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Current Affairs 7th Class

Ratio and Proportions, Percentage and S.I. and C.I.

Ratio and Proportions, Percentage and S.I. and C.I.   Ratio A ratio is a relation between two quantities of same kind, The ratio of a number x to another number y (where\[y\ne 0\]) is written as x : y.  
  •               Example:
Daniel wants to divide ` 1530 between David and Michael in the ratio 8 : 9. Find the amount received by David.             (a) ` 720                                                           (b) ` 810                    (c) ` 900                                                            (d) ` 820             (e) None of these Ans.     (a)             Explanation: Amount received by David \[=\,\,Rs.\,\,\frac{1530}{17}\times 8=Rs\,\,720\]   Proportion A proportion is a name we give to a statement when two ratios are equal. It can be written in two ways:
  •               \[\frac{a}{b}=\frac{c}{d}\,\,(two\,\,equal\,\,fractions)\]                \[a:b::c:d\,\,~\left( using\text{ }a\text{ }colon \right)\]
When two ratios are equal then, their cross products are equal. That is, for the proportion, \[a\text{ }:\text{ }b=c:d,\text{    }a\text{ }\times \text{ }d==b\,\,\times \,\,c\] In the proportion \[a:\text{ }b\text{ }::\text{ }c\text{ }:\text{ }d\], a and d are called extreme terms and b and c are called mean terms.  
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Catgeory: 7th Class

Data Handling

 Data Handling   Modern society is information oriented. Every person wants numeric information of different fields of the society like the marks obtained in a particular subject by the students, five year plans etc. Statistics is a branch of mathematics which deals with the process, analyzing and interpreting the data.   Terms Related to Data
  •               Data: It is defined as the particular information in numeric form.
  •              Primary data: Primary data means the data that have been collected by collector for some purpose.
  •              Secondary data: Secondary data is data that have been collected by others and used by other observer.
  •              Raw data: It is the original form of the data.                                
  •              Frequency: The number of times a particular observation occurs in a data is called frequency.
  •             Range: The difference between maximum and minimum value of the observation is called range.
  •             Class Interval: The interval in which variates lies is called class interval.
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Catgeory: 7th Class

Number System and Operations

      Number System and Operations   Integers Integers are the set of all positive and negative numbers including zero.   Addition of Integer
  •         The sum of two integers is an integer or integers are closed under addition.
  •        The sum of two integers is commutative.
  •        The addition of integers is associative.
  •        0 is the additive identity for integers.
  Subtraction of Integers Integers are closed under subtraction but they are neither commutative nor associative. Thus, if a and b are two integers then a - b is also an integer.   Multiplication of Integers
  •     The product of two integers is an integer or integers are closed under multiplication.
  •      The product of two integers is commutative.
  •      Multiplication of integers is associative.
  •     1 is the multiplicative more...
Catgeory: 7th Class

Exponents

 Exponents   Exponents The continued product of a number multiplied with itself a number of times can be written in exponent form as an, where ?n? is a natural number and ?a? is any number. i.e., an = a \[\times \] a \[\times \] a ..... up to n times. Here a is the base and n is exponent (or index or power). For any rational number \[\left( \frac{p}{q} \right),\text{ }{{\left( \frac{p}{q} \right)}^{n}}\text{= }\frac{p}{q}\times \frac{p}{q}\times \frac{p}{q}\times ............\] up to n times   Laws of Exponents The following are the laws of exponent:
  •                 \[{{x}^{m}}\times \text{ }{{x}^{n}}={{x}^{m+n}}\]
  •                 \[\frac{{{x}^{m}}}{{{x}^{n}}}={{x}^{m-n}}\]
  •                 \[{{x}^{m}}\times {{\text{y}}^{\text{m}}}\text{ = (}x\times y{{\text{)}}^{\text{m}}}\]
  •                 \[{{\left[ {{\left( \frac{x}{y} \right)}^{n}} \right]}^{m}}={{\left( \frac{x}{y} \right)}^{mn}}\]
  •                 \[{{\left( \frac{x}{y} \right)}^{-n}}\text{ =}{{\left( \frac{y}{x} \right)}^{n}}\]
  •                \[x{}^\circ =1\]
  •                \[{{x}^{1}}=x\]
  •                \[{{x}^{-1}}=\frac{1}{x}\]
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Catgeory: 7th Class

Algebraic Expressions and Linear Equation

Algebraic Expressions and Linear Equation   Algebraic Expression Algebraic expression is the combination of constants and variables along with the fundamental operations\[(+,-,\times ,\div )\]. The part of an algebraic expression which is separated by the sign of addition and subtraction are called terms.   Types of Algebraic Expression T-re following are the few types of algebraic expression:
  •                Monomials
  •                Binomials
  •               Trinomials
  Finding the Value of an Algebraic Expression To find the value of an algebraic expression, first simplify the given algebraic expression if possible and replace the variable with given numerical value.  
  •                Example:
List the following algebraic expression into monomial, binomial or trinomial: \[\mathbf{3}{{\mathbf{z}}^{\mathbf{2}}},\text{ }\mathbf{3a}\text{ }+\text{ }\mathbf{4b}\text{ }+\text{ }\mathbf{5c},\text{ }{{\mathbf{a}}^{\mathbf{3}}}+\text{ }{{\mathbf{b}}^{\mathbf{3}}}-\text{ }\mathbf{3ab},\text{ }\mathbf{5a},\text{ }\mathbf{6x}\text{ }+\text{ }\mathbf{4y},\text{ }\mathbf{35x}\text{ }+\text{ }\mathbf{5y}\text{ }-\text{ }\mathbf{35}\text{ }\left( \mathbf{x}\text{ }-\text{ }\mathbf{y} \right)\] Solution: Monomial: \[3{{z}^{2}},\text{ }5a,\text{ }35x\text{ }+\text{ }5y\text{ }-\text{ }35\left( x\text{ }-\text{ }y \right)\], as these have only one term.             Binomial: \[6x+4y\], because it has only two terms.             Trinomial: \[3a\text{ }+\text{ }4b\text{ }+\text{ }5c,\text{ }{{a}^{3}}+\text{ }{{b}^{3}}-\text{ }3ab\], because they have only 3 terms.   Algebraic Identities
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Catgeory: 7th Class

Algebraic Expressions

Algebraic Expressions   In an algebraic expression constant and variables are linked with arithmetic operations. The value of unknown variable is obtained by simplification of the given expression.   TERMS OF AN ALGEBRAIC EXPRESSION Literals or Variables Alphabetical symbols used in algebraic expressions are called variables or literals. a, b, c, d, m, n, x, y, z ........... etc. are some common letters which are used for variables.   Constant Terms The symbol which itself indicate a permanent value is called constant. All numbers are constant. \[6,\text{ }10,\,\,\frac{10}{11},\text{ }15,\text{ }-6,\text{ }\sqrt{3}\text{ }....\] etc. are constants because, their values are fixed.   Variable Terms A term which contains various numerical values is called variable term. For example, Product of 4 and \[X\text{ }=\text{ }4\text{ }\times \text{ }X\text{ }=\text{ }4X\] Product of \[2,\text{ }X,\text{ }{{Y}^{2}}\]and \[Z\text{ }=\text{ }2\text{ }\times \text{ }X\text{ }\times \text{ }{{Y}^{2}}\times \text{ }Z\text{ }=\text{ }2X{{Y}^{2}}Z\] Thus, 4X and \[2X{{Y}^{2}}Z\] are variable terms   Types of Terms There are two types of terms, like and unlike. Terms are classified by similarity of their variables.   Like and unlike Terms. The terms having same variables are called like terms and the terms having different variables are called unlike terms. For example,\[6x,x,,-2x,\frac{4}{9}x,\], are like terms and\[6x,2{{y}^{2}},-9{{x}^{2}}yz,4xy,\], 4xy, are unlike terms.   Coefficient A number or a symbol multiplied with a variable in an algebraic expression is called its coefficient. In \[-\text{ }6{{m}^{2}}\]np, coefficient of\[n{{m}^{2}}\]p is -6 because \[{{m}^{2}}\]np is multiplied with -6 to form \[-\text{ }6{{m}^{2}}\]np. The variable part of the term is called its variable or literal coefficient. In\[-\frac{5}{4}\] abc, variable coefficients are a, b and c. The constant part of the term is called constant coefficient. In term\[-\frac{5}{4}\], abc, constant coefficient is\[-\frac{5}{4}\].  
  •         Example:
Sign of resulting addition of two like terms depends on which one of the following? (a) Sign of biggest term                (b) Sign of smallest term (c) Sign of positive term            (d) Sign of negative term (e) None of these Answer (a)   Operations on Algebraic Expressions When constant and variables are linked with any of the following fundamental arithmetic operations i.e. addition, subtraction, multiplication and division, then the solution of the expression is obtained by simplification of the expression.   Addition and Subtraction of Terms The addition of two unlike terms is not possible and their addition is obtained in the same form. Addition of 2x + 3x is 5x but the addition of 2x + 3y is 2x + 3y. Subtraction of two like terms is same as the subtraction of whole numbers. For example, 4x - 2x = 2x  
  •        Example:
Simplify: \[\left( \mathbf{2}{{\mathbf{x}}^{\mathbf{2}}}\mathbf{+}{{\mathbf{x}}^{\mathbf{2}}} \right)\mathbf{ - }\left( \mathbf{5}{{\mathbf{x}}^{\mathbf{2}}}\mathbf{+11}{{\mathbf{x}}^{\mathbf{2}}} \right)\] (a) \[15{{x}^{3}}\]                                                                   (b) \[15{{x}^{2}}\]          (c) \[-3{{x}^{2}}\]                                                                    (d) \[13{{x}^{2}}\] (e) None more...
Catgeory: 7th Class

Basic Concepts of Operating System

Basic Concepts of Operating System   Introduction The word operating system is self-indicating that this is a system for operating a devise. An operating system is a program which acts as an interface between a computer hardware and users of the computer. It provides such an operating system, the primary goal is to make computer system convenient to use and the secondary goal is to use the computer hardware in an effective manner. The OS helps in a file management, program execution, system management and memory management. Some popular operating system are: LINUX, Window, OSX, VMS, AIX OS/400, Z/OS etc.   Main Layers in an Operating System        Layers in an Operating System is defined as the software which provides interface between different components of the computer. The following five layer model is often used in an Operating System.  
  • Kernel: It connects the application software to the hardware of a computer. Hence, it manages memory access for programs in the RAM. It also allocates processor time and memory to each program and determines when each program will run.
  • Memory Management: It is responsible for starting the physical memory of the computer between processes and handling programs which require more memory than physically available.
  • Input/Output: This layer controls all physical communication with external devices like disk drive, keyboard, printer and display. If a higher layer require access to a device, a request is sent to the I/O layer.
  • File Management System: It is also known as file system. It is responsible for organising and managing the storage of data on permanent media such as hard and floppy disk drives and tape streamers.
  • User Interface: It is defined as the space where interaction between human and machine occurs. There are two types of user interface: the text-based Command Line Interface (CLI), used in MS-Dos and LINUX, and the icon-based Graphical User Interface (GUI), used in windows and Apple Mac OS.
        Classification of Operating System is as follows:   v  Multiprocessing: Supports in running a program on multiple CPUs within a single computer system. v  Multitasking: Allows you to run more than one program at the same time. v  Multi - user: Allows multiple user to run the program at same fraction of time. v  Multithreading: Permits all different modules of a single program to run at the same time. v  Real - Time: responds to input immediately.   Microsoft Windows Microsoft windows is a type of Operating System available in 32 and 64 bit versions. It was developed by Microsoft. It provides a Graphical User Interface (GUI), virtual memory management capabilities, multitasking functionalities and support for many peripheral devices.   Earlier in Microsoft Windows Operating System, there was more...
Catgeory: 7th Class

Flowchart and Computer Languages

Flowchart and Computer Languages   Introduction Computer programming language is defined as the type of language used for writing the source code of computer program, whereas, computer programs are set of instructions that enable a computer to interact with the user, peripherals and information. These instructions are written in a language called computer programming language. The process of writing computer programs is called computer programming. Before writing a computer program, first you have to develop an algorithm. An algorithm is a group of logical instruction that generates the output according to given input. These algorithms are written in Pseudocode. Pseudocode is an informal description of a computer program that is written in simple English.   While writing a program using a computer programming language, such as C, you need to follow the syntax of that language. A programming language also provide operators that enable you to perform various tasks, such as computing and manipulating values of variables, comparing values of different variables of same data types and testing multiple conditions. After developing algorithm, you need to develop flowchart.   How to Develop Flowchart Flowchart is a technique that allows you to represent computer program graphically. Each step in the flowchart is represented by a different symbol and contains a short description of the step. Using flowchart, you can easily understand the logic of a program. A flowchart represents the logical and operational steps to be performed within the system for transforming the input process into output. Flowchart serves as a basis for discussion and communication between the system analysts and the programmers.   To create a flowchart, you need to use the following symbols:  
Symbol Description
This symbol is used to represent the start and end of an algorithm or process. It is also called terminator box.
This symbol is used to represent the logic used in a process or algorithm. It is also called processing box.
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Catgeory: 7th Class

Networking and Internet

Networking and Internet   Introduction A computer network is a group of computers that are interconnected to share information and resources. The first networks were implemented by both IBM's SNA Systems Network Architecture) and Digital's network architecture. Internet is the biggest example of computer networking. Through Internet you can send email or file to any location in the world. While developing computer network, you need to use communication devices, such as modem and router. Basically, communication devices are usefull to send and receive data on the network.   Network means connecting with each other. Computers form network for sharing information and resources. A number of computers and peripheral devices are interconnected in such a way that they can share resources and information. This is known as network. Networking is mainly concerned with the communication between computer systems. A computer network is any set of computers connected to each other with the ability to exchange information. Computer networking can be considered as a sub discipline of computer science, information technology and computer engineering.   Different Types of Networks Computer network is divided into three main categories:     LAN LAN is commonly known as Local Area Network. It is used to connect the computers - --d other network devices so that the devices can communicate with each other to share the resources. The resources to be shared can be a hardware like printer or a software like an application program or data. The size of LAN is usually small. The various devices in LAN are connected to central devices called Hub or switch using a cable. This network is limited to a relatively small area, such as a classroom, a school or a single building. This type of network has the lowest cost.   Advantages of LAN   v  Ability to share hardware and software resources. v  All network users can save their data on hard disk of the server computer. v  Components and system evolution is possible. v  Support for heterogeneous forms of hardware and software. v  Access to other LAN's and WAN's. v  Private ownership. v  Secure transfers at high speeds with low error rates.     Disadvantages of LAN   v  Equipment and support can be costly. v  Some types of hardware may not interoperate. v  A good LAN is required to be on all the times. v  A lot of times a network shares one internet connection only. If many computers are running at once, it can reduce more...
Catgeory: 7th Class

Working With Microsoft Word 2013

Working With Microsoft Word 2013   Introduction The Microsoft Word brings new revolution in documentation. Windows platform of Word was released in 1989. Since 1989, many versions of Word has been launched by Microsoft, such as Word 95, Word 97, Word 2000, Word 2002, Word 2003, Word 2007, Word 2010, Word 2013 and word 2016.   Microsoft Word is a popular word processing software that allows the user to create more accurate, concise and correct documents. It's also useful to create brochures, memos, merging letters and newsletters. Microsoft Word enables you to create documents using text formatting, graphic, chart and page formatting tools. Using Microsoft Word, you can add text, tables and graphics more easily.   Word enables various features that allow creating different kinds of documents.   Important Elements in Word 2013  
Element Description
Title bar: Displays the name of the active document and it is present at the top of the window.
Ruler: Word contains two types of ruler including horizontal and vertical. Ruler provide measurement of ongoing page as well as quick access to margins, tabs and indents. It is present below the toolbar and on the left side of the application window.
Scroll bars: Allows viewing different areas of the active document. It is positioned along the right side and bottom of the text area.
Status bar: Displays various types of information about the active document, such as the current page number. It is positioned across the bottom of the application window.
Minimize button more...
Catgeory: 7th Class

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