Current Affairs 4th Class

Measurement   Learning Objectives
  • Perimeter
  • Area
  In previous chapter, we have studied about shapes based on their properties. Perimeter and area are important concepts in our daily life as they widely applied by builders, painters, farmers, and gardeners. Perimeter is the total length of the boundary of a closed shape whereas the space inside the closed shape is its area. In this chapter, we will learn how to estimate and find the perimeter and area of geometrical shapes.  
  • A plane figure bounded by line segments and composed of angular corners is called a rectilinear figure. For examples, triangle, quadrilateral, hexagon, etc.
  • A circle is not a recti linear figure.
  • Length of the total boundary of a closed figure is called its perimeter.
  • Perimeter of a triangle is equal to the sum of the lengths of all its sides.
  • Perimeter of an equilateral triangle is thrice the length of its one side. Therefore, perimeter of equilateral triangle = \[3\times \text{side}\]
  • Perimeter of a rectangle is twice the sum of its length and breadth. Therefore, perimeter of rectangle = \[~2\times (\text{length}+\text{breadth)}\]
  • Perimeter of a square is four times the length of a side. Therefore, perimeter of square = \[4\times \text{side}\]
  • Area is the two-dimensional space covered by a surface. It is a measure of how much space is there on a flat surface.
  • Area of a rectangle is the product of its length and breadth. Therefore, area of rectangle = \[\text{length}\times \text{breadth}\]
  • Area of a square is the product of its any two sides. Therefore, area of square = \[\text{side}\times \text{side}\]
  •   Example:  
  • Amit wants new carpeting for his living room. His living room is a 8 m by 7 m rectangle. How much carpet does he need to buy to cover his entire living room?
  • (a) \[\text{64 }{{\text{m}}^{2}}\]                                 (b) \[\text{56 }{{\text{m}}^{2}}\] (c) \[\text{49 }{{\text{m}}^{2}}\]                        (d) \[\text{30 }{{\text{m}}^{2}}\] (e) None of these   Answer (b) is correct. Explanation: Here, length of the room = 8 m, and its breadth = 7 m Therefore, the area of room = \[\text{length}\times \text{breadth}=(8\times 7)\text{ }{{\text{m}}^{2}}=56\text{ }{{m}^{2}}\] Hence, Amit needs to buy \[\text{56 }{{\text{m}}^{2}}\] carpet to cover his entire living room.  
  • A square garden with a side length of 120 m has a square swimming pool in very centre with a side length of 20 m. Calculate the area of the garden.
  •   (a) \[14400\text{ }{{\text{m}}^{2}}\]                     (b) \[25600\text{ }{{\text{m}}^{2}}\] (c) \[10000\text{ }{{\text{m}}^{2}}\]                    (d) \[14000\text{ }{{\text{m}}^{2}}\] (e) None of these Answer (d) is correct. Explanation: Area of swimming pool = \[\text{side}\times \text{side}=(20\times 20)\text{ }{{\text{m}}^{2}}=400\text{ }{{\text{m}}^{2}}\] Area of the garden including swimming pool = \[\text{side}\times \text{side}=(120\times 120)\text{ }{{\text{m}}^{2}}=14400\text{ }{{\text{m}}^{2}}\] Therefore, area of garden = area of garden including swimming pool \[-\] area of swimming pool = \[\text{(14400}-400)\text{ }{{\text{m}}^{2}}=14000\text{ }{{\text{m}}^{2}}\]   3.            Perimeter of a square piece of gold is 22 millimetres. What is more...

    Data Handling   Learning Objectives
    • Introduction
    • Data
    • Bar Graph
    • Line Graph
    • Pie Graph
      Introduction Every day we come across a lot of information in the form of numerical figures, tables and graphs. These are provided by newspapers, televisions, magazines and other means of communication. These may relate to cricket batting or bowling average, temperatures of different cities, etc. The graphs are prepared with the help of data. Data are collected through survey or other means. Then data are arranged in ascending or descending order using table. In this chapter, we will study about graphs, how to make the graphs and how to extract information’s contained by the graphs.   Data Collection of information’s in the form of numerical figures in a survey is called data. The initial data that observer collects himself are called raw data. To extract the information’s contained by the data are arranged in ascending or descending order using tables. The raw data that have been arranged or organized by constructing a table are called grouped data. Data can be represented graphically to give clear idea of what it represent. It is easier to interpret and organise data using pictorial representation. Some of the ways in which data can be represented pictorially are:   Bar Graph A bar graph is a chart that uses bars to show comparisons between categories of data. It is an another type of graph used for showing data or information in a quick way. The bars can be either horizontal or vertical. Bar graphs with vertical bars are sometimes called vertical bar graphs. They are quite simple and easy to draw. Suppose the following data were collected regarding the number of employees in different companies. more...
    Our Body and Health   Interesting Facts
    •             Your mouth produces about one litre of saliva each day!
    •             A cell takes 24 hours to form and then divide to form new cells.
      ORGANS OF OUR BODY Our body is made up of cells. Cells are the smallest unit of life. Cells, which are similar in structure and function, group together and perform a common function. These group of cells are called tissues. Accordingly, many similar tissues combine together and perform a common function called organ. Eyes, nose, heart, brain, lungs, skin etc., are different organs of the body.     1. Digestive system Our body needs food to provide it with energy, vitamins, and minerals. The food is first broken down by the digestive system so nutrients can be released and used by our body for energy.   Do you know?
    •           The small intestine is the longest section of digestive tract
    •            Lungs are the only human organ that can float in water.
    •            Woman and children breathe at a faster rate than men.
    •           The small intestine is about 22 feet long. And about an inch in diameter.
    2. Respiratory system We take in air mostly through our nose, and then passes through the wind pipe into the lungs. The air we take in is called inhaled air. It is rich in oxygen. And the air, which is expelled from the lungs outside our body is called exhaled air, which is rich in carbon dioxide. This whole process of inhaling and exhaling of air is called respiration and the organs involved in the process are called respiratory organs. Breathing system can be simply represented as:   3. Skeletal system All the bones together form the skeletal system. Bones protect the soft organs of the body. Skeletal system is the framework of the bones. It gives proper shape strength and rigidity to the body. Femur bone is the longest more...

    Plants and Animals   Plants and animals are found practically everywhere. Some live on land, some under water and some in air. The surroundings where organisms live is called their HABITAT.   Interesting Fact
    •            If the spine of barrel cactus accidentally pricks , one may need to take antibiotics to combat its effects
      Do know 
    •           There are seven families of conifers. The largest is the pine family
        ADAPTATIONS Adaptations are special features in plants and animals which help them to survive in the habitats they live in. Over a long period, plants in a specific environment have developed special features which help them to live and grow in that particular habitat.     1. Terrestrial Plants [Plants Living on Land] Plants that grow on land are called terrestrial plants. There are various kinds of terrestrial plants depending on different habitats.                  (i)      Plants on mountains (cold hilly areas): In hilly areas like Ooty, Kashmir, Darjeeling, and the Himalayan ranges including Himachal Pradesh, the weather is cold in winter. Heavy snowfall can also be seen in these places. The plants that grow in these areas are tall and have a conical shape. They are flowerless. Instead of flowers, they have cones with seeds inside them. Leaves of these plants are needle-like. They have a wax coating to prevent any damage from snow. They have a triangular or conical crown. The sloping, shape of the trees makes the snow fall off easily.                  Coniferous trees: The trees that have straight and tall trunks to protect them from winter are called coniferous trees. They have needle- like leaves. The main plants of these areas are pine, spruce, cedar (deodar), and fir trees.                    (ii)     Plants in the plains: In plains, the weather is hot summers and cold in winters. The trees and plants us the plains mostly have many branches and lush green crowns. Teak, babul, shisham , palash, etc., are some of the common trees in the plains.   Do you know
    •             Approximately 75% of the species of trees found in the eastern deciduous forest of North America are deciduous trees.
      Teak                         Babul                      Shisham   (a) Evergreen trees:  Trees that remain green throughout the year are called evergreen trees. The trees shed their more...

    India and the World   We live in a diverse world. There are about 195 countries out of which India is the seventh-largest country in the world. Let us know more about India and the world around us.   Interesting Fact
    •            La Tomatina is festival that is held in spain in which participants throw tomatoes and get involved in the tomato fight purely for fun.
        1.            Snow and Ice festival. China - The Harbin festival is the largest snow and ice festival in the world, and it features ice carvings over 20 feet in height and full-size buildings made from gigantic blocks of ice.   2.            Holi India - Holi also known as the festival of colours is celebrated at the end of winter and the beginning of spring.   3.            Songkren Water Festival. Thailand - Songkran is Thailand's most famous festival. This water festival marks the beginning of the traditional Thai New Year.   4.            Diwali, India - Diwali or the festival of lights is usually celebrated in October or November. It is a five-day Hindu festival that celebrates the victory of good over evil.   5.            Lantern festival. Taiwan - Lantern Festival is a Chinese festival celebrated on the fifteenth day of the first month in the Chinese calendar. It marks the final day of the traditional Chinese New Year celebrations.   6.            Rio Carnival. Brazil - Carnival is an annual festival in Brazil. It is held four days before Ash Wednesday, the day of fasting and repentance that marks the beginning of Lent.   7.            Tomorrow land, Belgium ? Tomorrow land is c electronic dance music festival held in Boom, Belgium Tomorrow and was first held in 2005 and since then has become one of the world's largest and moi notable music festivals.   8.            Carnival of Venice, Italy - The Carnival of Venice an annual festival held in Venice, Italy. The festival world-famous for its elaborated masks.   9.            Coachella. California - The Coachella Valley Music an Arts Festival is an annual music and arts festival heat the Empire Polo Club in Indio, California.   10.          White Nights festival, Russia - It consists of series of classical ballet, opera and music events and includes performances by Russian dancers, singe. Musicians and actors, as well as famous international guest stars.   Do you know
    •             In China Christmas is more...

    Our Earth and Universe   The universe is everything we can touch, feel, sense, measure or detect. It includes living things, plants, star, galaxies, dust clouds, light and even time.   SOLAR SYSTEM The Sun and the eight planets with their moons make up the solar systems. The Sun is at the center of the solar system. All the planets and the smaller objects like comets, asteroids, meteorites, etc., revolve around the Sun. SUN The Sun is a star that emits heat and light. It is the largest member in the solar system. It gives sunlight. Plants need this sunlight to make their food using carbon dioxide, water, chlorophyll and minerals.   Interesting Fact
    •           One million Earth could fit inside the sun.
    •           The Sun Contains 99.86% of the mass in the solar system
      PLANETS   1.              MERCURY Mercury is the smallest planet in the solar system. It looks like our Moon. The surface of mercury is covered with craters. Though it is nearest to the Sun, it is less hotter than Venus. The reason is that the Mercury has no atmosphere to retain Sun's heat on it. 2.            VENUS Venus is a very beautiful object in the sky. It is called the evening star. Venus is also the brightest and hotter planet because it has atmosphere containing more amount of carbon dioxide. 3.            Earth This is the only planet in the solar system that has life it. Earth looks blue from the space because water cover about 3/4th of the planet's surface. This is the only planet with an atmosphere containing oxygen.    Do you know
    •           In 1632, Galileo Galilei discovered that the Earth revolves around the sun.
      4.            MARS Mars is the fourth inner planet. Mars is blood red colour due to presence of iron oxides on it. There is sign of water and life on this planet.   5. more...

    Environmental Conservation                  Natural Resources: Nature gives us many things. For example, forest, sun, wind, water, minerals, land, etc. The things that we get from nature is coiled natural resources.   TYPES OF NATURAL RESOURCES 1.            RENEWABLE RESOURES Renewable resources are the resources that are replenished by the environment over relatively short periods of time. Think of this like the ice cube maker in your refrigerator. As you take some ice out. More ice is formed. If you take a lot of ice out. it takes a little more time to refill the tray but not a very long time at all. Even if you completely emptied the ice cube tray, it would probably take only a few hours to refill that ice tray. Renewable resources in the natural environment work the same way. Solar energy Solar power from the sun is renewable as we won't "use up" all the sunlight from the sun.   Do you know
    •             Biogas is produced by breaking down the organic material in an oxygen free environment with the help of enzymes. 
      Wind   Wind is also a renewable source of energy. It cannot stopped or blocked by humans. Geothermal energy It is a renewable resource that provides heat from the earth.   Intersecting Facts
    •            Geothermal energy makes a minimal environmental impact.
    •            Human have enjoyed geothermal energy in the form of not springs for thousands of years
      Plants   Plants grown for food and manufactured products area renewable resources. Trees used for timber; cotton use for clothes; and food crops, such as corn and wheat, can be replanted and regrown after the harvest is collect. Animals  Animals are also considered a renewable resource beer like plants, you can breed them to make more. Livestock like cows, pigs and chickens all fall into this category.   2.          NON-RENEWABLE RESOURCES   Any natural resource from the earth that exists in life supply and cannot be replaced, if it is completely used is called a non-renewable resource, most fossil fuels, such as oil, natural gas, and coal are considered non-renewable resources. Their formation takes billions of years.   Non-renewable fuels like oil, coal, and natural gas more...

    Science and Technology   Today, we cannot expect our life without science and technology. Science and technology are extremely essential in our everyday life as they have made things more simple, fast and secured. Science and technologies are not only subjects. Rather, they means us ways and objects that help us live a better life!   Interesting Fact
    •             The average person walks the equivalent of five time around the world in a lifetime
      MATTER Matter is all around us. Matter is the air you are breathing. Matter is the computer you are reading from now. hotter is the stuff you touch and see. Matter is defined as anything that has mass and takes up space. Matter is found in 3 major states; solid, liquid and gas. All matter is made of atoms. Atoms are the smallest particles of matter.   Interesting Fact
    •             Matter has two types of properties; physical & chemical
    •            Most of the elements on the periodic table are made of slid matters
    •            Humans are made of all the three main states of matter.
      STATES OF MATTER The three states of waiter are solids liquids and gases.   Solid are objects that keep their own shape and do not flow in a given temperature. Ice is a solid but when it melts it becomes a liquid. Other examples of solids are cars, books and clothes. Solids can be of different colours and textures, and they can be turned into different shapes. For example, clay. Solids are made up of molecules which group together and don't move around. Solids hold their shape at room temperature. The pencil that you left in the desk at school will still be the same shape when you return tomorrow.   SOLIDS Solid are objects that keep their own shape but can take the shape of the container they are in and they can flow at a given temperature. Ice is a solid but when it melts it become a liquid. Other Examples of solids are cars, books and clothes.   Solids can be of different colours and textures, and they can be turned into different shapes. For example, clay. Solids are made up of molecules which group together and don?t move around.   Solids hold their shape at room temperature. The pencil that you left in the desk at school will more...

    Sports   Sports events have played pivotal role in communities around the world. Sports events, specially football world cup, commonwealth game, etc., attract millions of people. Let us know more about some sporting events.   SOME FAMOUS SPORTS EVENTS   1.            Icc World Cup - The ICC Cricket World Cup is the international championship of one -bay International (001) cricket. The event is organized by the sport's governing body, the International Cricket Council (ICC), every four years, with preliminary qualification rounds leading up to a finals tournament. The tournament is one of the world's most viewed sporting events and is considered the "Flagship Event of the International Cricket Calendar" by the ICC. 2.            Pro Kabbadi League - Pro Kabaddi League was conceptualized and founded by Mashal Sports promoted by Anand Mahindra, Charu Sharma and Rajiv Luthra. The leagues inception was influenced by the popularity of the Kabaddi tournament at the 2006 Asian Games. The format of the competition was influenced by Indian Premier League. 3.            Martial Art Camp- A martial art is a system of training for combat and self-defense that's widely practiced as a sport. There are camps and classes for each kind of martial art. Including karate, taekwondo, kung fu, and judo. These camps can take place in summers or winters. 4.            Indian Premier League- It is a professional T20 cricket league in India contested during April and May of every year by teams representing Indian cities and some states. The league was founded by the Board of Control for Cricket in India (BCCI) in 2008, and is regarded as the brainchild of Lalit Modi, the founder and former commissioner of the league.   Do you know
    •             The first men's cricket world cup was held in England in 1975
      5.            Notional Games-The National Games of India compnses various disciplines in which sportsmen from the different states of India participate against each other. The country's first few Olympic Games, now renamed as National Games, were held in North India (Delhi, Lahore Allahabad, Patiala, Madras, Calcutta, and Bombay.   6.            Junior Hockey World Cup- The Hockey Junior World Cup. is an international field hockey competition organised by the International Hockey Federation (FIH). The tournament was started in 1979.   7.            Commonwealth Games - The Commonwealth Games are an international multi-sport event involving athletes from the Commonwealth of Nations. The J event was first held in 1930, and has taken place every four years since then. The Commonwealth Games were known as the British Empire Games from 1930 to | 1950. It is the world's first multi-sport event which inducted more...

    Language and Literature   LANGUAGE AND LIERATURE Language is essentially a means of communication among the members of a society. There are roughly 6,500 spoken languages in the know about sone of them.   1.            Chinese- It is the official language of China and Taiwan, as well as one of the four official languages of Singapore. It is one of the six official languages of the United Nations.   2.            Spanish- There are many Spanish speaking countries in the world, as Spanish is the official language of the 20 countries, as well as Puerto Rico, Argentina, Bolivia, Chile, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Equatorial Guinea, Guatemala. Honduras, Mexico. Nicaragua. Panama, Paraguay, ...Apr 19, 2017   3.            English- There are more than 50 English speaking countries, where English is either the official or the primary language. It is the third most common primary language in the world (after Mandarin Chinese and Spanish).   4.            Hindi- Hindi is also spoken in some countries outside India, such as in Mauritius. Fiji, Suriname. Guyana, Trinidad & Tobago and Nepal. Just like European languages, Hindi is written from left to right   5.            Arabic- Arabic is the official language in Algeria, Bahrain, Comoros, Chad, Djibouti, Egypt. Eritrea, Iraq, Israel, Jordan, Kuwait, Lebanon, Libya, Mauritania, Morocco, Oman, Qatar, Saudi Arabia, Somalia, Sudan, Syria, Tunisia, United Arab Emirates, Yemen, Palestine, and Western Sahara.   6.            Portugese- Portuguese is an official language in about ten countries, including Brazil, Mozambique, Angola  Portugal, Gunea- Bissau , East Timor Equatorial Guinea , Macau , cape verde , and sao tome and principe   Interesting Facts
    •           The most popular language in the world is mandarin Chinese. There are 1,213,000,000 people in the world that speak that language
      7.            Bengali- It is spoken by more than 210 million people as a first or second language, with some 100 million Bengali speakers in Bangladesh; about 85 million in India, primarily in the states of West Bengal, Assam, and Tripura; and sizable immigrant communities in the United Kingdom, the United States, and the Middle East.   8.            Russian -If we're speaking about countries in which Russian is an official national language, then the list is Russia. Belarus, Kazakhstan, Kyrgyzstan and Tajikistan.   9.            Japanese- It is an East Asian language spoken by about 128 million people, primarily in Japan, where it is the national language. It is a member of the Japonic (or Japanese-Ryukyuan) language family, and its relation to other languages, such as Korean, is debated.   10. more...

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    Company Number of Employs
    Company A 300
    Company B 700
    Company C 500