Current Affairs 2nd Class

     Introduction   All celestial body, including our earth comes in our universe. Earth and other planets, all revolve around the Sun. The Sun and its planets are called solar system. Planet in our solar system has one or more satellite which is called the moon of the planet. In this chapter we will study about our universe and solar system.            Our Solar System The sun is exactly at the center of our solar system and planets revolve all around the Sun. The closest planet from the Sun in our solar system is the Mercury, and the last planet is Neptune. Pluto is another planet which is no longer considered as a full planet. It is now called dwarf planet. There is also a region in our solar system which is populated with smaller objects and lies between Mars and Jupiter, it is called asteroid belt.   Look at the following picture of our solar system:     The hotness and coldness of the planets in our solar system is depended on the distance from the Sun. The Mercury which is nearest to the Sun is the hottest planet in our solar system.            The position of our earth from the Sun in solar system is: (a) First (b) Second (c) Third (d) Fourth   Answer; (c) Explanation Our earth is third from the sun in our solar system. Therefore, option (C) is correct and rest of the options is incorrect.           Which one of the following planets is the first planet in solar system from the Sun? (a) Earth (b) Venus (c) Neptune (d) Mercury   Answer: (d) Explanation  The planet Mercury is the first planet in our solar system from the earth. Therefore, option (D) is correct and rest of the options is incorrect.

       Seasons   There are four seasons in India and they are given below:             Summer season This is a hot season. Summer stays from April to June. This is the season of sweating and scorching sun. Heat waves are common in this season. Therefore, light and cotton clothes are the most favorable clothes in summer season.              Rainy Season Rainy season comes after summer and it stays from July to September. This season is very necessary for agriculture because plants and crops need water to grow. But sometimes excessive rain causes flood and becomes reason of sufferings for human, plants and other living organisms.              Winter Season The months of November, December and January is the time of winter when the temperature is very low and the atmosphere is cold. This is the season when people wear woolen and warm clothes. In this season people may suffer from cold waves.              Spring Season This is the most pleasant season of the year. Because this is the season of moderate temperature when atmosphere is neither extreme cold nor extreme hot. This season stays from February to March.             How many main seasons are there in India? (a) Eight (b) Four (c) Nine   (d) Two   Answer: (b) Explanation Indian seasons are- summer, rainy, winter and spring. Therefore, option (B) is correct and rest of the options is incorrect.          Which one of the following month is the month of summer? (a) June (b) November (c) December (d) January   Answer: (a) Explanation  Summer stays from April to June. It means April, May and June are the months of summer. Therefore, option (A) is correct and rest of the options is incorrect.     We breathe almost two gallons of air every minute. Fresh water under the ground is much more in quantity than the fresh water on the surface of the earth. The sun evaporates a trillion tones of water every day. A person cannot survive for more than three days without water, but we can survive more than 30 days without food. Out of 100, 66% of our body is made up of water.     Air is the mixture of different like nitrogen, oxygen, carbon dioxide etc. Air contains 78 part nitrogen, 21 part oxygen and remaining 1 part other gases. Wind is the movement of air. There are mainly two types of wind-global wind and local wind. Wind is very useful because living organisms inhale air to more...

       Temperature Unit for temperature measurement is expressed in degree Celsius. In the cold or winter season temperature is low. Higher temperatures are referred to as warm or hot weather conditions. Temperature or heat is measured by thermometer.              Which one of the following is measured in degree Celsius? (a) Temperature (b) Pressure cooker (c) Gas stove (d) Fire   Answer: (a) Explanation Temperature is measured in degree Celsius. Therefore, option (A) is correct and rest of the options is incorrect.       Which one of the following is used to measure temperature? (a) Kilometer (b) Meter (c) Thermometer (d) Inch   Answer: (C) Explanation  Thermometer is used for the measurement of temperature. Therefore, option (C) is correct and rest of the options is incorrect.  

      Water   Water is the second most necessary requirement for the living organism. Living organism cannot survive without air for more than few minute. They also cannot survive without water for more than 3 days. Most part of our body is made up of water. Hence our body require water regularly because of excretion of waste water from the body.              Potable Water   Potable water is drinking water. This water is not polluted or contaminated and quality of this kind of water is high. Therefore, it can be used for drinking. If human and other living organisms do not get potable water they can suffer from waterborne diseases. Commonly water supplied in household is potable. People also use water purifier to make water potable. Persons who do not have access to potable water are prone to water borne diseases.             Sources of Water   Water is not man-made. It is a natural resource like air, sun, etc.   The following are the natural source of water:                                      Well                            Rain                         Ground water                    River                                     Pond                            Ocean                           Lake                            Glacier               Water on the Earth   Water is found in many places on the earth's surface, below the surface, and in the atmosphere. Water travels between different areas of the earth, known as the water cycle. Out of hundred, about 70 part of the earth surface is covered with water, and most of that is in the ocean. Only a small portion of the water of the earth is freshwater, which is found in rivers, lakes and groundwater. Freshwater is needed for drinking, farming, and washing. In addition to liquid water, water is also present on the earth in the form of ice. Without water, life is not possible.              States of Water   There are three states of water on the surface of the earth which are given below: more...

       Pollution   Pollution means contamination of unwanted substances that causes harm to human and other living organisms. Various kind of pollutions are given below:             Air Pollution  Air get contaminated in such type of pollution because of the following: Various kind of smokes from industry, vehicles and other things. Excretion of living organisms at improper places, ' Filthy and garbage materials lying at improper places. Sneezing and breath of living organisms carrying diseases.   Look at the following picture of the cause of air pollution:                   Water Pollution Water bodies (Seas, oceans, rivers, lakes ponds and groundwater) get contaminated when: Garbage, dirty materials are thrown in the rivers, ponds, lakes etc. Industrial wastes and chemicals get mixed into the waters of rivers, ponds, seas and lakes. Detergents are used while washing clothes and taking bath into rivers, lakes, ponds. Dead bodies of water animals cause water pollution.   Look at the following picture of the cause of water pollution:                   Sound Pollution or Environmental Noise Noise pollution means unbearable and displeasing sound to human and other living organisms.  The following causes noise pollution: Noise produced by mode of transportations like rail, vehicles, aircrafts etc. Industrial noise. Emergency service sirens Fireworks Loudspeakers, loud volume of radio, television, tape-recorders and other audio/ video entertainment systems. Barking dogs   Look at the following picture of the cause of noise pollution:                    Pollution means______________. (a) Purification (b) Education (c) Sanitation (d) Contamination   Answer: (d) Explanation Pollution means contamination. Therefore, option (D) is correct and rest of the options is incorrect.            Which one of the following is true? (a) A bad and offensive smell pollutes air (b) Pollution is good for health (c) Water cannot be polluted (d) Sound cannot be polluted   Answer: (a) Explanation  A bad and offensive smell pollutes air. Therefore, option (A) is correct and rest of the options is incorrect.

      Germs in Air   Germs are very small or tiny organisms that can cause disease. They are so small that they creep into our bodies without being noticed and start causing troubles. Germs in the air take birth because of the air pollution.   The following are the reasons for germs in air or airborne germs: Various kinds of smokes from industries and vehicles. Garbage and filthy materials at improper places. Excretions of living organisms at open spaces. Any kind of offensive smells. Sneezing and breath of living organisms carrying various germs.           Which one of the following is true about germs? (a) They have the size of an apple (b) They have the size of an Orange (c) They have the size of a banana (d) They are very tiny and cannot be seen with normal eyes   Answer: (d) Explanation  Germs are very tiny and cannot be seen through normal eyes. Therefore, option (D) is correct and rest of the options is incorrect.         Germs in the air causes ______. (a) Good health (b) Diseases (c) Laughter (d) No diseases   Answer: (b) Explanation Germs in the air causes diseases. Therefore, option (B) is correct and rest of the options is incorrect.

       Usefulness of wind   The following are the uses of wind: It is very important for living things as they inhale air to be alive. Most of the living things inhale oxygen and exhale carbon dioxide. While Plants inhale carbon dioxide and exhale oxygen. It is very important for the growth of plants. Fresh and cool air is needed for living things to be energetic and active. Fresh and natural air makes a good environment. It is used for electricity generation. Wind is used to fill in balloons, football, wheels of buses, cars, cycles, motorcycles etc.             Living things cannot ———— without air. (a) Eat (b) Live (c) Drink   (d) See   Answer: (b) Explanation Living things inhale air to be alive. Therefore, option (B) is correct and rest of the options is incorrect.           Which one of the following is true? (a) Wind is useless for living organism     (b) Wind is useless for plants (c) Wind is useless for human (d) Wind is the most important factor for the survival of living organism.   Answer: (d) Explanation  Wind is the most important factor for the survival of living organism. Therefore/option (D) is correct and rest of the options is incorrect.

     Types of Wind   Movement of air is called wind. There are mainly two types of wind depending on its motion. Global wind Local wind            Global Wind Global winds are the large movements of air that happen all over the world because of the following reasons; The rotation of the earth. The movement of the earth around the sun. Because of the round shape of the earth.            Local Wind Every region has their own type of winds. These winds are limited to that particular area and caused by temperature difference. They can move up, down and horizontal. Mountain areas are good example of such kind of winds. In these areas, wind blows against the mountain and is forced to go up. Because wind is usually going into one direction, the other side of the mountain almost does not have any wind.              Other General Classification of Wind            Breeze It is a light and pleasant air and not very fast moving air. Motion of air from sea to land is called sea breeze and land to sea is called land breeze.   Look at the following picture of land and sea breeze:                                    Sea Breeze                        Land Breeze             Storm Storm is a strong wind and it contains dust particles, snow and rain. Therefore, a storm may be categorized as dust storm, snowstorm, rainstorm etc. This type of wind can have a circular motion also. Cyclone is the perfect example of circular storm. This kind of wind may cause damages to trees, houses and other things.          Cold Wave Movement of cold air in winter is called cold wave. This is not a pleasant wind and harmful for living organisms. It may cause cold related diseases.          Heat Wave Movement of hot air in summer is called heat wave. This is not a pleasant wind and may cause summer related diseases.               Mainly winds are divided into_____ types. (a) Two (b) One (c) Three (d) Four   Answer: (a) Explanation  Winds are mainly divided into two group’s global and local wind. Therefore, option (A) is correct and rest of the options is incorrect.          Motion of air from sea to land or from land to sea is called breeze.     more...

     Introduction   Weather of a place is influenced by the condition of air and quantity of available water. Air is the mixture of different gases. Water is the chemical composition of hydrogen and oxygen. Both water and air is most important for living organism on the earth. Air always moves from high pressure area to low pressure area. This motion of air is called wind. In this chapter we will study about air, water and weather.        Air as a Mixture of Gases Air is not man made. It is a natural resource, and it is present everywhere. It cannot. be seen, and it is not exhaustible. Air is very important for living things because without air a living organism will die. This is the reason why air is called invisible friend of living organisms. Air is not a single component. In fact it is a mixture of different gases like nitrogen, oxygen, carbon dioxide, hydrogen, arson, neon, helium, krypton, xenon, radon etc. The total volume of air present in atmosphere consists of 78 part nitrogen, 21 part oxygen and remaining 1 part other gases.            Air is the mixture of________. (a) Gases (b) Solids (c) Water   (d) Soft drinks   Answer: (a) Explanation Air is the mixture of gases. Therefore, option (A) is correct and rest of the options is incorrect.           Which one of the following is not a part of air? (a) Argon (b) Orange (c) Nitrogen   (d) Carbon dioxide   Answer: (b) Explanation Orange is a fruit. Hence, this is not a part of the air. Therefore, option (B) is correct and rest of the options is incorrect.

    Soil   Soil is a thin layer of earth's crust, which serves as a natural medium for the growth of plants. In fact, soil is a source of minerals for plants. Plants also get water via soil, which is necessary for their growth. As life of human and other living organisms is fully dependent on plants, soil is also very important for the life of living organisms.   Look at the following picture of different types of soil:                                              Clay soil                                             Sand soil                                          Loamy soil              Which one of the following is true? (a) Soil is not important for man (b) Soil is not important for woman (c) Soil is not important for animals (d) Soil is very important for the life of living organisms   Answers: (d) Explanation  Soil is important for the life of living organisms. Therefore, option (D) is correct and rest of the options is incorrect.           A plant cannot grow without _____. (a) Flower (b) Fruit (c) Vegetables (d) Soil   Answer: (d) Explanation Soil is an important requirement for the growth of plants. Therefore, option (D) is correct and rest of the options is incorrect.     Area of deserts are increasing continuously. Near about 64, 000 square miles of rain forests are destroyed each year. Nile river of Africa is the largest river on the earth. Blue whale is the largest animal. Australian saltwater crocodiles are the largest living reptiles on the earth.     Atmosphere is the mixture of gases surrounding celestial body, The atmosphere of earth is mixture of gases. Sea is a large saline water body and natural source of water. River is natural source, of fresh water and flows into a oceans, seas, lakes and another river. Lakes are inland having fresh or salt water. Lakes are both natural and artificial. Soil is very important for human and other living organisms as it provide nutrients for plants to grow. Plants absorb water from soil.