Class 9 Computer Science Chapter 2 Operating System and Its Importance

Class 9 Computer Science Chapter 2 Operating System and Its Importance Question Answer, SEBA Class 9 Computer Science Solutions, NCERT Class 9 Computer Science Chapter 2 Operating System and Its Importance to each chapter is provided in the list so that you can easily browse throughout different chapters SCERT Class 9 Computer Science Chapter 2 Operating System and Its Importance and select needs one.

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Class 9 Computer Science Chapter 2 Operating System and Its Importance

Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. NCERT Solution of Class 9 Computer Science Chapter 2 Operating System and Its Importance is part of AHSEC All Subject Solutions. Here we have given Class 9 Computer Science Chapter 2 Operating System and Its Importance Notes for All Subjects, You can practice these here in Class 9 Computer Science.

Operating System and Its Importance

Chapter – 2


Important Terms (Basic Concepts)

● Operating system: An operating system is a system software that acts as an interface between the user and the hardware resources. It provides a variety of services to the computer.

● Booting: Booting is basically the process of starting the computer.

● Multiuser: A Multiuser operating system is a computer operating system which allows multiple users to access the single system with one operating system on it.

● Multitasking: The Os handles multitasking in the way that it can handle multiple operations/executes multiple programs at a time.

● Directory: A directory is a file system cataloging structure which contains references to other computers.

● Root directory: The top-most directory in such a file system, which does not have a parent of its own, is called the root directory.



1. Choose the correct option.

(a) Which of the following is an operating system?

(1) Windows

(2) Linus 

(3) Unix 

(4) All of these 

Ans: (4) All of these.

(b) Which Opreting System is developed by CDAC, Chennai?

(1) Windows

(2) BOSS

(3) Unix

(4) None of these

Ans: (2) BOSS.

(c) Which OS has fixed deadline?

(1) Distributed 

(2) Real – time 

(3) Interactive

(4) Batch Processing

Ans: (2) Real-time.

(d) Name a multiuser Operating system.

(1) MS-DOS

(2) BOSS

(3) Unix

(4) None of these

Ans: (3) Unix.

(e) Neme a version of macOS.

(1) Mojave  

(2) High Sierra

(3) Sierra

(4) All of these

Ans: (4) All of these.

(f) In which year was Windows OS released?

(1) 1980

(2) 1985 

(3) 1983

(4) 1987

Ans: (2) 1985 .

2. Fill in the blanks.

(a) _____ is the founder of Microsoft Corporation.

Ans: Bill Gates.

(b) An operating system is a program which acts as an _______ between a user and the hardware.

Ans: interface.

(c) The operating system decides which job should use the _____ and for how long .

Ans: processor.

(d) A computer system works with _______.

Ans: information.

(e) Windows is an example of _______ operating system.

Ans: proprietary.

(f) Unix was originally developed in _______ by a group of AT&T employees.

Ans: 1969. 

3. State true or false.

(a) Microsoft Windows has 15 versions since its first release in 1985.


(b) Linux is different from proprietary software like Windows, which can be modified by the company that owns it.

Ans: TRUE.

(c) iOS is Apple’s mobile operating system.


(d) The latest version of Android is Unnati.


(e) Windows come pre-loaded on most new PCs.

Ans: TRUE.

(f) macOS is Apple’s mobile operating system.

Ans: TRUE.


Short answer questions

1. What is an Operating system?

Ans. An operating system (OS) is a program which acts as an interface between a user and the hardware i.e., all computer resources and controls all components of the computer system. Its main goal is to make the computer system convenient to use.

2. Mention the names of any two commonly used operating system.

Ans.The commonly used operating system are Linux Operating system, Windows Operating system, iOS Operating system etc.

3. When was the first version of Apple iOS released?

Ans. The first version of Apple iOS was released on 29 July 2007.

4. What do you mean by multitasking?

Ans. Multitasking, in an operating system, is allowing a user to perform more than one computer task (such as the operation of an application program) at a time.

5. What is real-time operating system?

Ans. In real-time OS, the jobs have fixed deadlines and the jobs have to be completed within their deadlines. The system performance is measured by its ability to complete it’s jobs within the specified deadlines. Examples are LynxOS, Windows CE etc.

6. What is time sharing and distributive operating system?

Ans. Time Sharing OS – A time sharing operating system allows many users to share the computer resources simultaneously. In other words, time sharing refers to the allocation of computer resources in Time slots to several programs simultaneously.

Distributive OS – Distributive operating system is designed to share its work load over multiple servers (mostly at multiple locations). It shares data and resources among its multiple servers to get maximum efficiency. Examples are Unix, Linux etc.

Long answer questions

1. Explain any two functions of an Operating system.

Ans. Important functions of an operating system are : 

Processor Management: In a multi programming environment, the OS decides the order in which processes have access to the processor, and how much processing time each process has.

Memory Management: An Operating system keeps tracks of primary memory, i.e., what part of it are in use by whom, what part are not in use. It decides which process will get memory when and how much. It allocates the memory when a process requests it to do so and de- allocates the memory when a process no longer needs it or has been terminated.

Device Management: An Operating system manages device communication via their respective devices. It keeps tracks of all devices and decides which process gets the device when and for how much time. It allocates and de-allocates the device in the efficient way.

Information Management: A computer system works with ‘information’. It stores information, processes information and provides information etc. Thus, managing this information is also an important task performed by an operating system.

File Management: The operating system manages the files, folders and directory systems on a computer.

Security: The operating system uses password protection to protect user data and similar other techniques. it also prevents unauthorized access to programs and user data.

2. Explain any two- operating system used in mobile phones.

Ans. A mobile operating system is an operating system that helps to run other application software on mobile devices. The following are the popular platforms of the Mobile OS : 

Android OS: The Android mobile operating system is Google’s open and free software stack that includes an operating system, middleware and also key applications for use on mobile devices, including smartphones. Updates for the open source Android mobile operating system have been developed under ”dessert-inspired” version names (Cupcake, Donut, Eclair, Gingerbread, Honeycomb, Ice Cream Sandwich, Naugat, Oreo, pie) with each new version arriving in alphabetical order with new enhancements and improvements.

IOS: iOS stands for the iPhone Opreting System. It is Apple’s mobile operating system developed and distributed by Apple Inc. It is designed to run on Apple devices like iPhone, iPad, iPod, etc The first version of Apple iOS was released on 29 July 2007.

3. Write a short note on Windows operating system.

Ans. Windows is a graphical operating system developed by Microsoft.It allows users to view and store files, run the software, play games, watch videos, and provides a way to connect to the internet. It was released for both home computing and professional works. Microsoft introduced the first version as 1.0.

4. Write a note on the Operating systems created by Apple.

Ans. Mac OS, operating system (OS) developed by the American computer company Apple Inc. The OS was introduced in 1984 to run the company’s Macintosh line of personal computers ( pCs).

5. What is BOSS? 

Ans. Bharat Operating system solution (BOSS GNU/Linux) is an Indian Linux distribution derived from Debian. It is developed by Centre for Development of Advanced Computing (C-DAC) in order for enhancing and gain benefit from the usage of Free and Open Source Software throughout India.

6. Write a short note on Bill Gates.

Ans. William Henry Gates III (born October 28,1955) popularly known as Bill Gates is an American business magnate, software developer, and philanthropist. He is the founder of Microsoft Corporation. During his career at Microsoft, Gates held the position of chairman, chief executive officer (CEO), president and chief software architect. Microsoft Windows Operating system has seen 10 major versions since its release in November 1985. Over 35 years later, Windows looks very different but somehow familiar with elements that have survived the test of time and most recently – a shift from keyboard and mouse to touchscreens.

7. What is Interactive Operating system? Where is it used?

Ans. An interactive operating system is one that allows the user to directly interact with the operating system while one or more programs are running. There will be an user interface in place to allow this to happen. It could be a command line style of interface or could be a graphical interface.

Interactive operating systems are computer systems characterized by significant amounts of interaction between humans and the computer.Most users have grown up using Macintosh or Windows computer operating systems, which are prime examples of graphical interactive systems. Games and simulations are interactive systems.

8. What are the two important features that must be taken care while maintaining a directory?

Ans. The two important features that must be taken care while maintaining a directory are given below: 

(i) A user must have freedom of giving the desired name to the file, without taking into consideration that same file names are used by other users on the system.

(ii) A user must be able to share the files he creates and he must also be able to access the files, created by other users.


1. What is an operating system?

Ans. An operating system is a system software that acts as an interface between the user and the hardware resources. It provides a variety of services to the computer.

2. Which is the first program that loads in memory?

Ans. Operating system is the first program that loads in computer’s main memory, when a computer is switched on.

3. What do you mean by buffering?

Ans. Buffering is a technique of storing data in memory area (buffer).

4. Who released the first Android OS ‘Astro’ ?

Ans. The First Android OS’Astro’was released by Google on September 20th, 2008.

5. Which OS operates on Smartphones?

Ans. Mobile OS is the type of OS, that operates on Smartphones, Tablet, PDAs or other Digital Mobile devices. Several types of mobile operating systems are available in market are : 

Android, BlackBerry, iOS, Windows etc.

6. What do you mean by Linux?

Ans. Linux is an open source operating system, means anyone can download it and use it without any fees. It is similar to Unix in its working and difficult to understand. It is an OS that controls your computer system.

7. Define GUI.

Ans. GUI stands for Graphical User In GUI, user interacts with applications by making user of graphics. More than one task can simultaneously. e.g. Windows.

8. What is multi-tasking OS?

Ans. The OS that allows the execution of multiple tasks at one time is known as multi-tasking. OS. In this type of OS, several applications may be simultaneously loaded and used in the memory. While, the processor handles only one application at a particular time. Unix, windows 2000/XP/NT/Vista etc.

9. What is the difference between 32-BIT and 64-BIT Operating system?

Ans. A 32-bit system can access 232 memory addresses, i.e 4 GB of RAM or physical memory ideally, it can acces more than 4 GB of RAM also. A 64-bit system can access 264 memory addresses. i.e actually 18-Quintillion bytes of RAM.

10. What is directories?

Ans. Group of files combined is known as directory. A directory contains all information about file, its attributes.

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