instructions and data in binary form
that is used by the central processing unit.

Memories can be classified into two types such as

1) Primary memory
 ROM memory
 PROM
 EPROM
 EEPROM
 RAM memory
 SRAM
 DRAM
2) Secondary memory
 Magnetic tape,
 Magnetic disc
 Floppy disc
 Hard disc
 Optical disc
 CD-ROM
 WORM

4.What are ROM, PROM, EPROM, EEPROM, RAM, DRAM, SRAM, SDRAM, Flash memory,
MRAM?
Or Write the comparisons of various types of semiconductor memory.

Ans: Read Only Memory (ROM): There is another memory in computer, which is called Read Only
Memory (ROM). Again it is the ICs inside the PC that form the ROM. The storage of program and data in
the ROM is permanent. The ROM stores some standard processing programs supplied by the manufacturers
to operate the personal computer. The ROM can only be read by the CPU but it cannot be changed. The
basic input/output program is stored in the ROM that examines and initializes various equipment attached
to the PC when the switch is made ON. The memories, which do not loose their content on failure of power
supply, are known as non-volatile memories. ROM is non-volatile memory.
PROM: There is another type of primary memory in computer, which is called Programmable Read Only
Memory (PROM). You know that it is not possible to modify or erase programs stored in ROM, but it is
possible for you to store your program in PROM chip. Once the programmes are written it cannot be
changed and remain intact even if power is switched off. Therefore programs or instructions written in
PROM or ROM cannot be erased or changed.
EPROM: This stands for Erasable Programmable Read Only Memory, which over come the problem of
PROM & ROM. EPROM chip can be programmed time and again by erasing the information stored earlier
in it. Information stored in EPROM exposing the chip for some time ultraviolet light and it erases chip is
reprogrammed using a special programming facility. When the EPROM is in use information can only be
read.

EEPROM : EEPROM (also written E2PROM and pronounced "e-e-prom," "double-e prom" or simply
"e-squared") stands for Electrically Erasable Programmable Read-Only Memory and is a type of non-
volatile memory used in computers and other electronic devices to store small amounts of data that must be
saved when power is removed, e.g., calibration tables or device configuration.

When larger amounts of static data are to be stored (such as in USB flash drives) a specific type of
EEPROM such as flash memory is more economical than traditional EEPROM devices. EEPROMs are
realized as arrays of floating-gate transistors.

Flash memory Flash memory may be considered as a development of EEPROM technology. Data can
be written to it and it can be erased, although only in blocks, but data can be read on an individual cell
basis. To erase and re-

programme areas of the chip, programming voltages at levels that are available within electronic equipment
are used. It is also non-volatile, and this makes it particularly useful. As a result Flash memory is widely
used in many applications including memory cards for digital cameras, mobile phones, computer memory
sticks and many other applications. It is Hybrid of RAM/ROM

RAM: Random-access memory (RAM) is a form of computer data storage. Today, it takes the form of
integrated circuits that allow stored data to be accessed in any order (i.e., at random). "Random" refers to
the idea that any piece of data can be returned in a constant time, regardless of its physical location and
whether or not it is related to the previous piece of data.[1]

DRAM Dynamic RAM is a form of random access memory. DRAM uses a capacitor to store each bit of
data, and the level of charge on each capacitor determines whether that bit is a logical 1 or 0. However
these capacitors do not hold their charge indefinitely, and therefore the data needs to be refreshed
periodically. As a result of this dynamic refreshing it gains its name of being a dynamic RAM. DRAM is
the form of semiconductor memory that is often used in equipment including personal computers and
workstations where it forms the main RAM for the computer.
SRAM Static Random Access Memory. This form of semiconductor memory gains its name from the
fact that, unlike DRAM, the data does not need to be refreshed dynamically. It is able to support faster read
and write times than DRAM (typically 10 ns against 60 ns for DRAM), and in addition its cycle time is
much shorter because it does not need to pause between accesses. However it consumes more power, is less
dense and more expensive than DRAM. As a result of this it is normally used for caches, while DRAM is
used as the main semiconductor memory technology.
SDRAM Synchronous DRAM. This form of semiconductor memory can run at faster speeds
than conventional DRAM. It is synchronized to the clock of the processor and is capable of
keeping two sets of memory addresses open simultaneously. By transferring data alternately from
one set of addresses, and then the other, SDRAM cuts down on the delays associated with non-
synchronous RAM, which must close one address bank before opening the next.
MRAM This is Magneto-resistive RAM, or Magnetic RAM. It is a non-volatile RAM memory
technology that uses magnetic charges to store data instead of electric charges. Unlike
technologies including DRAM, which require a constant flow of electricity to maintain the
integrity of the data, MRAM retains data even when the power is removed. An additional
advantage is that it only requires low power for active operation. As a
result this technology could become a major player in the electronics industry now that
production processes have been developed to enable it to be produced.

5.What is memory? Why memory is needed in computer?

Ans: Memory: Computer data storage, often called storage or memory, refers to computer components,
devices, and recording media that retain digital data used for computing for some interval of time.
Computer data storage provides one of the core functions of the modern computer, that of information
retention. It is one of the fundamental components of all modern computers, and coupled with a central
processing unit (CPU, a processor), implements the basic computer model used since the 1940s.
In computing system most important function is storing information. To store information memory is
needed. Without memory it is possible to store information. So memory is essential in computer.

6.What is main memory?

Ans: Main memory: The main memory of the computer is also known as RAM, standing for Random
Access Memory. It is constructed from integrated circuits and needs to have electrical power in order to
maintain its information. When power is lost, the information is lost too! It can be directly accessed by the
CPU. The access time to read or write any particular byte are independent of whereabouts in the memory
that byte is, and currently is approximately 50 nanoseconds (a thousand millionth of a second). This is
broadly comparable with the speed at which the CPU will need to access data. Main memory is expensive
compared to external memory so it has limited capacity. The capacity available for a given price is
increasing all the time. For example many home Personal Computers now have a capacity of 16 megabytes
(million bytes), while 64 megabytes is commonplace on commercial workstations. The CPU will normally
transfer data to and from the main memory in groups of two, four or eight bytes, even if the operation it is
undertaking only requires a single byte.
7.What is secondary memory?
Ans: Secondary memory: Secondary memory is where programs and data are kept on a long-term basis.
Secondary memory is not directly accessible to the CPU. Input/output channels are used to access this non
volatile memory. This memory does not lose the data when the system is powered off. The most familiar
form of secondary memory that is widely used is Hard Disk. Some examples of secondary memory are
USB sticks, floppy drives and Zip drives.

8.What are the differences between Primary memory and Secondary memory?

Primary memory Secondary memory

Primary memory is faster Secondary memory slower than

primary memory
Primary memory is expensive Secondary memory is Cheaper than
primary memory
Connects directly to the processor Not connected directly to the
processor

Low capacity Large capacity

9.Explain memory access, volatile and nonvolatile memory?

Ans; Memory access: When memory is read or written, this is called a memory access. A specific
procedure is used to control each access to memory, which consists of having the memory controller
generate the correct signals to specify which memory location needs to be accessed, and then having the
data show up on the data bus to be read by the processor or whatever other device requested it.
Volatile Memory: Volatile memory is memory that loses its contents when the computer or hardware
device loses power. Computer RAM is a good example of a volatile memory.
Non volatile memory: Non-volatile memory, sometimes abbreviated as NVRAM, is memory that keeps its
contents even if the power is lost. CMOS is a good example of a non-volatile memory.

10.What are the differences between RAM and ROM?

RAM ROM

RAM is an acronym for Random ROM is an acronym for Read Only

Access Memory Memory

This is memory that has data

This is reusable memory that the
permanently written on it and is
computer uses to run programs.
usually not reusable.

PROM (Programmable Read-Only

DDR (Double Data Rate), DDR2 and
Memory) and CD-ROM are just two
SDRAM are all types of RAM.
of the many types of ROM.

ROM, or read only memory, is

RAM is faster than ROM
generally slower than RAM.

Temporary or volatile memory Permanent or non-volatile memory

User can read or write into it. User can only read from it.

11.What are static RAM and Dynamic RAM?

SRAM DRAM

SRAM is an acronym for Static DRAM is an acronym for Dynamic

Random Access Memory Random Access Memory

High speed RAM Relatively slower

SRAM is costly Relatively low cost

Does not require refreshing Requires refreshing periodically

Generally used for cache Used for main memory

Control complexity is less Relatively high Control complexity

12.What are magnetic core storage and semiconductor storage?

Ans: Magnetic core memory is an early form of random access computer memory. It uses small magnetic
rings, the cores, through which wires are threaded to store information via the polarity of the magnetic field
they contain. Such memory is often just called core memory, or, informally, core.

Semiconductor memory uses semiconductor-based integrated circuits to store information. A

semiconductor memory chip may contain millions of tiny transistors or capacitors. Both volatile and non-
volatile forms of semiconductor memory exist. In modern computers, primary storage almost exclusively
consists
of dynamic volatile semiconductor memory or dynamic random access memory. Since the turn of the
century, a type of non-volatile semiconductor memory known as flash memory has steadily gained share as
off-line storage for home computers. Non-volatile semiconductor memory is also used for secondary
storage in various advanced electronic devices and specialized computers.

13.What is floppy disk?

Ans: Floppy Disc: A floppy disk is a data storage medium that is composed of a disk of thin, flexible
("floppy") magnetic storage medium encased in a square or rectangular plastic shell.

Floppy disks are read and written by a floppy disk drive or FDD, the initials of which should not be
confused with "fixed disk drive", which is another term for a (nonremovable) type of hard disk drive.
Invented by the American information technology company IBM, floppy disks in 8-inch (203 mm), 51⁄4 in
(133 mm), and 31⁄2 in (89 mm) formats enjoyed nearly three decades as a popular and ubiquitous form of
data storage and exchange, from the mid-1970s to the late 1990s. While floppy disk drives still have some
limited uses, especially with legacy industrial computer equipment, they have now been largely superseded
by USB flash drives, external hard disk drives, CDs, DVDs, and memory cards.

14.What is the process of formatting a floppy disk?

Ans: The process of formatting a floppy disk:
 Begin by placing the floppy disk that you want to copy into your floppy drive.
 Double click on the My Computer icon on your Desktop until it opens.
 Then gently click on the 3½ Floppy (A:) icon just until it becomes highlighted.
 Then click on the word File, which is contained in your top tool bar area.
 This will pull down a menu for you to now click on the word Format.
 By default, Windows XP will perform a Full Format upon your floppy disk.
 If you want to perform a Quick format, then place a check mark next to the Quick Format option.
 You can also label your Floppy by typing a name into the Volume label white area.

After making your selections, click on the Start button to initiate the format process.

 Windows will warn that Formatting will erase all data on your disk, click the OK button to
continue.
 A progress indicator bar will travel across the screen for depicting the Format progress.
 Windows will notify you when the Format is complete. Click on the OK button to close this
window.
 Then close all open windows to return back to your Windows session.

15.What are the advantages and disadvantages of a floppy disk?

Ans: Advantages of floppy disks:

  Floppy disk is portable and inexpensive.

 Data on a floppy disk can be accessed randomly.

 Data on a floppy disk can be write-protected from being changed accidentally.

 Floppy disk can be used to transfer data from one computer to another.

Disadvantages of floppy disks:

 Floppy disk is not durable (due to dust and dirt) and can be destroyed by
magnetic field.

 Access time of floppy disk is slow (about 84 ms).

 Storage capacity of floppy disk is limited (only 1.44 MB).

16. Explain Optical disk, CD-ROM, WORM and Erasable optical disk.
Ans: Optical Disk: An optical disk is a compact disk or CD. The formatting of the optical disk
will dictate whether it is a DVD, CD, read-only or rewritable. Optical disks have replaced vinyl
records, cassette tapes, videotapes and floppy disks.
The optical disk became the preferred medium for music, movies and software programs
because of its many advantages. Compact, lightweight, durable and digital, the optical disk also
provides a minimum of 650 megabytes (MB) of data storage. A double-layered and double-sided
DVD optical disk holds up to 15.9 gigabytes (GB) of data.

There are three forms of optical disks available:

 CD-ROM: CD-ROM (compact disk read only memory) is an optical disk storage that contains
text, graphics and hi-fi stereo sound. CD-ROM is available in different capacity. In CD- ROM
standard, data (text or pictures) cannot be viewed with audio play simultaneously. CD-ROM XA
standard can do.
 WORM: A WORM (write once, read many) disk is an optical disk that written on just once by
the user's environment and then cannot be overwritten. A WORM disk is ideal for use as archive
because it can be read many times, but the data cannot be erased. The storage capacity of
WORM disk ranges from 400 MB to 6.4 GB.
 Erasable Optical Disks: This is an optical disk that can be erased and written on repeatedly. An
erasable optical disk has a great deal of data capacity. It can store up to 4.6 GB. An erasable
optical disk functions like a magnetic disk and has huge capacity, so it will replace the magnetic
disk in the future.

17.What is internal processor memory?

Ans: Internal processor memory: Basically it comprises of a small set of high-speed register used as a
working memory for temporary storage of instructions and data. Some microprocessors also employ
another type of built-in memory called cache.

18.Write short notes on Hard disc. What are the advantages and disadvantages of Hard disc?

Ans: Hard disc: A hard disk drive (often shortened as hard disk,
hard drive, or HDD) is a non-volatile storage device that stores
digitally encoded data on rapidly rotating rigid (i.e. hard) platters with magnetic surfaces. Strictly
speaking, "drive" refers to the motorized mechanical aspect that is distinct from its medium, such as a tape
drive and its tape, or a floppy disk drive and its floppy disk.

Early HDDs had removable media; however, an HDD today is typically a sealed unit (except for a
filtered vent hole to equalize air pressure) with fixed media.
Advantages of Hard disc:
 Large storage capacity
 Stores and retrieves data much faster than a floppy disk or CD-ROM
 Data is not lost when you switch off the computer
 Usually fixed inside the computer so cannot get mislaid.
 Cheap on a cost per megabyte compared to other storage media.
 Hard disks can be replaced and upgraded as necessary
 Can have two hard disks in a machine, one can act as a mirror of the other and create a back up
copy.

Disadvantages of Hard disc:

 Hard disks eventually fail which stops the computer from working.
 Regular 'head' crashes can damage the surface of the disk, leading to loss of data in that
sector.
 The disk is fixed inside the computer and cannot easily be transferred to another computer.

19.What is cache memory?

Ans: Cache Memory: The speed of CPU is extremely high compared to the access time of main memory.
Therefore the performance of CPU decreases due to the slow speed of main memory. To decrease the
mismatch in operating speed, a small memory chip is attached between CPU and Main memory whose
access time is very close to the processing speed of CPU. It is called CACHE memory. CACHE memories
are accessed much faster than conventional RAM. It is used to store programs or data currently being
executed or temporary data frequently used by the CPU. So each memory makes main memory to be faster
and larger than it really is. It is also very expensive to have bigger size of cache memory and its size is
normally kept small.

Chapter 6
Processing and
Representing Data
1. What are bit, byte, word and length?
Ans: Bit: A bit is the basic unit of information in computing and telecommunications; it is the amount of
information that can be stored by a digital device or other physical system that can normally exist in only
two distinct states. These may be the two stable positions of an electrical switch, two distinct voltage or
current levels allowed by a circuit, two distinct levels of light intensity, two directions of magnetization or
polarization, etc.

Byte: Abbreviation for binary term, a unit of storage capable of holding a single character. On almost all
modern computers, a byte is equal to 8 bits. Large amounts of memory are indicated in terms of kilobytes
(1,024 bytes), megabytes (1,048,576 bytes), and gigabytes (1,073,741,824 bytes).

Or: In most computer systems, a byte is a unit of data that is eight binary digits long. A byte is the unit
most computers use to represent a character such as a letter, number, or typographic symbol (for example,
"g", "5", or "?"). A byte can also hold a string of bits that need to be used in some larger unit for application
purposes

Word: In computing, word is a term for the natural unit of data used by a particular computer design. A
word is simply a fixed sized group of bits that are handled together by the system. The number of bits in a
word (the word size or word length) is an important characteristic of computer architecture.
Modern computers usually have a word size of 16, 32 or 64 bits but many other sizes have been used,
including 8, 9, 12, 18, 24, 36, 39, 40, 48 and 60 bits.

Length: The number of bits in a word is called the word size or word length.

2.What text codes? Give examples.

Ans: Text Codes: Early programmers realized that they needed a standard text code that was agreeable to
all of them. In such a system, numbers would represent the letters of the alphabet, punctuation marks, and
other symbols is known as text code.
There are four most popular text codes are as-
 EBCDIC
 ASCII
 Extended ASCII
 Unicode
3.What are ASCII code, BCD code, Alphanumeric code, EBCDIC code and Unicode?
Ans: ASCII code: The American Standard Code for Information Interchange is a character-encoding
scheme based on the ordering of the English alphabet.
ASCII codes represent text in computers, communications equipment, and other devices that use text. Most
modern character-encoding schemes are based on ASCII, though they support many more characters than
did ASCII.

Alphanumeric code: In general, in computing, an alphanumeric code is a series of letters and numbers
(hence the name) which are written in a form that can be processed by a computer. Specifically, in
computer underground terminology, alphanumeric code is machine code that is written so that it assembles
into entirely alphanumeric ASCII characters such as 0-9, A-Z and a-z. This type of encoding was created
by hackers to be able to pass machine code through a filter that removes any non-alphanumeric character
and still be able to have it perform its intended tasks successfully. (Because normal machine code
frequently uses non-alphanumeric characters, these would get removed by such a filter and the code would
not be able to pass the filter without being modified to the point where it no longer works). A slightly less
restrictive form of this type of encoding is printable code, which uses all printable characters such as 0-9,
A-Z, a-z, !@#%^&*() etc... It has been shown that it is possible to create shellcode that looks like normal
text in English.
EBCDIC code: Extended Binary Coded Decimal Interchange Code (EBCDIC) is an 8-bit character
encoding (code page) used on IBM mainframe operating systems such as z/OS, OS/390, VM and VSE, as
well as IBM midrange computer operating systems such as OS/400 and i5/OS (see also Binary Coded
Decimal). It is also employed on various non-IBM platforms such as Fujitsu-Siemens' BS2000/OSD, HP
MPE/iX, and Unisys MCP. EBCDIC descended from the code used with punched cards and the
corresponding six bit binary-coded decimal code used with most of IBM's computer peripherals of the late
1950s and early 1960s.

Unicode: Unicode is a computing industry standard for the consistent representation and manipulation of
text expressed in most of the world's writing systems. Developed in conjunction with the Universal
Character Set standard and published in book form as The Unicode Standard, the latest version of Unicode
consists of a repertoire of more than 107,000 characters covering 90 scripts, a set of code charts for visual
reference, an encoding methodology and set of standard character encodings, an enumeration of character
properties such as upper and lower case, a set of reference data computer files, and a number of related
items, such as character properties, rules for normalization, decomposition, collation, rendering, and
bidirectional display order (for the correct display of text containing both right-to-left scripts, such as
Arabic or Hebrew, and left-to-right scripts).

4.Describe numbering system. Define types of numbering system.

Ans: Any system of naming or representing numbers, as the decimal system or the binary system is called
numbering system.
Different types of numbering system are:
 Decimal
 Binary
 Octal
 Hexadecimal
 BCD

5.Write the bases, digits and the examples of number system.

Ans:

Examples:

6.Number Conversion technique with example.

 D ===> B, O, H
B ===> D, O, H
O ===> D, B, H
H ===> D, B, O

(A). Decimal to Binary Conversion: (109.78125)10 = (?)2

109 ÷ 2 = 54 ---- 1
54÷ 2 = 27 ---- 0
27÷ 2 = 13 ---- 1
13 ÷ 2 =6 ---- 1
6÷2 = 3 ---- 0
3÷ 2 =1 ---- 1
1÷ 2 = 0 ---- 1
---------------------------------------------------
0.78125× 2 = 1.56250 ---- 1
0. 56250 × 2 = 1.1250 ---- 1
0. 1250 × 2 = 0.250 ---- 0
0. 250 × 2 = 0.50 ---- 0
0.50× 2 = 1.00 ---- 1

.˙. (109.78125)10 = (1101101.11001)2

(B). Decimal to Octal Conversion: (952.450)10 = (?)8

952 ÷ 8 = 119 ---- 0

119 ÷ 8 = 14 ---- 7
14 ÷ 8 = 1 ---- 6
1÷8 = 0 ---- 1
---------------------------------------------
0.450 × 8 =3.600 ---- 3
0.600 × 8 =4.800 ---- 4
0.800 × 8 =6.400 ---- 6
0.400 × 8 =3.200 ---- 3
0.200 × 8 =1.600 ---- 1

.˙. (952.450)10 = (1670.34631)8

(C). Decimal to Hexadecimal Conversion: (428)10 = (?)16

4 28÷16 = 26 ---- 12 =C
26 ÷16 = 1 ---- 10= A
1÷16 =0 ---- 1

.˙. (428)10 = (1AC)16

(D). Binary to Decimal Conversion: (110101.101)2 = (?)10

110101.101 = 1×25 + 1×24+ 0×23 + 1×22 + 0×21 +

 1×20 + 1×2-1 + 0×2-2+ 1×2-3

= 32+16+0+4+0+1 + 0.5+0+0.125

= 53.625

.˙. (110101.101)2 = (53.625)10

(E). Binary to Octal Conversion: (1101010)2 = (?)8

1101010 = 001 101 010
= 152
.˙. (1101010)2 = (152)8

(F). Binary to Hexadecimal Conversion: (11010011)2 = (?)16

1101 0011 = 13 3 = D 3

.˙. (11010011)2 = (D3)16

(G). Octal to Decimal Conversion: (31321)8 = (?)10

31321 = 3 × 8 4 + 1 × 83+ 3 × 82 + 2 × 81 + 1 × 80

= 3 × 4096 + 1 × 512 + 3 × 64 + 2 × 8 + 1 × 1

= 12288 + 512 + 192 + 16 + 1

= 13009

.˙. (31321)8 = (13009)10

(H). Octal to Binary Conversion: (562)8 = (?)2

562 = 101 110 010
= 101110010

.˙. (562)8 = (101110010)2

(I). Octal to Hexadecimal Conversion: (435)8 = (?)16

.˙. (435)8 = (11D)16

(J). Hexadecimal to Decimal Conversion: (3ABE)16 = (?)10

3ABE = 3 × 163 + (A)10 × 162 + (B)11 ×

161 + (E)14 × 160

= 3 × 4096 + 10 × 256 + 11 × 16 + 14 × 1
 = 12288 + 2560 + 176 + 14

= 15038

.˙. (3ABE)16 = (15038)10

(K). Hexadecimal to Binary Conversion: (2AB)16 = (?)2

2AB = 0010 1010 1011
.˙. (2AB)16 = (001010101011)2

(L). Hexadecimal to Octal Conversion: (1DEA)16 = (?)8

1DEA = 0001 1101 1110 1010

= 000 001 110 111 101 010
= 0 1 6 7 5 2

.˙. (1DEA)16 = (016752)8

Chapter 7
Networks and Data
Communications
1.What is computer Network? What are the functions of computer network?

Ans: Computer network: A computer network is an interconnection of various computer systems located
at different places. In computer network two or more computers are linked together with a medium and
data communication devices for the purpose of communicating data and sharing resources. The computer
that provides resources to other computers on a network is known as server. In the network the individual
computers, which access shared network resources, are known as workstations or nodes.

2.What is the classification of computer network? Explain each network.

Ans: Computer Networks may be classified on the basis of geographical area in two broad categories.

 Local Area Network (LAN)

 Metropolitan Area Network(MAN)

 Wide Area Network (WAN)

LAN: A local area network (LAN) is a computer network covering a small physical area, like a home,
office, or small groups 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
area, and lack of a need for leased telecommunication lines.

MAN : A metropolitan area network (MAN) is a large computer network that usually spans a city or a
large campus. A MAN usually interconnects a number of local area networks (LANs) using a high-capacity
backbone technology, such as fiber-optical links, and provides up-link services to wide area networks and
the Internet.

WAN: A wide area network (WAN) is a computer network that covers a broad area (i.e., any network
whose communications links cross metropolitan, regional, or national boundaries [1]). This is in contrast
with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or
metropolitan area networks (MANs) which are usually limited to a room, building, campus or specific
metropolitan area (e.g., a city) respectively.
WANs are used to connect LANs and other types of networks together, so that users and computers in one
location can communicate with users and computers in other locations.
3.What do mean by intranet and internet?
Ans: Intranet: An intranet is a private computer network that uses Internet Protocol technologies to
securely share any part of an organization's information or network operating system within that
organization.

Internet: The Internet is a global system of interconnected computer networks that use the standard
Internet Protocol Suite (TCP/IP) to serve billions of users worldwide. It is a network of networks that
consists of millions of private, public, academic, business, and government networks of local to global
scope that are linked by a broad array of electronic and optical networking technologies. The Internet
carries a vast array of information resources and services, most notably the inter-linked hypertext
documents of the World Wide Web (WWW) and the infrastructure to support electronic mail.

4.What is computer network topology? Write the names of different topologies and draw their
diagram.

Ans: Network Topology: The term topology in the context of communication network refers to the way
the computers or workstations in the network are linked together.

According to the physical arrangements of workstations and nature of work, there are various types of
network topologies are:

 Star topology

 Bus topology

 Ring topology.

 Tree topology

 Mess topology.
NODE
Star topology

In star topology a number of workstations (or nodes) are directly linked to a

CENTRAL NODE
central node (see, Fig. 4.3). Any communication between stations on a star LAN must pass through the
central node. There is bi-directional communication between various nodes. The central node controls all
the activities of the nodes. The advantages of the star topology are:

 It offers flexibility of adding or deleting of workstations from the network.

 Breakdown of one station does not affect any other device on the network.
The major disadvantage of star topology is that failure of the central node disables communication
throughout the whole network.

Bus Topology
Bus Node

In bus topology all workstations are connected to a single

communication line called bus. In this type of network
topology there is no central node as in star topology.
Transmission from any station travels the length of the bus in
both directions and can be received by all workstations. The
advantage of the bus topology is that

 It is quite easy to set up.

 If one station of the topology fails it does not affect the entire system.
The disadvantage of bus topology is that any break in the bus is difficult to identify.

Ring Topology

In ring topology each station is attached nearby stations on a point to point basis so that the entire system is
in the form of a ring. In this topology data is transmitted in one
direction only. Thus the data packets circulate along the ring in either
clockwise or anti-clockwise direction. The advantage of this
topology is that any signal transmitted on the network passes through
all the LAN stations. The disadvantage of ring network is that the
breakdown of any one station on the ring can disable the entire
system.

Mess Topology: Mesh Network is a network where all the nodes are
connected to each other and is a complete network. In a Mesh Network every node is connected to other
nodes on the network through hops. Some are connected through single hops and some may be connected
with more than one hope.

Tree Topology: Among all the Network Topologies we can

derive that the Tree Topology is a combination of the bus and the
Star Topology. The tree like structure allows you to have many
servers on the network and you can branch out the network in many ways. This is particularly helpful for
colleges, universities and schools so that each of the branches can identify the relevant systems in their own
network and yet connect to the big network in some way.

5.Mention the layers of OSI and state their functions.

Ans: The OSI, or Open System Interconnection, model defines a networking framework for implementing
protocols in seven layers. Control is passed from one layer to the next, starting at the application layer in
one station, proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.

 Application (Layer 7): This layer supports application and end-user processes. Communication
partners are identified, quality of service is identified, user authentication and privacy are
considered, and any constraints on data syntax are identified.
 Presentation (Layer 6): This layer provides independence from differences in data representation
(e.g., encryption) by translating from application to network format, and vice versa. The
presentation layer works to transform data into the form that the application layer can accept
Figure: OSI layers
 Session (Layer 5): This layer establishes, manages and terminates connections between
applications
 Transport (Layer 4): This layer provides transparent transfer of data between end systems, or
hosts, and is responsible for end-to-end error recovery and flow control. It ensures complete data
transfer.
 Network (Layer
3): This layer
provides switching
and routing
technologies,
creating logical
paths, known as
virtual circuits, for
transmitting data
from node to node
 Data Link (Layer
2): At this layer,
data packets are
encoded and
decoded into bits. It
furnishes
transmission
protocol knowledge
and management and handles errors in the physical layer, flow control and frame synchronization
checking
 Physical (Layer 1): This layer conveys the bit stream - electrical impulse, light or radio signal --
through the network at the electrical and mechanical level

6.Mention the differences between OSI and TCP/IP.

7.What do you mean by networking media?

Ans: Network media (sometimes referred to as networked media) refers to media mainly used in computer
networks such as the Internet
8.What do mean by network hardware?.
Ans: Networking hardware typically refers to equipment facilitating the use of a computer network.
Typically, this includes
 Routers: A router is a small hardware device that joins multiple networks together. These
networks can include wired or wireless home networks, and the Internet.
 Switches: A network switches is a small hardware device that join multiple computers together at
a low-level network protocol layer. Switches differ in capability from both hubs and routers.
 Hubs: A hub is a very simple hardware device that supports basic file sharing between computers
connected with network cables
 Gateways: A device sitting at a network node for interfacing with another network that uses
different protocols. Works on OSI layers 4 to 7.
 Access points: In a wireless local area network (WLAN), an access point is a station that
transmits and receives data (sometimes referred to as a transceiver). An access point connects
users to other users within the network and also can serve as the point of interconnection between
the WLAN and a fixed wire network. Each access point can serve multiple users within a defined
network area; as people move beyond the range of one access point, they are automatically handed
over to the next one. A small WLAN may only require a single access point; the number required
increases as a function of the number of network users and the physical size of the network.
 Network interface cards: A network interface card, more commonly referred to as a NIC, is a
device that allows computers to be joined together in a LAN, or local area network. Networked
computers communicate with each other using a given protocol or agreed-upon language for
transmitting data packets between the different machines, known as nodes. The network interface
card acts as the liaison for the machine to both send and receive data o n the LAN.
 Networking cables: Networking Cables are used to connect one network device to other or to
connect two or more computers to share printer, scanner etc. Different types of network cables like
Coaxial cable, Optical fiber cable, Twisted Pair cables are used depending on the network's
topology, protocol and size. The devices can be separated by a few meters (e.g. via Ethernet) or
nearly unlimited distances (e.g. via the interconnections of the Internet).
  Network bridges: In computer networking, a bridge divides a LAN into two segments, selectively
forwarding traffic across the network boundary it defines. A bridge is not quite the same as a
switch.
 Modems: A modem (modulator-demodulator) is a device that modulates an analog carrier signal
to encode digital information, and also demodulates such a carrier signal to decode the transmitted
information. The goal is to produce a signal that can be transmitted easily and decoded to
reproduce the original digital data. Modems can be used over any means of transmitting analog
signals, from driven diodes to radio.
 ISDN adapters: ISDN adapters are devices required to establish an ISDN or integrated services
digital network connection – a digital connection that offers a faster option to transmitting data
than the traditional modem.
 Firewalls: A firewall is a part of a computer system or network that is designed to block
unauthorized access while permitting authorized communications. It is a device or set of devices
which is configured to permit or deny computer applications based upon a set of rules and other
criteria.

There are several types of firewall techniques:

 Packet filter
 Application gateway

 Circuit-level gateway

 Proxy server

9.Write on internetwork, repeater.

Ans: Internetwork: Internetworking is the practice of connecting a computer network with other networks
through the use of gateways that provide a common method of routing information packets between the
networks. The resulting system of interconnected networks is called an internetwork, or simply an internet.

Repeaters: Repeaters extend the distance a network can span by ensuring good signal quality.

10.What is data communication model?

Communication is the conveyance of a message from one entity, called the source or transmitter, to
another, called the destination or receiver, via a channel of some sort.

A simple example of such a communication system is conversation; people commonly exchange verbal
messages, with the channel consisting of waves of compressed air molecules at frequencies which are
audible to the human ear.
11.What is protocol?

Ans: In computing protocol or communications protocol is a formal description of message formats and
the rules for exchanging those messages. Protocols may include signaling, authentication and error
detection and correction capabilities. In its simplest form, a protocol can be defined as the rules governing
the syntax, semantics, and synchronization of communication. Protocols may be implemented by hardware,
software, or a combination of the two. At the lowest level, a protocol defines the behaviour of a hardware
connection.

Chapter 8
Internet and Online
Resources
1.Write down the historical evolution of the Internet?

Ans: Historical evolution of the Internet : The Internet has its root in the ARPANET system of the
Advanced Research Project Agency of U.S Department of Defense. ARPANET was the first WAN and had
only four sites in 1969. The Internet evolved from the basic ideas of ARPANET for interconnecting
computers, and was initially used by research organizations and universities to share and exchange
information. In 1989 the U.S. Government lifted restrictions on the use of the Internet, and allowed it to be
used for commercial purpose as well. Since then the Internet has rapidly grown to become the world’s
largest network. It now interconnects more than 30,000 networks, allowing more than 10 million
computers, and more than 50 million computer users in more than 150 countries around the world to
communicate with each other. The Internet continues to grow at a rapid pace.

2.How Internet works?

Ans: Because the Internet is a global network of computers each computer connected to the Internet must
have a unique address. Internet addresses are in the form nnn.nnn.nnn.nnn where nnn must be a number
from 0 - 255. This address is known as an IP address. (IP stands for Internet Protocol; more on this later.)

The picture below illustrates two computers connected to the Internet; your computer with IP
address 1.2.3.4 and another computer with IP address 5.6.7.8. The Internet is represented as an
abstract object in-between. (As this paper progresses, the Internet portion of Diagram 1 will be
explained and redrawn several times as the details of the Internet are exposed.)

Figure 8.1 Internet

If you connect to the Internet through an Internet Service Provider (ISP), you are usually assigned a
temporary IP address for the duration of your dial-in session. If you connect to the Internet from a local
area network (LAN) your computer might have a permanent IP address or it might obtain a temporary one
from a DHCP (Dynamic Host Configuration Protocol) server. In any case, if you are connected to the
Internet, your computer has a unique IP address.

3.What are the Internet services?

Ans: The Internet services are:

Information: Many people use the terms Internet and World Wide Web, or just the Web,
interchangeably, but the two terms are not synonymous. The World Wide Web is a global set of
documents, images and other resources, logically interrelated by hyperlinks and referenced with Uniform
Resource Identifiers (URIs).

Communication: E-mail is an important communications service available on the Internet. The

concept of sending electronic text messages between parties in a way analogous to mailing letters or
memos predates the creation of the Internet. Pictures, documents and other files can be sent as e-mail
attachments. E-mails can be cc-ed to multiple e-mail addresses.

Internet telephony is another common communications service made possible by the creation of the
Internet. VoIP stands for Voice-over-Internet Protocol, referring to the protocol that underlies all Internet
communication.

Data transfer: File sharing is an example of transferring large amounts of data across the Internet. A
computer file can be e-mailed to customers, colleagues and friends as an attachment. It can be
uploaded to a website or

server for easy download by others. It can be put into a "shared location" or onto a file server for
instant use by colleagues.

Streaming media refers to the act that many existing radio and television broadcasters promote Internet
"feeds" of their live audio and video streams (for example, the BBC

4.What are the Internet address and DNS?

Ans: Internet address : An Internet address uniquely identifies a node on the Internet. Internet address
may also refer to the name or IP of a Web site (URL). The term Internet address can also represent
someone's e-mail address.

DNS: The Domain Name System (DNS) is a hierarchical naming system for computers, services,
or any resource connected to the Internet or a private network. It associates various information with
domain names assigned to each of the participants. Most importantly, it translates domain names
meaningful to humans into the numerical (binary) identifiers associated with networking equipment for the
purpose of locating and addressing these devices worldwide. An often-used analogy to explain the Domain
Name System is that it serves as the "phone book" for the Internet by translating human-friendly computer
hostnames into IP addresses. For example, www.example.com translates to 192.0.32.10.

5.Mention the features of Internet.

Ans: The features of Internet are:

a. Geographic Distribution
b. Robust Architecture

c. Near Light Speed

d. Universal Access

e. Internet Growth Rates

f. The Digital Advantage

g. Freedom Of Speech

6.What do you mean by WWW?

Ans: WWW : The World Wide Web, abbreviated as WWW and commonly known as The Web, is a
system of interlinked hypertext documents contained on the Internet. With a web browser, one can
view web pages that may contain text, images, videos, and other multimedia and navigate between
them by using FTP hyperlinks.

Using concepts from earlier hypertext systems, British engineer and computer scientist Sir Tim Berners
Lee, now the Director of the World Wide Web Consortium, wrote a proposal in March 1989 for what
would eventually become the World Wide Web. He was later joined by Belgian computer scientist Robert
Cailliau while both were working at CERN in Geneva, Switzerland. In 1990, they proposed using
"HyperText [...] to link and access information of various kinds as a web of nodes in which the user can
browse at will", and released that web in December.

7.How one can access to the Internet?

Ans: There are four ingredients needed to access the Internet

(1) An ISP,

(2) A modem,

(3) A Web browser and

(4) An e-mail program.

The Internet Service Provider (ISP):

Your access to the Internet is through an Internet service provider (ISP), which can be a large company
such as America Online or MSN, or any of hundreds of smaller ISPs throughout the country. You are
offered unlimited access for a fixed rate per month.

The Modem:

Depending on the kind of service you have, you will need a unit of hardware called a "modem" for
connection. Slow-speed dial-up telephone access uses an analog modem, which may already be installed in
your computer. If not, one can be plugged into the USB port.

If you sign up for cable or DSL service, which is from 40 to 100 times faster than telephone dial-up, your
provider may send you the appropriate modem, or you can purchase it at your local electronics store. Quite
simply, opt for the high-speed service if you can. Dial-up modems are an exercise in extreme patience.

Browsing the Web:

A Windows PC comes with the Internet Explorer Web browser. The Mac comes with Safari. Windows
users quite often choose a different browser such as Firefox (www.mozilla.org) or Opera
(www.opera.com), which offer additional features and are not as subject to attack by hackers. Likewise,
Mac users may opt for Firefox.

The first time you hook up to a new ISP, you may need their assistance to configure the dial-up or
networking software in your computer. After that, all you do is launch the browser, and you are "surfing the
Web."

Sending E-Mail:

Your computer also comes with an e-mail program to send and receive mail. Windows comes with
Outlook, and the Mac comes with Mail, although many users choose Eudora or Thunderbird, other popular
e-mail clients. The first time you connect to a new ISP, you may need help in configuring your e-mail
program to use their mail servers. From then on, you launch the mail program as you would any other.

8.What is ergonomics?

Ans: Ergonomics is the science of adjusting work environment to fit your body and make it most
comfortable.
 Chapter 9
Living with computer
1.What is meant by computer piracy?

Ans: Computer piracy: Computer piracy is reproduction, distribution and use of software without
permission of the owner of copyright.

2.What are worm and viruses?

Ans: WORM: A computer worm is a self-replicating Malware computer program. It uses a computer
network to send copies of itself to other nodes (computers on the network) and it may do so without any
user intervention. This is due to security shortcomings on the target computer. Unlike a virus, it does not
need to attach itself to an existing program. Worms almost always cause at least some harm to the network,
if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted
computer.

VIRUS: A computer virus is simply a computer program that does bad things to your computer.

A computer virus is a computer program that can copy itself and infect a computer. The term "virus" is
also commonly but erroneously used to refer to other types of malware, adware, and spyware programs that
do not have the reproductive ability. A true virus can only spread from one computer to another (in some
form of executable code) when its host is taken to the target computer; for instance because a user sent it
over a network or the Internet, or carried it on a removable medium such as a floppy disk, CD, DVD, or
USB drive. Viruses can increase their chances of spreading to other computers by infecting files on a
network file system or a file system that is accessed by another computer.

3.Explain the process for transmitting a virus, damage from viruses and prevention from viruses?

Ans: Process for transmitting a virus:

 A virus may transmit by-
 E-mails or e-mail attachments
 Internet downloads
 Web pages
 Software releases on disc or CD

Process for damage from viruses:

Generally, it is not possible for viruses to cause direct physical damage to your computer. However, they
can cause information stored on the hard disk to be lost, monitor your computing activities, and/or make
applications function improperly. They can also put stress on some parts of the computer by causing them
to work more frequently, like the hard disk, processor, and variable-speed fans. Probably the most
significant possibility for a virus to actually cause damage to computers is if it improperly re-formats their
hard disks. Computers which have less commonly used operating systems (like Mac OS, Linux, or DOS)
tend to be less susceptible to viruses.

Process for prevention from viruses:

Install an antivirus program and keep it updated. University Technology Services has purchased a volume
license for antivirus software and made it available for download by students, staff and faculty.

Keeping antivirus programs updated is imperative. Because new viruses are released every day, there's
always some risk that your computer will be infected by a virus that your antivirus program does not
"know" about. Unless a rapidly-spreading virus is released, you should be reasonably safe if you update
your antivirus program weekly.

4.Explain the hardware affects to computer?

Ans: Hardware affects: Hardware affects means the hardware role. It is very essential to computer or any
electrical equipment.
Hardware affects to computer can be point as:
 Without hardware the computer cannot be imagine
 .If any hardware damaged the system will not work.
 If the hardware capacity is less, then the performance will be low
 If anyone can get high he must upgrade his hardware capacity.
5.Mention the issues for data theft.
Ans: Issues for data theft: Data theft is a growing problem primarily perpetrated by office workers with
access to technology such as desktop computers and hand-held devices capable of storing digital
information such as flash drives, iPods and even digital cameras. Since employees often spend a
considerable amount of time developing contacts and confidential and copyrighted information for the
company they work for they often feel they have some right to the information and are inclined to copy
and/or delete part of it when they leave the company, or misuse it while they are still in employment.

6.What are the ethical issues of computer?

Ans: Many ethical issues have arisen as a result of the increasing use of computers and computer
technologies. Most of the issues can be classified and analyzed using traditional ethical concepts such as
property, responsibility, rights, and authority, and most involve relationships that exist independent of
computers – employer/employee, citizen/government, producer/vendor/consumer, professional/client,
professional/society. Nevertheless, when a situation involves computers it takes on special features that
may transform its moral character or create uncertainty about norms, rights, and responsibilities. The
special features of the situation necessitate a rethinking of traditional norms and values, a new
understanding of how traditional values and norms apply. Hence, it seems fitting to call the issues new
species of generic moral issues. The new and old in computer ethical issues can be illustrated using the
threat to personal privacy that computer technology seems to create. Information about individuals was
being gathered and kept in increasing quantities by government and business for centuries before
computers were invented. Still, the development of computer technology facilitated a radically increased
scale of record keeping. It has facilitated an increased level of exchange of information about individuals
(increased speed of exchange, quantity of information being exchanged

Chapter 10
Word processing using
MS-Word
1.What is MS-Word? What are done with MS-Word?

Ans: Microsoft Word is a word processor designed by Microsoft. It was first released in 1983 under the
name Multi-Tool Word for Xenix systems. Subsequent versions were later written for several other
platforms including IBM PCs running DOS (1983), the Apple Macintosh (1984), the AT&T Unix PC
(1985), Atari ST (1986), SCO UNIX, OS/2, and Microsoft Windows (1989). It is a component of the
Microsoft Office system; however, it is also sold as a standalone product and included in Microsoft Works
Suite. Beginning with the 2003 version, the branding was revised to emphasize Word's identity as a
component within the Office suite on PC versions; Microsoft began calling it Microsoft Office Word
instead of merely Microsoft Word. The 2010 version appears to be branded as Microsoft Word, once again.
The current versions are Microsoft Office Word 2007 for Windows and 2008 for Mac. In late 2009,
Microsoft released the beta version of Microsoft Word 2010

2.What are needs to run MS-Word in a computer?

Ans: To run MS-Word in a computer needs:

 Active Computer
 MS Office program Installation
3.Write the process for creating a document.

Ans: Process for creating a document:

 Power the computer

 Run MS Word in computer

 Write something in text area

 Save the document

4.Write the process for saving a document.

Ans: Process for saving a document:

 Create the document

 Go to File menu

 Select Save Option

 Select file name and location

 Click Save

5.What is meant by editing?

Ans: Editing is the process of selecting and preparing language, images, sound, video, or film through
processes of correction, condensation, organization, and other modifications in various media. A person
who edits is called an editor. In a sense, the editing process originates with the idea for the work itself and
continues in the relationship between the author and the editor. Editing is, therefore, also a practice that
includes creative skills, human relations, and a precise set of methods.

6.Write the process for copying and pasting a section in a document.

Ans: Process for copying and pasting a section in a document:

 Open the document.
 Select the document area by mouse(drug and drop) or keyboard(by shift + arrow key)
you want to copy.
 Select Edit Menu, Select Copy / Press Ctrl + C.
 Now go to desired location you want to Paste.
 Now Select Edit Menu, Select Paste / Press Ctrl + V.


7.Write the process for spell checking a document.

Ans: Process for spell checking a document:

 Open Microsoft Word and the document you wish to edit.

 Click Tools

 Click Spelling and Grammar

Following the above steps will start a spell check on the document you're viewing. Each spelling error that
is found will have the option to be changed to available suggestions. If the word is spelled correctly, Ignore
the word; if the word is misspelled and you believe that this spelling error is made throughout your
document, Change All; and if you wish to simply change the word to an alternate spelling, click one of the
suggestions from the suggestion list and click Change.

8.Write the process for creating a table and manipulating it.

Ans: Process for creating a table and manipulating it:

 Start a new Word document

 From the menu bar, click on Table

 From the menu that drops down, click Insert

 A sub menu appears

 From the sub menu, click Table

When you click Insert > Table you get a dialogue box popping up. This one below:
The table we're going to draw has 8 columns and 2 rows. So change the Number of columns to 8. Then
click the OK button. Your page will look like this:

9.Write the process for printing a document.

Ans: Process for printing a document:

 Create the document / Open the document

 Select File menu, Select Print / Press Ctrl+P

 Select all / Current page /pages

 Select No of copies

 Click Ok/Enter

10. Write the process for setting header and footer in MS-Word?.

Ans: To apply header or footer in MS-Word , following are the steps.

 Select "Header and Footer" from View menu, "Header and Footer" Floating Toolbar will appear.
The header and footer sections of document are also activated.
 Type Information for Header and Footer in area identified in top and bottom margins.

 Select other options if required from Toolbar box and click Close button of Toolbar.

Chapter 11
 Spreadsheet using MS-
Excel
1.What is MS-Excel? What are done with MS-Excel?

Ans: Microsoft Excel (full name Microsoft Office Excel) is a spreadsheet application written and
distributed by Microsoft for Microsoft Windows and Mac OS X. It features calculation, graphing tools,
pivot tables and a macro programming language called VBA (Visual Basic for Applications). It has been
the most widely used spreadsheet application available for these platforms since version 5 in 1993. Excel
forms part of Microsoft Office. The current versions are Microsoft Office Excel 2007 for Windows and
2008 for Mac. In late 2009, Microsoft released the beta version of Microsoft Excel 2010.

2.What are needs to run MS-Excel in a computer?

Ans: To run MS-Excel in a computer needs:

 Active Computer
 MS Office program Installation

3.Write the process for creating a worksheet.

Ans: Process for creating a worksheet:

 Power the computer

 Run MS Excel in computer

 Write something in worksheet

 Save the document

4.Write the process for saving a worksheet.

Ans: Process for saving a worksheet:

 Create the worksheet

 Go to File menu

 Select Save Option

 Select file name and location

  Click Save

5.What is process for creating a formula?

Ans: Process for creating a formula:

 Start Microsoft Excel and open the file you want to change.
 Double-click on the cell where you want the total to appear.

 Press the = key on the keyboard. This tells Excel that you are entering a formula into the cell.

 Enter the formula, then press Enter. Follow the steps below for an example.

 Enter an opening parenthesis character: (.

 Enter a cell name. For example: =(E2.

 Press the + key.

 Enter another cell name and a closing parenthesis character: ). For example: =(E2+E3).

 Enter a minus sign and a third cell name. For example: =(E2+E3)-E4.

 Press the Enter key to accept the formula. The cell will display the sum of the first two cells minus
the third cell.

6.Write the MS-Excel functions?

 Excel SUM Function = SUM(B7 : B10)

 Excel Auto SUM ∑

 Date Function in Excel =TODAY( ) and =NOW( )

 Excel AVERAGE Function = AVERAGE (C1 : C6)

 Excel MAX Function = MAX ( C1 : C6 )

 Excel MIN Function =MIN(C1:C6)

 Excel's COUNT Function =COUNT(C1:C6)

 Excel 2003 ROUND Function = ROUND ( 34.567 , 1 )

 Excel AND Function =AND (B1>100, B2>100, B3>100)

=IF(AND(B1>100,B2>100,B3>100),”Over Budget”,”Acceptable”)

 Excel OR Function =OR (B1>100, B2>100, B3>100)

=IF(OR(B1>100,B2>100,B3>100),”Over Budget”,”Acceptable”)
7.Write the process for creating header and footer in a worksheet.
Ans: Process for creating header and footer in a worksheet:

 Open an Excel Spreadsheet

 Decide Header and Footer Purpose
 Select Excel Header and Footer Dropdowns
 Type Text in the Header or Footer
 Add Date and Time
 Preview the Excel Header and Footer

8.What is chart? What are the charts that are used in MS-Excel?
Ans: Chart: A chart is a group of related facts presented in the form of a diagram, table, graph, or other
visually organized model.
Charts that are used in MS-Excel:
 Column
 Bar
 Pie
 XY (Scatter)
 Area
 Doughnut
 Radar
 Surface
 Bubble
 Stock
 Cones
 Floating Bars
 Line
 Logarithmic
9.Write the process for creating a chart.
Ans: Process for creating a chart:
 On the worksheet, arrange the data that you want to plot in a chart.
 Select the cells that contain the data that you want to use for the chart.
 Click Chart Wizard on the Standard toolbar, or click Chart on the Insert menu.
 Follow the instructions in the Chart Wizard.

10.Write the process for printing in MS-Excel.

Ans: Process for printing in MS-Excel:

 Create the worksheet / Open the worksheet

 Select File menu, Select Print / Press Ctrl+P

 Select all / Current page /pages

 Select No of copies

 Click Ok/Enter

11. Write the process for setting header and footer in MS-Excel?.
Ans: The process for setting header and footer in MS-Excel are as:

 Select "Header and Footer" from View menu, "Header and Footer" Floating Toolbar will
appear. The header and footer sections of document are also activated.
 Now under Header/Footer tab, click on Custom Footer button then select left section.
 To insert the picture, click on Picture icon (the 2 nd icon from the right side) to select the
company logo that you want to add.
 Select other options if required, for example you can add date, time file name and file path also.
 Now click Ok button to finish the process.