# Current Affairs 4th Class

#### Area and Perimetre

Area and Perimetre   Introduction In the previous chapter we have studied about the shape and size of some geometrical figures. In this chapter we will study about area and perimetre of some close geometrical figures,   Area Area is referred as the surface occupied by the geometrical shapes   Area of a Triangle Area of a triangle Where base is one side of a triangle and height is the length of altitude drawn from opposite vertex on the given base, Area of the triangle Where BC is the base and AD is the height,
•            Example
Find the area of the triangle whose base is 5 cm and height is 8 cm. Solution: Area of the triangle   Area of a Rectangle Area of a rectangle Area of the rectangle
•            Example
Find the area of the rectangle whose length is 9 cm and width is 7 cm, Solution: Area of the rectangle = 9 cm x 7 cm = 63 cm2   Area of a Square Area of a square Area of the square
•            Example
Find the area of the square whose length of one side is 6 cm. Solution: Area of the square   Area of a circle Area of the circle Where more...

#### Data Handling

Data Handling   Introduction In our day to day life, time to time we come across graphs while reading or watching news, etc. The graphs are prepared with the help of data. Data is collected through survey or other means. The data can be arranged in a specific order as per our need by using table. In this chapter we will study about some of the graphical representation of data, how to make the graphs and how to extract information?s contained by the graphs.   Data The information which is collected in the form of numerals is called data.   Raw Data The initial data that the observer collects himself is called raw data.   Grouped Data To extract the information?s contained in the data easily, the data is arranged in ascending or descending order using tables.   Graphical Representation of Data Data can be represented graphically by using Pictographs, Bargraphs, Pie charts etc. In this chapter we will learn about Pictographs and Bargraphs.   Pictograph When the data is represented on the graph with the help of pictures the graph is known as Pictograph.
•            Example:
Number of sixes hit by Sehwag against different team in a tournament has been shown in the following pictograph.
Australia
Pakistan
South Africa
New Zealand more...

#### Computer and Its Peripherals

Computer and Its Peripherals   Introduction Computer peripheral is defined as the device that is connected with the host computer. A computer peripheral only useful when it is able to communicate with external or internal environment. When you work with the computer you input your data and instructions. Through some devices to the computer. These devices are called input devices. Similarly, computer after processing given output through other devices called output devices.   Input/ Output devices are known as peripherals since they surround the CPU and memory of a computer system. Computer can also be defined in terms of functions it can perform. A computer can.             i.      Accept data        ii.      Store data       iii.      Process data as desired data       iv.      Retrieve the stored data and when required and        v.      Print the result in desired format.   Some of commonly used input/ output devices are listed in the following table:
Input Devices Output Devices Both Input/ Output Devices
Keyboard more...

#### Computer Memories and Its Types

Computer Memories and Its Types   Introduction A memory is just like a human brain. It is us to store data and instructions. Computer memory is the storage space in computer where data is to processed and instructions required for processing are stored. The memory is divided into large number of small parts called cells. Each location or cell has a unique address which varies from zero to memory size minus one. For example if computer has 64k words, then this memory unit has 64*1024=65536. The address of these locations varies from 0 to 65535.   Units to measure memory are given in the following table:             Bit = 0 or 1 (Binary Digit)             Nibble = 4 Bits             1 Byte (b) = 8 Bits             1 Kilobyte (KB) = 1024 B             1 Megabyte (MB) = 1024 KB             1 Gigabyte (GB) = 1024 MB             1 Terabyte (TB) = 1024 GB             1 Petabyte (PB) = 1024 TB   Memory is primarily of two types:         1)     Primary Memory     2)     Secondary Memory   Primary Memory: Primary Memory holds only those data and instructions on which computer is currently working. It has limited capacity and data is lost when power is switched off.   Characteristics of main memory:
• These are semi-conductor memories.
• It is known as main memory.
• Usually called volatile memory.
• Data is lost in case power is switched off.
• Faster than secondary memories.
• A computer cannot run without primary memory.
RAM (Random Access Memory) more...

#### Characteristics of Memory Devices

Characteristics of Memory Devices   Introduction You may have used the computer to store games, music, files and pictures in it. These files get stored in the memory devices. A memory is just like a human brain. It is used to store data and instruction. A memory system is a hierarchy of storage devices with different capacities, costs and access times. When a user issue commands to start application software, such as word processing, the operating software, such as word processing, the operating system locates the program in the storage and loads it into memory. In this we will learn about some characteristics of memory device.   Storage Capacity Like human beings need to memorize things, which can be retained and recalled on need computer also need to store data and instruction for future use. A computer deals with different types of memories. Two major types of computer memories are (1) Primary (main) Memory (2) Secondary (auxiliary) Memory.   Storage capacity term refers to the size of memory. Primary memory is generally costly and has capacity limitation, further it cannot retain data for longer period of time. However, we need to store data and instructions for long time so that they can be used later. For this purpose, Secondary storage is used. The Secondary storage stores large amount of data, instructions and information permanently. The popular secondary devices are hard disk, compact disk (Cd\s), digital versatile disks (DVDs), and pen drives.   Secondary memory is not directly accessible to processor of a computer but requires use of computer's input/output channels. Such memory is usually slower than primary memory but it always has higher storage capacity. Data remains unchanged even after switching off the computer. Secondary memory/storage is also known as auxiliary memory storage.   Units of measure memory are given in the following table:
Bit          more...

#### Software Classification

Software Classification   Introduction When you play games on a CD, you can see and touch the CD but can't the games. In this case, the CD is the hardware and games make up the software. Software is commonly known as programs or app, consists of all the instructions that tell the hardware how to perform a task. Computer software is a computer tool that will help computer users to interact with the machine or the hardware in a computer. Without computer software's you will not be able to make the computer run and thus working on computer may not be easy as it is today. Software programs are normally written and compiled for certain hardware platforms. It is very important that the software is compatible with all the components of the computer.       Bordly the entire computer software system can be categorized as system and application software.   System Software System software is the basic requirement of any computer, as it run the computer hardware and computer system itself. It is also responsible for controlling, integrating and computer system and also run application software, such as web browser, media players etc. It also includes number of applications, such as utilities, operating systems, compilers and debuggers. The main function of this software is to operate the computer hardware and provide a platform for running application software.   Operating System The operating system is just like a secretary who does all the work tor the boss. An operating system is also abbreviated as OS. OS is a software program that enables the computer hardware to communicate and operate with the computer software.   Following are a few common services provided by an operating
• Program execution
• I/O operations
• File system manipulation
• Communication
• Error detection
• Protection
• Resource allocation
Similarly when you ask the operating system to do things such as:
• Copy a .dat
• Delete myfile .dat
All these operations are more...

#### A Brief About Computer Languages

A Brief About Computer Languages   Introduction You communicate with your family and friends by speaking languages like English, Hindi or your mother tongue. A computer can understand only binary language because it operates upon electricity Electric signals have two states ? ON or OFF (or 10 be very specific ? high voltage or low voltage,) If we denote ON by 1 and OFF by 0,, it becomes a binary language i.e. a language with just two symbols. For the computer 1 means ?Yes there is power? and 0 means ?No, there is no power?. Thus, it can understand only electric signals and the computer can understand binary language as n symbolizes electric signal.   A computer follows the instructions given by the programmer to perform a specific job, such as add, read a file, etc. This sequence of instructions is known as a program. A program written for a computer is known as software. The computer understands only the binary language which is also known as Machine Language or Low Level Language.  Earlier programs were written only in machine language in which, each instruction was in the form of long strings of 1?s and 0?s. These programs were understood by the computer but not easily understood by human beings. Therefore, the computer remained a mystery to the common man till High Level Languages were developed. The 'journey of the computer software from the machine language to high level languages is an interesting one which we will discuss in some detail in this chapter.   Low Level Programming Language People use languages like English, French, and Japanese. Computer use languages like machine language and assembly language. They are CPU specific, making direct use of internal registers. Mnemonics are use as programming code such as MOV or ADD. In computer science, Low level languages allow for close control of the CPLI, for example many device drivers are coded in assembly language. They can be very efficient. Well optimised code written in a low level language can be made to run very quickly compared to other programming paradigms. Low-level programming languages are sometimes divided into two categories:   First Generation Language 1 GLs (Machine Language) When the human being first started programming the computer, he used machine language or binary language. A machine language is a collection of binary digits more...

#### Fundamentals of Windows 10

Fundamentals of Windows 10   Introduction Windows 10 is the latest OS version from Microsoft Officially it was released in July and was initially offered free of charge to legitimate users of' Windows 7 and Windows 8. The new version combines features from these two previous versions to suit the users m, a better way for both Desktop/Laptop computers as well as mobile device. It will certainly be useful to known them in case you want to upgrade from an older systems.   The main requirements are:
• A processor (CPU) with a clock rate at least 1 GHz.
• At least 1 to 2 GB of memory (RAM), but Microsoft recommends 4 GB.
• At least 16 GB space in your hard disk.
The Windows 10 some features are the following:
• The Windows 10 desktop is simply your operating system main screen.
• An icon is simply graphic representation of an application or a file,
• Virtual desktop allows you to have multiple desktop screen.
• The “Search box” on the Taskbar will allow you to search within your documents and files or on the web for anything you write.
• The Notification Area is located at the right side of the taskbar. It shows different types of notifications from your computer like your internet connection, or the volume level, date and time etc.
Desktop Screen When you first switch on your machine, the Windows operating system loads and the first screen which appears is called the Desktop. Desktop is the main background screen of a computer. It is the background for all programs and contains the commands needed for accessing those programs. It is like your personal work area. You get a feel of what is inside your computer. Several icons or small pictures are located on the left side of the Desktop. You can use your Desktop for many tasks such as opening programs, copying files, connecting to the internet and so on. Certain icons are a permanent fixture on the desktop. The user can put other icons on the desktop that will quickly access programs or files ? like a shortcut. Icons can be moved around on the desktop by clicking and dragging them. You may have used the Paint icon in your computer lab for drawing pictures. The user interface is more...

#### Hands on With Paint Brush

Hands on With Paint Brush   Introduction Microsoft Paint or 'MS Paint' is a program or a basic graphic program that is included in all the Microsoft Windows versions. It can be used to draw, color and edit pictures, including imported pictures.   To open Paint Brush, do the following steps:
• Click Windows button and select “Window Accessories” folder from the start menu list.
• Select Paint
or
• To open MS-Paint type “paint” in the search box on the task bar and then select paint from the list of result.
Using Tools Free Hand Tools The Pencil and Brush tools allow for freehand drawing. The Pencil tool doesn?t have any options. It just draws a thin line in either the foreground color (left mouse button) or background color (right mouse button) In Pencil tool, the colors are chosen by using the left or right button for foreground color. The Brush tool has the option of a range of brush strokes, available from the option box that appears when the brush tool is selected.   Fill With Color A shape can be filled with color by using the fill color tool. Click on the fill with color tool, place it over the shape (object or area) to be filled and left or right  click depending upon whether the fore or background color is required. If the shape you want to fill has any breaks in its border, the fill color spreads to rest of the drawing area.   Text Text can be added to the image by first selecting the text tool and then drawing a box on the image area. When the box is completed the text toolbar will appear. Choosing fond, size etc. is the same as in other Microsoft programmes. The text color will be that of foreground color, to change the color of the text, click a color in the color box.   more...

#### Working With MS Word 2013

Working With MS Word 2013   Introduction World processing is an application program that allows you to create letters, reports, newsletters, tables, from letters, brochure and web pages. Using this application program you can add pictures, tables and charts to your documents. You also use check spelling and grammar checker.   Main Features of word 2013 MS Word 2013 has useful features, edit professional - looking user document using comprehensive set of easy to use tool provided by MS word.   Starting MS Word Program                   MS word 2013 Steps to start MS Word 2013 are following: (1) Click on start button. (2) The start menu will appear, select Microsoft office 2013. (3) Select word 2013 option.     Some Elements of MS Word 2013 windows are following:
• Ribbon: The Ribbon is the panel, above the document. It has nine tabs: Home. Insert, Design, Page Layout, References, Mailing, Review and View.
• Home: Clipboard, Font, Paragraph, Styles and Editing:
• Design: Themes, Watermark, Page color, Page Border.
• Page Layout: Page Setup, Paragraph, Arrange.
• Mailing: Create, Start Mail Merge, Write and Insert Fields, Preview, Result, Finish.
• Review: Proofing, Comments, Tracking, Changes, Compare, Protect
• View: Document views, Show, Zoom, Window, Macros.
• Rulers: The rulers display horizontal and vertical scales that reflects the width and height of your tying area
• Horizontal and Vertical Scrollbar: The scroll bar is placed at right and bottom of the document window.
• Status bar: The Status bar is placed at the bottom of the window. It. Display information about the current document like the number of pages and words etc.
Create a New document   To open a new document, follow the following steps:
• Click the tile tab.
• Select new option in the left pane. Then click blank document on the right side.
• A new blank document will appear on the screen.
more...

#### Trending Current Affairs

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