Computer Science & Programming : April 2021

Chapter-4

Secondary Storage Media

1. Fill in the blanks:

a. Magnetic tape is a plastic tape usually half an inch wide, coated on one side with iron oxide which can be magnetized.

b. Magnetic tape is a sequential storage device.

c. Examples of optical disks are CD ROM and DVD.

d. A magnetized spot represents 1 (bit) and the absence of a magnetized spot represents 0 (bit).

e. Flash memory is non volatile memory.

2. State whether the following statements are True or False:

a. The secondary storage device that follows the sequential mode of access is a magnetic disk. FALSE

b. Optical disk is made by plastic material. FALSE

c. The new high-performance hard disks rotate at 720 rpm - 1000 rpm. FALSE

d. The CD-ROM is a kind of magnetic disk. FALSE

e. The word bits is a contraction of two words binary and digits. TRUE

3. Give the full forms of the following abbreviations:

CD-ROM = Compact Disk Read Only Memory

DVD = Digital Video / Versatile Disk

MB = Megabyte

GB = Gigabyte

BITS = Binary Digits

CD-RW = Compact Disk Rewritable

WORM = Written Once and Read Many times

4. Match the following:

GROUP A	GROUP B
BIT	The smallest unit of information on a machine and a single bit can hold only one of two values: 0 and 1
Nibble	A collection of four bits
Byte	A location in computer memory consisting of eight adjacent bits
Megabyte	The standard unit of measurement for RAM which is equal to 1024 kilobytes
Gigabyte	The standard unit of measurement for hard disks which is equal to 1024 megabytes

5. Name the technical terms for each of the following statements:

a. A non volatile storage medium that can store all the data and instructions even after the computer is turned off.
➭ Secondary Storage Media / Memory

b. A plastic tape usually half -an - inch wide, coated on one side with iron oxide, which can be magnetized.
➭ Magnetic Tape

c. Disk storage system consists of a rotating disk.
➭ Hard Disk

d. A storage medium from which data is read and to which it is written by lasers.
➭ Optical Disk

e. A location in computer memory consisting of eight adjacent bits.
➭ Byte

6. Choose the best alternatives for each of the following:

a. An example of sequential storage media is Magnetic Tape.

b. Storage cost of the optical disk is Very Low.

c. The hard disk is Secondary Memory.

d. A storage media that stores data permanently is called Non - Volatile memory.

7. Answer the following questions:

a. What is secondary storage? State at least two advantages of it.

ANSWER: A non volatile type of memory which is cheaper and slower and have huge storage capacity is called Secondary storage.

Two advantages of secondary memory is as follows:

· Non Volatile: It is non volatile in nature. It does not lose its contents even when the power supply to the computer is terminated. It does not require a continuous power supply as the primary memory does.

· Capacity: Secondary storage media can store a large amount of data and programs in sets of disks that take up less space.

b. What is a magnetic tape? Why is it called sequential access media?

ANSWER:

A secondary storage medium which is used to store data, information for future reference which is used in mini , mainframe or super computers is called magnetic tape.

Magnetic tape is also called sequential access media or device because it is in a sequential nature. It stores and accesses the data and information sequentially.

c. What are the advantages and disadvantages of magnetic tape?

ANSWER:

Advantages of Magnetic Tapes:

· Magnetic tapes are easily transportable because they are light and compact in size.

· They are the cheapest mode of offline data storage.

· Magnetic Tapes are very durable. They can be erased as well as reused.

Disadvantages of Magnetic Tapes:

· Data transmission in magnetic tapes is slow as compared to magnetic disks.

· Magnetic tapes should be kept in a dust free environment and away from chemicals as they can cause tape reading errors.

· Magnetic tape is in sequential nature.

d. What is flash memory? Why is it popular?

ANSWER:

A non volatile memory which is similar to EEPROM and can store a large amount of data is called flash memory.

Flash memory is more popular because of its small size and portability with huge storage capacity and can be used in wide range of consumer devices, including USB flash drives, mobile phones, digital cameras , tablet computers, PC cards in notebook computers.

e. List any three advantages and disadvantages of magnetic disks as a secondary storage media.

ANSWER:

Three advantages of magnetic disks are as follows:

It is most widely used and popular storage mediums for direct access secondary storage.
The data in magnetic disk can be erased and reused.
The disk is covered within a protective case or cartridge to shield it from the dust and other external interference.

Three Disadvantages of magnetic disks are as follows:

Data can be altered by magnetic fields, dust, mechanical problems
Gradually lose their charge over time - data lost
Hard disks eventually fail which stops the computer from working.
Regular crashes can damage the surface of the disk, leading to loss of data in that sector.

f. What is an optical disk? Which technology is used to read/write on to optical disk?

ANSWER:

A storage system consists of a rotating disk, which is coated with a thin metal or some other highly reflective material is called optical disk.

Laser beam technology is used to read/write on to optical disk.

g. What is a CD-ROM?

ANSWER:

An optical disk where data is written once and read many times (WORM) which is a shiny, silver colour metal disk of 12 cm diameter is called CD-ROM. It is made up of a resin , such as polycarbonate material.

h. List any two advantages and disadvantages of optical disks as a secondary storage media.

ANSWER:

Two advantages of optical disks are as follows:

· An optical disk is tougher than tapes of floppy disks. It is physically harder to break, melt or wrap.

· The cost of a optical disk is very low. Because of their low cost and enormous storage capacity, they are used widely.

Two Disadvantages of optical disks are as follows:

· The data access speed of an optical disk is slower than in the speed of a magnetic disk.

· Reading writing procedures are more difficult in optical disks than magnetic disks.

i. Differentiate between sequential access and random access media with one example each.

ANSWER:

Sequential Access Media	Random Access Media
1. The media in which we access the data and information sequentially i.e. one after another is called Sequential Access Media.	1. The media in which we access the data and information randomly i.e. from start , end or from middle is called Random Access Media.
2. Examples: Magnetic Tape	2. Examples: Hard Disk

j. What is a byte? How much bytes are there in 3MB?

ANSWER:

A location in computer memory consisting of eight adjacent bits is called a byte.

1 MB = 1024 KB = 1024 * 1024 bytes = 1048576 bytes

3 MB = 3 * 1048576 = 3145728 bytes

k. What is a nibble? How many nibbles are there in 8 bytes?

ANSWER:

A collection of four bits is called a nibble.

Here,

1 Byte = 8 bits

8 Bytes = 8 x 8 = 64 Bits

Also, 4 Bits = 1 Nibble

1 Bit = 14 Nibble

64 Bits = 14x 64 = 16 Nibble

Hence, 8 Bytes = 16 Nibble. Answer

***** END OF CHAPTER - 4 *****

Ans of (IX) Chapter 6

1. Fill in the blanks:

a. Software instructs the hardware what to display on the user’s screen.

b. System software provides a platform for other programs to run onto them.

c. Programming languages are used in the development of software.

d. An interpreter translates a statement into a program and executes the statement immediately.

e. System utility software performs tasks related to the maintenance of the computer system.

f. A programming language is a primary interface of a programmer with a computer.

g. Language translators translate the instructions prepared by programmers in a programming language.

h. Package software performs specific tasks for the verities of users.

2. State whether the following statements are true or false.

. Software is classified into two categories. True

a. System software supports the execution of other application software. True

b. An interpreter translates the whole program at a time. False

c. The compiler translates one instruction at a time. False

d. Every computer needs operating system software. True

e. Compilers and interpreters are used to translate the high level language programs to the machine code. True

f. The assembly language program doesn’t need a language translator. False

g. Application software is designed to do a specific job for the user. True

3. Select the best answer for the following:

. A computer system is incomplete without:

i.Joystick

ii.Multimedia

iii.Software

iv.Mouse

a. A software is collection of:

.Data

i.Programs

ii.Instructions

iii.Errors

b. A language translator that translates instructions of high level languages to the machine code line by line:

.Compiler

i.Interpreter

ii.Assembler

iii.Language Convert

c. An example of tailored software is:

.MS Word

i.QBASIC

ii.Result Processing Software

iii.MS Windows

d. The software that looks the entire source code and converts to the machine code:

.Assembler

i.Interpreter

ii.Compiler

iii.None

4. Write the technical terms of the following:

. Instructs the hardware what to display on the user's screen

Ans: Software

b. The software which is responsible for performing basic task such as input from the keyboard, sending output to the display screen, keeping tracks of files and directories on the disk
Ans: Operating System Software

c. Translates the source code of high level language into the object code
Ans: Language Translator

d. The software which is used to support, improve , expand and secure the existing programs and data in the computer system
Ans: Utility Software

e. Translates an assembly program into machine level program

Ans: Assembler

5. Answer the following questions:

a. What is software? Why is it necessary on the computer?

ANSWER:

A set of program written in a programming language for a computer to perform a particular task is called Software.

Software is necessary for computer because it instructs the hardware what to do, how to do it and when to do it . Without software computer can not run at all.

b. What is system software? What is its function?

ANSWER:

The software that contributes to the control and performance of the computer system and permits the user to use the system more conveniently is called system software.

The main function of the system software is responsible for the management and accurate functioning of the computer system. It also provides a platform for other programs to run onto them.

c. What is operating system software? Define its role.

ANSWER:

An organized collection of programs that controls the overall operation of the computer system is called operating system.

Examples of operating systems are: MS-DOS, Windows XP, Windows 7, Windows Vista, Linux, Mac OS, and UNIX etc.

Operating system plays a role of interface between the user and computer hardware.

d. What is meant by language translator? Name different types of language translators.

ANSWER:

The system software which transform the instructions prepared by a programmer's in a programming language into a form of 0s and 1s is called language translator.

There are three types of language translator:

· Assembler

· Interpreter

· Compiler

e. What is application software? Why is it designed?

ANSWER:

The program which is designed to do only specific task is called application software. The application software made for one purpose can’t do other task. For example: - accounting of your college can not prepare the result sheet of your college. Application system works on system software.

Application software is designed because tasks of computer will be different for the various user.

f. Differentiate between packaged software and customized software.

ANSWER:

Packaged Software	Customized Software
1. The software which is mainly designed by software companies to generalize the tasks is called Packaged Software.	1. The software which is designed by software companies for specific task is called Customized software.
2. Examples: Microsoft Word, Microsoft Powerpoint etc.	2. Examples: SEE result system of Nepal, Electricity Billing system of Nepal etc.

g. What is interpreter?

ANSWER:

Language translator, which analyses and executes the source code written in high level language in a line by line manner, without looking at entire program is called interpreter.

h. What is utility software? Give an example.

ANSWER:

The collection of programs which perform day to day tasks related to the maintenance of the computer system is called utility software. This is used to support, improve, expand and secure the existing programs and data in the computer system.

Some Examples of Utility Software:

· Virus Scanning Software

· Backup Software

· Scan Disk

· Disk Defragmenter Software etc

i. Differentiate between compiler and interpreter.

ANSWER:

Compiler	Interpreter
1. A compiler is a program which translates a high level program to machine language at once.	1. Interpreter is a program which translates a statement of high level language program to machine language.
2. Program execution time is more before producing executable program.	2. It can execute immediately.
3. It occupies larger part of memory.	3. It occupies less memory space because it is smaller program in comparison to compiler.
4. It is faster because it runs executable programs.	4. It is slower because it repeats the process from the beginning.
5. Examples: C, C++,FORTRAN etc.	5. Examples: BASIC, LISP etc.

j. Differentiate between source program and object program.

ANSWER:

Source Program	Object Program
1. The program written by a user using a programming language is called source program.	1. The translated program which is in binary form is called object program.
2. It will be either in assembly or high level language.	2. It will be machine language i.e. in 0 and 1 form.

k. Why do computers need utility software?

ANSWER:

Computers need utility software because for day to day tasks related to the maintenance of the computer system is done by utility software. Without utility software we can not perform any type of tasks in a computer system.

l. Why is tailored software demanded by the user or an organization?

ANSWER:

Each user or organization have different types of task for their day to day work. As tasks is different from each other , software is also need to be different. This problem is well addressed by the tailored software. That’s why, tailored software is demanded by the user or organization.

m. What is programming language?

ANSWER:

A vocabulary and set of grammatical rules for instructing a computer to perform specific task is called programming language.

n. What is open source software?

ANSWER:

The practice of making the source code for a software product freely available , at no cost, to the interested users and developers , even though they were not involved in creating the original product is called open source software.

-----The End----

Ans of (IX) Ch-7 Operating System

Chapter - 7 Operating System

1. Answer the following questions:

a. What is an operating system?

ANSWER:

A collection of the system programs that together control and coordinate the operation of a computer system is called operating system. It acts as an intermediate between a user and the computer hardware.

b. What are the functions of an operating system? Explain in brief.

ANSWER:

The functions of an operating system are as follows:

1. Memory Management: As a memory manager, the operating system takes care of the allocation and deallocation of the memory space to the various programs.

2. File Management: As a file manager, the operating system takes care of the file- related activities such as organization, storing, retrieval, sharing , protection of files etc.

3. Process Management: As a process manager, the operating system takes care of the creation and deletion of the processing schedule of various systems resources and makes communication among processing.

4. Command Interpretation: As a command interpretation manager, the operating system takes care of interpreting user, commands, and directing the system resources to hand the request.

5. Security: As a security manager, the operating system protects the resources and information of the computer system against destruction and unauthorized access.

6. User Interface: The operating system provides the interface between the user and the hardware. The user interface is the layer that actually interacts with the computer operator. The interface consists of a set of commands or menus through which a user communicates with a program.

c. What is windows operating system?

ANSWER:

One of the popular operating system software programs for PCs(Personal Computer) developed by Microsoft Company, USA based on GUI( Graphical User Interface) is called windows operating system.

d. What is the importance of windows operating system?

ANSWER:

The importance of windows operating system are as follows:-

1. It is based on GUI. Every item is in the graphical form.

2. It makes easy to use computer

3. It is easier to manage the computer resources. (Set Up, administrator, support)

4. It helps to run the multiple programs at a time.

5. It allows a long file name.

6. It produces highly reliable communication in the internet.

e. How long file name is accepted by windows?

ANSWER:

Windows can accept 255 characters for the file name.

f. What is meant by GUI?

ANSWER:

The operating system in which the user can supply the commands and instructions from the menu option using a pointing device called mouse is known as GUI.

g. What is desktop?

ANSWER:

The overall working area while you are in windows is called desktop.

h. What is an icon?

ANSWER:

A graphical image with a name under it which helps the user to recognize the software is called icon.

i. What is the use of icons in windows?

ANSWER:

The icon is used to represent the folders, files, documents and programs.

j. What is the task bar?

ANSWER:

A graphical toolbar in windows which is located at the bottom of your screen when you start windows for the first time is called taskbar.

k. What is the start button?

ANSWER:

The main component of the operating system placed in the taskbar whose function is to open the main menu of the windows and control the windows is called start button.

l. Differentiate between application windows and document windows of a program?

ANSWER:

Application Windows	Document Windows
1. The windows which displays the executable windows program in GUI platform is called Application windows.	1.The window that comes inside an application window is called Document window.
2. These types of windows can be resized and moved within the desktop.	2. These types of windows can be moved just within an application window.

m. What is the function of shortcut?

ANSWER:

The function of shortcut is to link to a document , program, folder or web page etc. that allows the user to find a file or resource located in a different folder from the place where the shortcut is placed.

n. What is the folder?

ANSWER:

A container for programs and files in windows operating system environment is called folder.

o. What is the recycle bin?

ANSWER:

The special folder of the hard disk represented by an icon with the recycling logo is called recycle bin.

p. What is the function of the recycle bin?

ANSWER:

The function of the recycle bin is that it allows user to browse deleted files, undelete those that were deleted by mistake , or delete them permanently from the computer.

q. What is a clipboard? What is its role.

ANSWER:

The temporary location of the windows environment operating system is called clipboard.Its role is that it allows to store texts, graphics, files and other items temporarily after using the ‘CUT’ command to move and copy the items.

2. Write T for true and F for false statement.

a. Operating system controls only the application software of the computer. FALSE

b. Moving refers to deleting an item from its previous location. TRUE

c. Copying procedure doesn’t leave the original information. FALSE

d. Items deleted from a disk go to the recycle bin. TRUE

e. Shift+Del key are used to delete items without sending to the recycle bin. TRUE

f. There are three scroll bars in the windows. FALSE

3. Write short notes on:

a. Single User Operating System

An operating system that allows a single user to perform one or more tasks at a time is called single user operating system. By means, the single user operating system is classified into two categories:-

(i). Single-User/single-Tasking operating system

(ii). Single-User/Multi-User-tasking operating system.

b. Multi-User Operating System

Some operating systems allows a computer to support several user at a time. In the Multi-User operating system, each user works at a workstations connected to the main computer called server. The computer can be macro, mini or mainframe. The types of OS(Operating System) of the computer assigns each user a portion of RAM and divides the computer’s time among the various users. The computer does small amount of work for one user, then does a small amount of work for the next user and so on. Since, the computer operates so quickly, each user feels that the computer is working for him alone. Multi-Users OS may have hundreds of users at the same time. Unix and Linux are examples of multi-users OS.
***** END OF CHAPTER - 7 *****

Computer Science & Programming

Monday, 19 April 2021

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Define information clearly.

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Define the term data

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Specification Grid Including sample questions

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Class IX Solution

MCQ Question Bank Microsoft PowerPoint