SEBA Class 9 Computer Science Chapter 1: Basics Of Computer System All Questions & Answers

Basics Of Computer System

Choose the correct option :-

1) Which of the following is not an output device ?

a) Speaker b) Mouse c) Printer d) Monitor

Ans: Mouse

2) Which one of the following is the “brain “ of a computer ?

a) CPU b) ALU c) CU d) MU

Ans: CPU

3) A collection of eight bits is called …………………

a) Byte b) Word c) Record d) Nibble

Ans: Byte

4) Second generation computers were manufactured using which technology?

a) Vacuum tubes b) Transistors c) ICs d) None of these

Ans: Transistors

5) Storage of 1KB means the following number of bytes

a) 1000 b) 1024 c) 1064 d) 1012

Ans: b) 1024

6) Which of the following is not a hardware?

a) Hard disk b) Printer c) Assembler d) CPU

Ans: Assembler

7) Fourth generation computers used

a) Vacuum tubes b) Transistors c) Microprocessors d) IC’s

Ans: c) Microprocessors

8) Which of the following is a special purpose application software?

a) Word processing software b) Operating System software c) Computer d) Payroll system

Ans: Payroll system

9) The base of Octal Number System is ……….

a) 2 b) 10 c) 16 d) 8

Ans: 8

10) Who is known as the father of the modern computer ?

a) Charles Babbage b) Blaise Pascal c) Herman Hollerith d) Jon Atanasoff

Ans: Charles Babbage

Fill in the blanks :-

1) The first generation computers used magnetic drums for storage.

2) The third generation computers replaced vacuum tubes and transistors

3) Registers are high speed and temporary storage area.

4) Bit is the short form of binary digit.

5) A group of four bits is called Nibble

6) RAM holds data, programs and instructions for computer.

7) A microphone is input device.

8) A Software is set of instructions to perform a specific task.

9) Utility software are used to scan the computers for viruses.

10) The decimal system is composed of Ten digits.

11) Electrical Numerical Integrator and Computer (ENIAC) was the first full electronic general purpose computer.

12) Universal Automatic Computer I (UNIVAC I) was one of the first commercially available computers.

13) An Assembler converts the program written in assembly language into the machine language.

14) Processing takes place in the Control Unit

15) The ALU performs the arithmetic and logical operations.

16) RAM is temporary or volatile

17) ROM stores basic input/output instructions to operate the computer.

18) Electrically Erasable Programmable Read Only memory is an electronic non- volatile storage medium that can be electrically erased and reprogrammed.

19) Data and instructions are given to the computer through its input device.

20) Raw data is processed by the computer to produce Information.

21) Results are obtained from the computer through its output device.

22) 1 MB = 1024 KB.

23) Random Access Memory (RAM) is an example of primary memory.

24) The Octal number system uses the digits from 0 to 7

25) A computer system comprise of both Hardware and Software

26) Software represents the set of program that directs the computer how to work.

State True or False :-

1) Another name for internal memory is primary memory. True

2) A hard disk can store less data than CD. False

3) Software represents to the physical components of a computer. False

4) A projector is an input device. True

5) Interpreter is an utility software. False

6) The first generation computers used transistors. False

7) Atanasoff Berry Computer was the first electronic digital computers. True

8) IBM 604 is an example of second generation computers. True

9) UNIVAC I was one of the first commercially available computers. True

10) ROM is volatile. False

11) A group of eight bits is called nibble. False

12) Computer does not understand any language other than machine language. True

13) Pen drives use flash memory to store data. True

14) The monitor is a soft copy output device. True

15) A compiler translates a program written in machine language into a program written high level languages. False

16) Bit is the smallest unit of data in a computer. True

Short answer questions :-

1) Who is known as the “ father of the modern computer” ?

Ans :- Charles Babbage is known as the “father of the modern computer”

2) What is a computer ?

Ans :- A computer is an electronic device that performs a function based on a given set of instructions. It also works on the principles of Hardwares and softwares.

3) Who invented Jacquard’s loom?

Ans :- Jacquard’s loom was invented by Joseph Jacquard in the year 1801.

4) Give the full form of ENIAC and EDVAC

Ans :- The full forms of the following terms are as :-

i) ENIAC :- Electrical Numerical Integrator and Computer

ii) EDVAC :- Electronic Discrete Variable Automatic Calculator

5) Give two examples of second – generation computers

Ans :- The examples of second- generation computers are IBM 604, UNIVAC 1108.

6) What is AI ?

Ans :- AI is the growing branch in the world of computer technology. This technology helps to perform /make computers thinks like human beings. Ex. Translator- which helps to convert the data from one language to the other.

7) Give two examples of secondary memories

Ans :- Compact Disk (CD) and Hard disk are the examples of secondary memories.

8) What does the CPU do ?

Ans :- CPU performs the work of all calculations like addition, substraction, division and multiplications. It even helps to perform the logical operations like Yes/No type and controls the workings of other units present in the CPU.

9) Why we use secondary memory ?

Ans :- Secondary memory is used to store large amount of data and programs permanently and can be used later whenever required.

10) Give two examples of pointing device ?

Ans :- Mouse and Trackball are the examples of pointing device.

11) Which input device is used to record sound ?

Ans :- Microphone is the input device which is used to record sound.

12) What is the use of barcode reader ?

Ans :- It is used to read the information stored in a barcode.

13) What is system software? Give two examples.

Ans :- System Software is a set of programs designed to operate hardware and control the internal operations of a computer system.

14) What is the role of CU ?

Ans :- The CU controls and coordinates the operations of all the other components of the computer system. It does not process the data but controls the entire processing of data within the computer.

15) What is the function of ALU ?

Ans :- The ALU performs the functions of arithmetic calculations and logical decisions/operations.

16) What do you understand by memory word?

Ans :- Memory is the space which is used to store data and instructions, for immediate desired results.

17) What is the function of a compiler?

Ans :- Compiler converts/translates the programs from the high level languages into the machine readable language.

18) What is the main limitation of a computer?

Ans :- The limitations of a computer are as follows :-

i) It cannot work or make decision on its own, because it don’t have all the abilities of decision making.

ii) It cannot respond/ work on a particular condition unless that condition is already programmed into them.

iii) It’s an electronic machine which means it requires electricity to work. If there’s no electricity it will not work.

iv) When the work is completed you need to save the work otherwise your work will go away.

v) Like laptop, its not portable.

19) Mention three main features of a computer?

Ans :- The three main features of a computer are as follows :-

i) Speed :- Computers works at a very fast speed which means it can carry out millions of instructions per second. The computers speed is measured in nanoseconds (1 nanosecond = 1×10 seconds) and picosecond (1 picosecond = 1×1012 seconds)

ii) Versatility :- Computer can do different types of task more efficiently.

iii) Accuracy :- Computers works at a very fast but without loosing its accuracy. On the basis of correct data or instructions, it provides very accurate results.

20) What is a computer program?

Ans :- Computer program is a set of program/ instructions, which helps to perform various tasks.

21) What are the fundamental components of a computer system?

Ans :- The basic components of a computer are Control Unit (C.U), Arithmetic and Logic Unit (ALU) Memory Unit (M.U), Input/output unit.

22) What is application software?

Ans :- Application Software is a set of programs developed/written by programmers to carry out a specific task/work.

23) Mention various categories of application software?

Ans :- General- Purpose Application software (Packages) and Specific- Purpose Application Software are categories of application software.

24) What do you understand by computer memory?

Ans :- Computer memory is a storage place where the feeded data or instructions into computer is been stored.

25) What is the binary equivalent of hexadecimal 15?

Ans :- The binary equivalent of hexadecimal 15 is 1110

Long answer questions :-

1) Mention four features of a computer system?

Ans :- The main features of a computer are as follows :-

i) Speed :- Computers works at a very fast speed which means it can carry out millions of instructions per second. The computers speed is measured in nanosecond (1 nanosecond = 1×10 seconds) and picosecond (1 picosecond = 1×1012 seconds)

ii) Versatility :- Computer can do different types of task efficiently.

iii) Accuracy :- Computers work at a very high speed without loosing accuracy. It gives correct results, provided the correct data and set of instructions are provided as input.

iv) Tiredness :- As humans get tired of doing the same tasks again and again but

computer does not. It can perform the given tasks again and again without an error.

2) Mention the characteristic features of third- generation computers?

Ans :- The feature of third generation computers are as follows:-

i) The third generation computers were replaced translators with Integrated Circuits (IC’s).

ii) The speed and efficiency of computers, were increased by the chips.

iii) The computers were more powerful, reliable,

iv) These computers were faster in speed and were less expensive.

v) Examples :- IBM 360 series and 370 series.

3) What do you understand by generation of computers? Mention two disadvantages of first generation computers?

Ans :- Generation of computers means new/latest developments in the technology of the computers. Its in relation to the hardware of computers. Latest advanced developments in the technology as compared to the technology of previous generation.

The disadvantages of the first generation computers are as followed:-

Disadvantages

i) Vaccum tubes which were used in first generation computers had a very short span of life.

ii) The first generation computers were very huge in size and consumed a lot of energy where the machines got very hot and which created maintainance problems too.

4) Describe the functioning of CPU

Ans :- CPU looks after and controls the entire working of a computer system just like human brain

which controls the movements or workings of the human body.

5) Draw a block diagram of a computer system

Ans :- The block diagram of a computer system is as followed

6) What are the categories of Printers? Explain.

Ans :- Printers are divided into two categories that is

i) Impact printers :- In this type of printers, there is a link between print head and paper. Inkjet printers are divided into i) line printers ii) character printers.

i) Line printers prints one line of text at a time. Examples of line printers are drum
and chain printers.
ii) Character printer prints one character of a text at a time. Examples of character
printers are Dot- Matrix and letter- quality print

ii) Non- Impact printer :- There is no relation between the printer head and paper. As compared to Impact printers, these type of printers are the most fastest. The main types of Non- Impact printers are inkjet printers, thermal printers, electromagnetic printer and laser printer.

7) What is a bus? Explain three types of buses.

Ans :- The buses are electrical circuitry wires that connects the various components on and transfers data between them on the motherboard. There are three main buses which are :

Data bus :- This bus only carries data from memory to CPU and again back from CPU to memory.

Address bus :- It carries the address from CPU to the memory

Control bus :- It carries instructions between the CPU and other parts of the computer

8) What are the functions of primary storage area?

Ans :- The primary storage area performs the following functions :-

i) It holds input data and instructions

ii) It holds data that is being processed and the processing instructions.

iii) It holds intermediate results of processing.

iv) It holds final results of processing.

9) Explain three types of ROM

Ans :- The three types of ROM are as followed :-

i) PROM:- It stands for Programmable Read Only Memory. This are the blank chips on

which the data and instructions is been written with the help of PROM programmer.

ii) EPROM:- This is a type of memory which can erase the contents/data written on the PROM by exposing with the help of ultraviolet light/rays. EPROM stands for Erasable Programmable Read Only Memory.

iii) EEPROM:- This memory uses an electricity to erase the contents/programs stored on PROM and not with ultraviolet rays/light. EEPROM abbreviation is Electricity Erasable Programmable Read Only Memory.

10) What is the purpose of language processor? Explain the three language processors.

Ans :- Language processors is the system software or a program that is converts the programs written in assembly level languages or high level language into machine readable language program. Assembler, compiler and interpreter are the examples of language processors.

11) Differentiate between data and information.

Ans :- Data :- Data means raw facts and figures or unprocessed data. Data can be anything for example marks obtained by a student in various subjects and his roll number form data.

Information :- Information means processing of unprocessed data or meaningful data. For example Computer prepares result sheets using these data, which is the information.

12) Write short note on fifth generation computers.

Ans :- Fifth generation computers are totally based upon artificial intelligence (AI). AI is the growing branch in the world of computer technology. This technology helps to perform /make computers as per the thinking of human beings.

Ex. Translator- which helps to convert the data from one language to the other. In the parallel processing, many processors are been grouped together to form into one large group processor. A super conductor is a conductor through which electricity can travel without any

resistance/problem resulting faster transfer of information between the parts of a computer. Fifth generation computers are still in development process mode, though there are some applications, such as voice recognition, translator: programs that could translated documents from one language to other.

13) What are the basic differences between four generation of computers?

Ans :- The basic differences between four generation of computers are as follows:

The first generation of computers

i) The first generation of computers started with ENIAC which was then followed by IBM UNIVAC I (Universal Automatic Computers) which was built by Mauchly and Eckert in 1951.
ii) The first generation of computers used vaccum tubes and punched cards.
iii) These generation computers were very big in size
iv) These computers were very slow in processing/performing input/output.
v) As the first generation of computers very big in size they consumed a lot of energy .

The second generation of computers

i) Transistors were introduced in second generation computers.
ii) Due to making use of transistor in this generation computers resulted into reduction in getting machines heated.
iii) Second generation computers were very smaller in size and were very fast as compared to first generation computers.
iv) There was an improvement in the storage capacity.
v) These machines worked with High level languages such as ALGOL and FORTRAN.

The third generation of computers

i) The third generation computers had replaced translators with Integrated Circuits
(IC’s).
ii) This chips increased the speed and efficiency of computers.
iii) The computers were more powerful, reliable,
iv) These computers were faster and less expensive
v) Examples :- IBM 360 series and 370 series.

The fourth generation of computers

i) The microprocessors were launched the fourth-generation computers.
ii) Semi conductor memories were replaced by core memories.
iii) Fourth generation computers became more powerful, compact, reliable, and
affordable.
iv) Faster accessing and processing speeds and increased memory capacity helped in many new operating systems. It gave a rise to Personal Computers (PC’s)
v) Graphical User Interface (GUI) made computers more user friendly.
vi) Examples :- IBM’s Personal Computer (PC) and Apple’s Macintosh.14) Write a short note on Mark- I.

14) Write a short note on Mark- I.

Ans :- The first electromechanical computer was invented by the American Computer Engineer in the year 1943 and it was named as Mark- I. It could multiply two 10-digit number in just 5 seconds. These computers automatically perform on pre-programmed instructi. It was the first operational computer

which was used for general purposes.

15) Explain the two main types of secondary memory.

Ans :- The secondary memory is divided in two types :-

i) Magnetic media :-

a) Floppy Disk b) Hard disk c) Magnetic tapes

ii) Optical Media :-

a) Compact Disk (CD) b) Digital Versatile Disk (DVD) c) Blue ray disk d) Solid State

16) Describe various types of magnetic media ?

Ans :- The various types of magnetic media are :-

i) Floppy disk :- A floppy disk is a flexible and portable disk. It has magnetic coating on it which can store 1.44 MB of data. It was one of the oldest type of storage and nowadays its not used due to its less storage space/capacity.

ii) Hard disk :- Hard disk has set of disks called as platters, each having its own read/write These rotating disks are coated with a magnetic material and are attached within the space between them. Data is recorded on the surface of the disks.

iii) Magnetic tapes :- It can hold large amount of data. It is available in the form of cassettes, reads and cartridges.

17) Mention some areas where computers are used widely.

Ans :- Computers are widely used at some are which are :-

Education :- Computers are used in education for taking online classes, online examinations/ tuitions, e-books etc. A computer can be much helpful in teaching. Teachers use computers to prepare lessons, results, question paper, whereas students use the computers to access internet, do projects works and research works too.

Home :- Computers are used in homes for watching movies, making online bill payments, home tuitions, for playing games, accesing internet, social media, nowadays employees can do their office work from home, internet banking, online shopping etc.

Medical field :- Computers are mostly useful in labs, pharmacies etc. Computers are maintained the records of patients and medicines, maintain hospital bills etc.

Business :- Its used to mainly for sales forecasting, processing the transactions, maintain the employees records, planning purpose, presentation work, and preparing reports etc.

Government :- Its widely used in government departments to improve the quality and efficiency of services. Use to maintain records on the legislative actions, maintaining land records etc.

Banking and finance :- In banks its used to maintain customer’s/account holders information and their conducted transactions People also use computers to access information on stock markets, trade stocks and manage investments.

Communication :- Computers are widely used in communication like sending/recieving emails, chatting, video conferencing, send any documents.

Entertainment :- Computers are used for listening music, watching movies, playing games, creating animaton /cartoon videos, recording sound or music etc.

Reservation :- Computers are used to air flight, railway or bus tickets reservations online. People can book their tickets by sitting in their homes.

Science and Engineering :- It is used by the scientists for the research works, sending and launching artificial satellites.

Military :- Computer is widely used in defense in the matters of missile controlling, performing military operations and planning etc.

18) What are the major operations performed by a computer?

Ans :- A computer basically performs five major operations which are Accepting data or instructions, Processing of data, Storing of data, displaying of output , controlling all the operations in the computer.

19) Differentiate between the following pairs :

i) Input and Output unit

ii) RAM and ROM

iii) Softcopy and hardcopy

iv) Primary memory and secondary memory

v) Impact printer and non- impact printer

vi) Assembler and Compiler

vii) Hardware and software

viii) System software and application software

Ans :- i) The difference between Input unit and Output unit are as followed :-

INPUT UNIT	OUTPUT UNIT
It consist of those input devices that are attached to the computer	It consists of those output devices which are attached to the computer
It helps the user to enter data and commands into the computer system.	It is used to get the output results from the computer.
Converts data into machine understandable form i.e is binary	Output coming from the CPU is in the binary form, it must be converted into human readable form before supplying results to the outside world.
Examples of input devices are : Keyboard, Mouse, Scanner, Microphone etc.	Examples of Output devices are Printer, Monitor, Speaker etc.

ii) The difference between RAM and ROM is as followed :-

RAM	ROM
RAM stands for Random Access Memory	ROM stands for Read Only Memory
The data/instructions stored on RAM memory gets erased when the power supply is been turned off.	The data/instructions stored on ROM memory does not gets erased even the power supply is been turned off
RAM is volatile in nature.	ROM is non- volatile in nature.
It supports reading and writing operations	It does not support write operations. Data only can be read not changed.
Instructions are stored during its operation	Instructions are stored at a time of manufacturing.
Static and Dynamic RAM are it’s types	PROM, EPROM, EEPROM are it’s types

iii) The difference Softcopy and Hardcopy is as followed :-

SOFTCOPY	HARDCOPY
Softcopy means the data or information that is displayed on the monitor screen	Hardcopy means the data or information that is printed on the paper
Softcopy can be only seen but cannot be touched.	Hardcopy can be seen and be touched.
We can edit the data with any changes on softcopy	We cannot edit the data on hardcopy

iv) The difference between Primary memory and Secondary memory is as followed:-

PRIMARY MEMORY	SECONDARY MEMORY
It retains data, instructions and processed output for a short period of time	It retains the data or contents for a long period of time
The contents or data gets lost when there is power failure or when computer is been switched off.	The contents or data does not gets lost even if there is power failure or when computer is been switched off.
Volatile in nature	Non- Volatile in nature.
Primary storage is fast, expensive and less in capacity	Secondary storage is slow, less expensive and large in capacity.
Examples:- RAM (Random Access Memory) and ROM (Read Only Memory)	Hard disk, Compact Disk, Pendrives , Floppy Disks etc

v) The difference between Impact printer and Non- Impact printer is as followed :

IMPACT PRINTER	NON- IMPACT PRINTER
This type of printer makes a physical contact between printer head and paper	This printers does not make any physical contact between printer head and paper.
Slower than Non- Impact printers	Faster than Impact printers
Types are line printers and character printers	Types are inkjet printers, thermal printer, electromagnetic printer and laser printer.

vi) The difference between Assembler and Compiler is as followed :

ASSEMBLER	COMPILER
Assembler converts the programs written in assembly language into machine language	Compiler converts the program written in high level language into machine language
It is an example of language processor	Compiler is also an example of language processor

vii) The difference between Hardware and Software is as followed :-

HARDWARE	SOFTWARE
Hardware is the physical parts of a computer system	Software is a set of programs designed to perform a specific task
Hardware can be seen and touched	Software cannot be seen and touched.
Hardware cannot work on its own, and hence it requires software to instruct what to do.	Hardware is required for a software to work on.
Ex. Input devices, Output devices, CPU, memory devices etc.	Ex. System software and application software, utility software etc.

viii) The difference between System software and Application software is as followed:-

SYSTEM SOFTWARE	APPLICATION SOFTWARE
System software is a software which controls and manages the resources and workings of entire computer system	Application software is a software designed for a specific purpose.
System software provides specific functionalities like booting of computers properly, managing memory, managing of hardwares	Application software provides application specific functionalities to a user.
For ex:- Windows operating system, Unix and Linux etc	For ex:- MS office suite, Tally, Adobe Photoshop etc

SEBA Class 9 Computer Science Chapter 1: Basics Of Computer System All Questions & Answers