01 - introduction to computer, Study notes of Computer science

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CONTENTS

• 3. Computer Hardware 20-
• 7. Operating System 63-
• 1. Introduction to Computer 1-
• 6. Computer Software 55-
• 10. Microsoft Office 90-
• 11. Database Concepts 113-
• 12. Data Communication and Networking 122-
• 2. Computer Architecture 12-
• 13. Internet and its Services 132-
• 14. Computer Security 145-
  • Ÿ Glossary 180-
• 5. Data Representation 45-
• 4. Computer Memory 33-
• 9. Microsoft Windows 79-
• 8. Programming Concepts 72-
  • Ÿ Practice Sets (1-5) 156-
  • Ÿ Abbreviations 176-

The word computer has been derived from Latin language. A computer is an electronic device that

manipulates information or data according to the set of instructions. It has the ability to store, retrieve

and process data. A computer is used to type documents, send E-mails and browse the Internet. It is also

used to handle accounting, database management, presentations, games and so on.

Functioning of a Computer

Computer performs four basic functions which are as follows

1. Input Information or data that is entered into a computer is called input. It sends data and

instructions to the Central Processing Unit (CPU).

2. Processing It is the sequence of actions taken on data to convert it into information which is

meaningful to the user. It can be calculations, comparisons or decisions taken by the computer.

3. Output It makes processed data available to the user. It is mainly used to display the desired

result to the user as per input instructions.

4. Storage It stores data and programs permanently. It is used to store information during the time

of program execution and possible to get any type of information from it.

Features of Computer

The key features of computer are as follows

1. Speed The computer can process data very fast at the rate of millions of instructions per second.

2. Accuracy Computers provide a high degree of accuracy. They respond to the user as per the

input instructions.

3. Storage Capacity Computers are capable to store huge amount of data which depends on the

capacity of hard disk.

4. Versatility Computers can do different types of work simultaneously. They can perform multiple

tasks at a same time.

C H A P T E R

INTRODUCTION

TO COMPUTER

Invention Inventor Characteristics Applications

Tabulating Machine 1890

Herman Hollerith (America)

n (^) It used punched cards with round holes. n (^) It was the first electromechanical machine , designed to process the data for census in 1890.

n (^) Read one card at a time.

MARK- 1944

Howard Aiken (America)

n (^) Consists of interlocking panels of small glass, counters, switches and control circuits. n (^) Data can be entered manually.

n (^) Mainly used in the war effort during World War-II. n (^) Magnetic drums are used for storage.

ENIAC 1946

JP Eckert and JW Mauchly (America)

n (^) It is a combination of twenty accumulators. n (^) First electronic digital computer.

n (^) Used for weather prediction, atomic energy calculation and other scientific uses.

EDSAC 1949

John Von Neumann (America)

n (^) It was first computer which provided storage capacity. n (^) First computer program was run on machine.

n (^) Capable of storing instructions and data in memory. n (^) Used mercury delay lines for memory, vacuum tubes for logic.

UNIVAC 1951

J. Presper Eckert and John Mauchly (America)

n (^) First general-purpose electronic computer with large amount of input and output.

n (^) Used magnetic tapes as input and output.

IBM- Computer 1953

IBM Company

n (^) Provided input/output units converting alphabetical and special characters to two-digit decimal code.

n (^) Payroll processing n (^) Oil refinery design n (^) Market research analysis

Generations of Computer

A generation refers to the state of improvement in the development of system. Computers are built of

electromechanical, before generation. Each generation of computer is characterised by a major

technological development that fundamentally changed the way, computers operate.

Generation Switching Device

Storage Device/Speed

Operating System Characteristics Applications

First (1940-56)

Vacuum tubes Magnetic drums (333 micro seconds)

Batch operating system (Machine language (Binary number 0’s and 1’s)

n (^) Fastest computing device. n (^) Generate large amount of heat. n (^) Non-portable.

n (^) Used for scientific purpose e.g. ENIAC, UNIVAC, MARK-1, etc.

Second (1956-63)

Transistors (Made up of semiconductor)

Magnetic core technology (10 micro seconds)

Time sharing OS, Multitasking OS (Assembly language, high level language)

n (^) More reliable and less prone to hardware failure. n (^) Portable and generate less amount of heat.

n (^) Used for commercial production e.g. PDP-8, IBM-1401, etc.

Third (1964-71)

Integrated Circuits (ICs) (Made up of silicon)

Magnetic core as primary storage medium (100 nano seconds)

Real-time system (High level language (FORTRAN, COBOL, ALGOL))

n (^) Consumed less power. n (^) Highly sophisticated technology required.

n (^) Database management system e.g. NCR-395, B6500, etc.

Introduction to Computer 3

4 Learn, Revise & Practice ~^ Computer Awareness

Generation Switching Device

Storage Device/Speed

Operating System Characteristics Applications

Fourth (1971- Present)

Large Scale Integrated (LSI) circuit micro- processor

Semi conductor memory, Winchester disc (300 nano seconds)

Time sharing, GUI interface (PASCAL, ADA, COBOL-74, FORTRAN IV)

n (^) More reliable and portable. n (^) This generation leads to better communication and resource sharing

n (^) Distributed system, e.g. Intel 4004 chip, Macintosh.

Fifth (Present and Beyond)

Super Large Scale Integrated (SLSI) chips

Optical disc Knowledge Information Processing System

n (^) Parallel processing. n (^) Intel core micro- processor is implemented. n (^) Enables mega chips.

n (^) Artificial intelligence e.g. Robotics

n (^) Siddhartha was the first computer developed in India. n (^) Alan Turing is known as the father of the modern computer. n (^) John Von Neumann was introduced first architecture of computer in the year 1948. n (^) Transistors were invented by Bell Laboratory. n (^) In 1958, Jack St. Clair Kilby and Robert Noyce invented the first IC. n (^) In latest generation computers, the instructions are executed parallel as well as sequential.

Classification of Computer

Computers are mainly classified in three types as follows

Based on Size

On the basis of size, computers are categorised as follows

Microcomputer

These types of computers are the least powerful, yet the most widely used and are also called portable

computers. Microcomputer consists of three basic categories of physical equipment, i.e. system unit,

input/output unit and memory unit.

Some types of microcomputer are as follows

(a) Desktop Computer or Personal Computer (PC) These are small, relatively economical

computers. These are based on the microprocessor technology (Integrated Circuit-IC).

(b) Laptop These computers are also known as ultra book or notebook. These are portable and

lightweighted. They include rechargeable battery, so these can work anywhere.

Tit-Bits

Classification of Computer

Based on Size

Microcomputer Supercomputer

Minicomputer

Based on Work

Analog Computer Digital Computer

Hybrid Computer Mainframe Computer

Based on Purpose

General Purpose Computer

Special Purpose Computer

6 Learn, Revise & Practice ~^ Computer Awareness

Special Purpose Computer

Special purpose computers are those computers

which are used to solve a single and dedicated

types of problem. e.g. Automatic aircraft landing,

multimedia computer, etc.

Quantum computer was first introduced by Richard Feynman. It uses quantum mechanical phenomena. It is the fastest computer imitating brain working. Nano computer is a general team used to describe a computer smaller than a microcomputer, usually about the size of a credit card. e.g. Raspberry Pi which could be used in schools to teach science to children. Pratyush India’s fastest and first multi-petaflops (PF) supercomputer named Pratyush was unveiled at Pune- based Indian Institute of Tropical Meteorology (IITM). Pratyush has 6.8 PF computational power installed at two MoES Institutes. 4.0 Peta Flops HPC facility at IITM, Pune and 2.8 Peta Flops facility at NCMRWF, Noida. Pratyush is fourth fastest supercomputer in the world dedicated for weather and climate research. Note PF is a measure of a computer’s processing speed.

Applications of Computer

Some of the areas where computers are being used are

as follows

1. Banking Computers are used in bank for

electronic money transfer, making deposits,

voucher, bank sheet, etc.

2. Education Computer is a very effective tool

which can be used for teaching and learning,

result processing, student data processing,

notes preparation, etc.

3. Entertainment Different types of

entertainment fields such as multimedia, film

making with animation, graphics, audio and

visual design are done with the help of

computer.

4. Offices Computers are used for preparing

reports, storing/deleting reports, updating

reports, etc. in office.

5. Advertisement Computers are used in the

different fields of advertisement such as

business advertisement, film advertisement,

education advertisement, etc.

6. Business Computers are used in business

for accounting, keeping all records up-to

date, etc.

Artificial Intelligence (AI) is an area of computer science that emphasises the creation of intelligent machines that work and react like humans. Some of the activities computers with AI are designed for include : speech recognition, learning, planning, problem solving, etc. Robotics is the branch of engineering and science that deals with the design, construction, operation and use of robots as well as computer systems for their control, sensory feedback and information processing.

1. The word computer has been derived from

which of the following language?

(1) Greek (2) English (3) Hindi (4) Latin

2. Input, output and processing devices

grouped together represent a(n)

(1) mobile device (2) information processing cycle (3) circuit board (4) computer system

3. Which of the following is the correct order

of the four major functions of a computer?

(1) Process, Output, Input, Storage (2) Input, Output, Process, Storage (3) Process, Storage, Input, Output (4) Input, Process, Output, Storage

4. Collecting the data and converting it into

information is called

(1) processing (2) compiling (3) importing (4) exporting (5) None of these

5. Computer cannot perform

(1) input (2) output (3) thinking (4) processing

6. A computer cannot perform which of the

following functions? [IBPS Clerk 2015]

(1) Addition (2) Subtraction (3) Bake a cake (4) Division (5) None of these

7. Part number, description and number of parts

ordered are examples of [IBPS Clerk 2013]

(1) control (2) output (3) processing (4) feedback (5) input

8. Benefits of computers are

(1) very fast and can store huge amount of data (2) provide accurate output either input is correct or not (3) think about the processing (4) All of the above

9. A collection of unprocessed items is

[SBI PO 2015] (1) information (2) data (3) memory (4) reports (5) None of these

10. Which among the following cycle consists

of an input, processing, output and storage

as its constituents? [IBPS Clerk Mains 2017]

(1) Processing (2) Output (3) Input (4) Storage (5) Data

11. ……… is data that has been organised and

presented in a meaningful fashion.

[IBPS Clerk Mains 2017] (1) A process (2) Software (3) Storage (4) Information (5) Data

12. Data or information used to run the

computer is called [IBPS Clerk 2013]

(1) hardware (2) CPU (3) peripheral (4) software (5) None of these

13. The steps and tasks needed to process data,

such as responses to questions or clicking

an icon, are called [IBPS Clerk Mains 2017]

(1) i nstructions (2) the operating system (3) application software (4) the system unit (5) the hardware unit

14. The earliest calculating device is

(1) calculator (2) abacus (3) difference engine (4) analytical engine (5) None of the above

15. Abacus can perform

(1) addition (2) subtraction (3) multiplication (4) Both ‘1’ and ‘2’

QUESTION BANK

36. Integrated Circuit (IC) or chips used in

computers are made with [IBPS Clerk 2014]

(1) copper (2) aluminium (3) gold (4) silicon (5) silver

37. A complete electronic circuit with

transistors and other electronic components

on a small silicon chip is called a(n)

[RBI Grade B 2012] (1) workstation (2) CPU (3) magnetic disc (4) integrated circuit (5) complex circuit

38. PCs are considered fourth-generation and

contain [SBI PO 2014]

(1) information (2) data (3) vacuum tubes (4) microprocessors (5) transistors

39. Artificial Intelligence is an example of

(1) first generation computer (2) second generation computer (3) third generation computer (4) fourth generation computer (5) fifth generation computer

40. First computer of India is

(1) PARAM (2) Siddhartha (3) IBM-370 (4) CRAY-

41. Computer’s basic architecture was

developed by

(1) John Von Neumann (2) Charles Babbage (3) Blaise Pascal (4) Jordan Murn

42. Who developed integrated chip?

(1) Robert Nayak (2) C Babbage (3) JS Kilby (4) CV Raman

43. In latest generation computers, the

instructions are executed

(1) only parallel (2) only sequentially (3) Both ‘1’ and ‘2’ (4) Either ‘1’ or ‘2’

44. Microcomputer hardware consists of three

basic categories of physical equipment

(1) keyboard, monitor, hard drive (2) system unit, input/output, memory (3) system unit, input/output, secondary storage (4) system unit, primary storage, secondary storage

45. Which of the following options correctly

expresses the meaning of the term ‘PCs’?

[IBPS PO 2012] (1) Independent computers for all working staff (2) Personal computers widely available to individual workers with which they can access information from layer systems and increase their personal productivity (3) Packed computers system formed by joining together of various computer terminals (4) Computer manufactured by the Pentium Company (5) None of the above

46. Which of the following is a small micro-

processor based computer designed to be used

by one person at a time? [SBI Clerk 2014]

(1) Netbook (2) Supercomputer (3) All-in-one (4) Notebook (5) Personal computer

47. Tablet PC is a type of

(1) microcomputer (2) supercomputer (3) minicomputer (4) mainframe computer

48. Computers that are portable and convenient

to use for users who travel, are known as

(1) supercomputers (2) minicomputers (3) mainframe computers (4) laptops

49. Desktop and personal computers are also

known as [SBI Clerk 2012]

(1) supercomputers (2) servers (3) mainframes (4) peripheral equipment (5) microcomputers

50. Which of the following uses a handheld

operating system? [SBI PO 2013]

(1) A supercomputer (2) A personal computer (3) A laptop (4) A mainframe (5) A PDA

Introduction to Computer 9

51. Palmtop computer is also known as

(1) personal computer (2) notebook computer (3) tablet PC (4) handheld computer

52. A central computer that holds collections of

data and programs for many PCs,

workstations and other computers is a

(1) supercomputer (2) minicomputer (3) laptop (4) server

53. Which computer is used for Computer

Aided Design (CAD) calculations?

(1) Minicomputer (2) Mainframe computer (3) Supercomputer (4) Microcomputer

54. Which of the following is generally costlier?

[SBI Clerk 2012, IBPS Clerk 2015] (1) Server (2) Notebook computer (3) Personal computer (4) Laptop computer (5) Mainframe

55. The user generally applies ......... to access

mainframe or supercomputer.

(1) terminal (2) node (3) desktop (4) handheld

56. These are specially designed computers that

perform complex calculations extremely

rapidly.

(1) Servers (2) Supercomputers (3) Laptops (4) Mainframes

57. A ......... is a large and expensive computer

capable of performing scientific and

business applications.

(1) supercomputer (2) mainframe computer (3) minicomputer (4) handheld computer

58. First supercomputer developed in India is

(1) PARAM (2) CRAY-

(3) PARAM ISHAN (4) EPRAM

59. Pratyush is …… fastest supercomputer in

the world.

(1) first (2) second (3) third (4) fourth

60. Pratyush supercomputer is dedicated for

(1) multimedia (2) weather forecasting (3) recreation (4) military personnel

61. Which of the following is the India’s first

multi-petaflops (PF) supercomputer?

(1) PARAM (2) Pratyush (3) PARAM Ishan (4) Tianhe-

62. Analog computer works on the supply of

(1) continuous electrical pulses (2) electrical pulses but not continuous (3) magnetic strength (4) physical strength

63. Seismograph is an example of

(1) Analog computer (2) Digital computer (3) Hybrid computer (4) All of thes

64. These computers work by calculating the

binary digits.

(1) Hybrid (2) Digital (3) Analog (4) General purpose

65. Choose the odd one out. [IBPS Clerk 2011]

(1) Microcomputer (2) Minicomputer (3) Supercomputer (4) Digital computer (5) Notebook computer

66. A hybrid computer is the one having the

combined properties of [SBI Clerk 2013]

(1) super and microcomputers (2) mini and microcomputers (3) analog and digital computers (4) super and mini computers (5) None of the above

67. Which types of computer are used in

hospitals like ECG and DIALYSIS?

(1) Digital (2) Hybrid (3) Analog (4) Microcomputer

68. General purpose computers are used for

(1) creating a small database (2) performs calculation (3) accounting (4) All of the above

69. Which is not the example of special purpose

computer?

(1) Automatic aircraft landing (2) Word processor (3) Multimedia computer (4) All of the above

10 Learn, Revise & Practice ~^ Computer Awareness