Current Affairs 4th Class

          Monitor     The monitor or the VDU (visual display unit) is the most common form of output from a computer. The Monitor is an output device that resembles the television screen and uses a CRT (Cathode Ray Tube) to display information. The picture on a monitor is made up of tiny coloured dots called pixels. The monitor is associated with a keyboard for manual input of characters and displays the information as it is keyed in. It also displays the program or application output. Thus, the monitor displays the results of the computer's activities on the screen. Like the television, monitors are also available in different sizes. The display device in modern monitors is typically a TFT-LCD (Thin Film Transistor Liquid Crystal Display). (See Figure 4.1.4)                Match the Following:           A                                           B 1. VDU                                            i.   Modern display unit 2. CRT                                            ii.   Output device 3.   TFT-LCD                                  iii.   Display the information (A) 1, iii; 2, i; 3, ii                                                (B) 1, ii; 2, iii; 3, i (C) 1, i; 2, ii; 3, iii                                                (D) 1 ii; 2, i; 3, iii (E) 1, iii; 2, ii; 3, i     Answer: (B) Explanation Correct Option: (B) Option (B) is matched correctly. Incorrect Options: (A) Option (A) is matched incorrectly. Therefore, option (A) is incorrect. (C) Option (C) is matched incorrectly. Therefore, option (C) is incorrect. (D) Option (D) is matched incorrectly. Therefore, option (D) is incorrect. (E) Option (E) is matched incorrectly. Therefore, option (E) is incorrect.          Fill in the blanks: 1. The picture on a monitor is made up of________ called pixels. 2. The monitor is associated with a ___________ for manual input of characters. 3. The monitor uses __________ to display information. (A) Big coloured dots, Mouse, LCD (B) Small holes, Keys, TFT (C) Tiny coloured dots, Keyboard, Screen (D) Tiny B/W dots. Keyboard, VDU (E) Tiny dots. Mouse, CRT     Answer: (C) Explanation Correct Option: (C) Options given in (C) are correct. Incorrect Options: (A) Options given in (A) are incorrect. Therefore, option (A) is incorrect. (B) Options given in (B) are incorrect. Therefore, option (B) is incorrect. (D) Options given in (D) are incorrect. Therefore, option (D) is incorrect. (E) Options given in (E) are incorrect. Therefore, option (E) is incorrect.  

   Mouse     A mouse is a pointing device with a roller on its base. A mouse makes the process of navigating the screen much easier than trying to use just a keyboard. A mouse controls the movement of a pointer (also called mouse pointer) on the screen. When a mouse moves on a flat surface, the cursor on the screen also moves in the direction of the mouse's movement. A mouse usually uses a ball, light or a laser to track movement.   The mouse is a small device used to point to a particular place on the screen and select in order perform one or more actions. It can be used to select menu commands, resize windows, start programs, etc. The most conventional kind of mouse has two buttons on top where the left one is used more frequently than the right one. The mouse helps us to 'point at' and 'input' data by Single Clicking, Double Clicking and Dragging with the Left Mouse Button and Single Clicking with the Right Mouse Button. A mouse is a pointing device where the mouse's motion typically translates into the motion of a cursor on a display, which allows the control of a GUI (Graphical User Interface). The name mouse, originated at the Stanford Research Institute because of its resemblance to the common mouse with a tail.                Alex and Bryan are discussing about mouse. Read their conversation and select whose statements are correct. (1) Alex - A mouse is a common pointing device with a roller on its base. A mouse controls the movement of a pointer on the screen. (2) Bryan - A mouse makes the process of navigating the screen much difficult than trying to use just a keyboard. (A) (1) Alex is correct                                      (B) (2) Bryan is correct (C) 'Both (1) and (2) are partially correct (D) Both (1) and (2) are correct                  (E) None of these     Answer: (a) Explanation Correct Option: (A) The information given by Alex is correct. Incorrect Options: (B) The information given by Bryan is incorrect. Therefore, option (B) is incorrect. (C) Alex is fully correct where as Bryan is fully incorrect. Therefore, option (C) is incorrect. (D) Both of them are not correct. Therefore, option (D) is incorrect. (E) Both of them are not incorrect. Therefore, option (E) is incorrect.            Fill in the blanks: 1. A mouse usually uses a ball, _______ or a ________ to track movement. 2. The most conventional kind of mouse has _______ buttons on top. 3. The __________ mouse button is used more frequently than the ________ one. (A) Bat, laser, three, right, left                   (B) Light, laser, two, left, right (C) Beam, light, four, upper, lower           (D) Ray, sound, one, top, more...

     Keyboard     The keyboard is the most common input device which is used to type the letters, digits and commands. It is an essential or standard input device. A keyboard is a typewriter like device which contains a matrix of switches (one switch per key). It typically has characters engraved or printed on the keys and each press of a key typically corresponds to a single written symbol. When a key is pressed, it sends a digital code to the computer which determines which key has been pressed. For example, if you press 'A' when Caps lock is on, a code 01000001 is sent to the computer. The computer then translates this code to determine that you pressed 'A'. However, to produce some symbols requires pressing and holding several keys simultaneously or in sequence. While most keyboard keys produce letters, numbers or signs (characters), pressing other keys or simultaneous key can produce actions or computer commands. Normally, the keyboard is used to type text and numbers into a word processor, text editor or other programs. Keyboards are also used for computer gaming, either with regular keyboards or by using keyboards with special gaming features, which can speed up frequently used    keystroke combinations. A keyboard is also used to give commands to the operating system of a computer, such as Control-Alt-Delete combination in Windows, which brings up a task window or shuts down the machine.                  Given below is the information about keyboard. Read and identify the correct one. 1. Each key on the keyboard has characters engraved or printed on it. 2. When a key is pressed, it does not send any digital code to the computer. 3. After switching off the caps lock, if you press 'A', a code 01000001 is sent to the computer. (A) 1 and 3                                                          (B) Only 1 (C) 2 and 3                                                           (D) All of these (D) None of these     Answer (B) Explanation Correct Option: (B) Only statement 1 is correct about keyboard. Incorrect Options: (A) Statement 1 is correct but statement 3 is incorrect. Therefore, option (A) is incorrect. (C) Statements 2 and 3 are incorrect. Therefore, option (C) is incorrect. (D) All the given statements are not correct. Therefore, option (D) is incorrect. (E) All the given statements are not incorrect. Therefore, option (E) is incorrect.         Fill in the blanks: 1. A keyboard is also used to give commands to the ________ system of a computer. 2. To shut down a computer ________ key combination is used. 3. A keyboard is a ________ like device which contains a matrix of ________ (A) Operating, Shift + Alt + Delete, Button, Switches (B) Control, Tab + Ctrl + Backspace, Typewriter, Plug (C) Operating, Ctrl more...

    Introduction     A computer peripheral is any external device which provides input and output for the computer. For example, a keyboard and a mouse are input peripherals while a monitor and a printer are output peripherals. Computer peripherals or peripheral devices are sometimes called "I/O devices" because they provide input and output to the computer. Other peripherals are outside the computer case, such as the printer and image scanner, attached by a wired or wireless connection.                 Some commonly used Input/ Output devices are listed in the following table: INPUT DEVICES                               OUTPUT DEVICES Keyboard                                           Monitor Mouse                                                LCD Joystick                                              Printer Scanner                                              Plotter Light Pen Touch Screen    

         Natural Phenomenon Related To Planets and Stars   The natural phenomenon in the universe, which is associated with the heavenly bodies, like sun, earth, moon, etc., is spinning on their axis, an imagining line on which they spin.              Rotation of Heavenly Bodies When the axis of rotation lies within the body of the object itself, the body is said to rotate upon itself or spin. Most of the heavenly bodies in our galaxy like the planets, moon and the sun spin or rotate upon itself. This spin is better known as rotation. While rotating these bodies move around a central point called revolution. The process of revolution is not a property of planets alone. Moons also revolve with planet at its centre Sun and the other stars revolve around the centre of our galaxy. Our solar system has eight planets with their moons and the sun. The moon spic around itself while moving around their respective planets in their fixed orbit All the planets in a similar manner spin on their axis while they revolve around the sun Most of the planets in our solar system, including the earth spins in the same direction as they orbits the sun. The two exception to this are the planet venus and uranus. Now let us look the effect of rotation and revolution on earth and its effect on us Te Earth spins around a line passing through its centre. Axis of earth is tilted at an angle of 23.5°. This titled imaginary line is called the axis o rotation. We all know that the rotation causes day and night. Earth completes one rotation in 24 hours. Thus our one day is 24 hours long. When the earth rotates on its axis, half of the earth faces the sun and it is day then that part. At the same time half of the earth which is away from the sun are dark and so that part has night time. This is the reason for the difference in the time across the world. When it is active day time in our country, people of America has night. Rotation of the Earth around Its Axis              Revolution of Heavenly Bodies Revolution is the movement of the earth around the sun in its fixed orbit. The time taken by the earth to complete one revolution is approximately 365.24 days. This is considered as 1 year. The revolution of the earth around the sun causes change in season. The main reason for the different seasons is the tilted axis on which the earth spins.                                           Showing the Revolution of the Earth   Depending upon which hemisphere of the earth is closer to more...

     Environment   Environment is the natural surroundings of a living thing in which it lives and survives. Environment is everything that makes up the surrounding of a living thing.                                                                                                                                                   Natural Environment   Environment comprise of both living (biotic) and non living things (abiotic). The non living things in the environment are sunlight, water, air, temperature etc. The living things in the environment are human, plants, animals, etc. Each living thing has its own environment where it lives and grows. For example environment of a plant are sunlight, weather, air, water, soil in which it grows and the animal that consumes it. We, human beings, depend on our environment for all our need?. Each of the living things depends on the other living and non living thing in its environment for its survival. Humans, while making life more comfortable for themselves, have damaged the environment in which they live, in many ways. Our actions are causing disastrous change in the environment. We exploit our environment to our maximum utility and in turn do nothing for its good. The condition is very alarming and needs proper thinking and action. We should do everything possible to save our environment before it is too late..

       Eclipses   Eclipse is a play of light and shadow. Eclipse simply means shielding away or hiding away something in ones shadow. Focus a torch towards a wall. Now put your hand between the wall and the lighted torch. Can you see the shadow of the hand on the wall? Yes, this is what happens during the eclipses. This process of shadow formation and shielding of one object's view happens in space too. The Earth and the Moon also cast shadow in space when sunlight falls on them. This causes solar and lunar eclipses. Simply we can say that depending on the shadow cast and the view of the heavenly body i.e. sun or the moon being blocked in the shadow from the earth’s surface. It is either solar eclipse (sun's view blocked) or lunar eclipse (moon's view blocked)            Solar Eclipse The earth orbits the sun and moon orbits the earth. While on their respective paths, it so happens that moon comes in between the sun and the earth. It then blocks the light of the sun and cast a shadow on the earth. People in the shadow area, can't see the sun. Solar eclipse occurs only on a new moon when the sun, moon and earth are in a line. There are two types of solar eclipse depending on the amount of shadow formed and the view of the sun blocked/total solar eclipse and partial solar eclipse.                      Solar Eclipse              Total Solar Eclipse Total solar eclipse occurs when the dark shadow of the moon completely blocks the intense sun. Total solar eclipses are very rare celestial phenomenon. During a total solar eclipse, sun seems to disappear during the day and the sky darkens in a few minutes. Total solar eclipse also depends on the position of moon and the earth in its specific orbit. An eclipse that occurs when the moon is near its closest distance to the earth and the earth approaches its farthest distance from the sun, is a total solar eclipse. Because the moon will then appear to be large enough to cover completely the sun's bright side in its shadow. Total solar eclipses are beautiful celestial events, which can never be more than for a few minutes. In a year five to seven solar eclipses occur. No more than two eclipses happen to be a total solar eclipse. Total solar Eclipse              Partial Solar Eclipse The other type of eclipse is called the partial solar eclipse. Can you guess anything from the name? Yes, it is only a portion and not the complete thing itself. Partial solar eclipse occurs when a more...

     Satellites   Satellites are free flying objects that move around a planet. There are mainly two types of satellites, natural and artificial. Natural satellites as the name suggest, are naturally present in the space. They are the heavenly bodies formed along with the planets and the stars of the galaxies. Artificial satellites or manmade satellites are those free flying objects that are orbiting the earth or planet and used for various purposes like communication, weather information etc. Most of the planets in our solar systems have their own natural satellites. The inner planets (planets close to the sun) have less number of natural satellites when compared to the outer planets. Earth, the 3rd planet from the sun has only one satellite. We better know it as moon. The red planet mars has two satellites. The outer four planets of our solar system is known for many satellites. Jupiter, the largest planet is said to have as many as sixty four (64) known moons. Jupiter's moons are of different types. Some of them are much bigger than earth's moon, where as some are tiny, only a few miles across. The ringed planet, Saturn is said to have sixty two (62) moons orbiting it. Titan is the largest moon of Saturn. Uranus is known till date to have twenty (20) moons. Neptune is the farthest planet having eight (8) known moons. The number may be more.            Moon Moon, which looks the brightest and biggest on a dark night is the only natural satellite of the earth. There is no life on the moon because of extreme temperature. This extreme temperature is due to lack of atmosphere. On the moon, as there is no atmosphere it becomes boiling hot during the day and freezing cold at night. Moon does not have light of its own. The bright moon as we see, is due to the reflection of sun's light from its surface.       Moon of the earth       The surface of the moon is dusty and barren. There are many craters of different sizes on its surface. It also has large number of steep and high mountains. We can see mountains and craters on the moon from the earth with the help of a telescope. Most interesting fact about the moon is that its lighted or the bright part changes its shape every day. This is because, as we already known that, moon doesn't have any light of its own. It reflects the light of the sun. When the moon moves in its orbit around the earth, different portion of the moon's surface reflects light from the sun. It is only that part of the moon, which reflects sunlight is seen by us and the rest of the moon is dark. This increasing and decreasing size of the lighted part of the moon is more...

       Introduction   Our Universe: Universe is the collection of all the objects in space and the space itself. The universe includes everything that our eye can see and even those things which we can't see. When we look at the sky on a dark clear night, we see the entire sky dotted with countless stars, some bright and some are not so sight. On observing these dotted stars, we find that many of them twinkle and some do not twinkle. These objects, which do not twinkle are the planets. The stars, the planets, the moon and everything that we see in the sky are called heavenly bodies.     Heavenly Bodies in the universe   The vast expanse of space that contains all the matters from the smallest particle to the planets, sun, moon, stars, asteroids and the biggest galaxy is called the universe. We do not exactly know how big our universe is. It is believed to be growing outward in every direction. Nobody really knows how the universe was formed. Most scientists believe that at first everything was solid heavy ball of matter. This ball exploded billions of years ago - and our universe was born. The explosion is called the big bang. How our universe was formed is still only a theory (an idea), astronomers continue to investigate the theory.           Stars and Planets            Stars The heavenly bodies which appear to twinkle in the sky are called the stars. A star is a huge ball of hot burning gases. It gives out heat, light and energy. The stars that appear as twinkling points of light in the night sky are very far away from us. Hence they appear to be very small. The greatest characteristic of star is that they have light of their own. Sun is the nearest star to us. Hence the sun appears to be so big and glowing. Without the sun's heat and light our earth would have been very cold. Life on earth would have not been possible. Sun is the ultimate source of energy for us. In a dark night sky we can see millions and millions of stars. To make it easy to identify stars, some have been grouped together to from shapes. These groups of stars are called Constellation. The shape of the constellation resemble familiar objects. To easily identify constellation, we should know what a particular constellation looks like and where to look for it in the night sky. Let us know about some constellations.          Ursa Major It is one of the most famous constellations, which can be seen during summer time in the early part of the night. It is also known as big dipper or great bear. more...

     Remedies of Pollution   The fight against pollution should be won at any cost because the survival of our planet is in danger. Pollution has started affecting the quality of our daily lives. We all need to realize our responsibility and work accordingly.           Reduce Pollution Burning of fossil fuel cause air pollution. We should reduce the use of such fuels and switch over to alternative fuels for our energy requirement like wind energy, solar energy, hydropower etc. We should say no to crackers and save the environment from its harmful releasing gases. The harmful chemical that pollutes water should not be directly disposed of into the rivers and lakes. There should be proper treatment of water in every factories, before the water is released into the rivers and lakes. We should follow the '3 R' rule very strictly. That is Reduce, Reuse and Recycle of natural resources. We should stop cutting of trees and should plant and nurture more trees and measures to conserve soil and wild life. Farmers should be encouraged to adopt safer ways of farming. They should use more of organic fertilizer. The use of chemicals pesticides and fertilizer should be discouraged. The plastic bags, one of the main cause of soil pollution, should be reduced or banned. As we all are responsible for the pollution and its effects, in the same way we all have a role to play in keeping our environment clean and healthy. We all should realize our responsibility in maintaining our natural resources in a healthy state. A lot can be done if we start to work together and from this day onwards.              Pollution can be checked by the use of: (a) CNG (b) LPG (c) Bio Gas (d) CFCs (e) A, B and C   Answer: (e)           What is meant by potable water? (a) Water used for watering the pots (b) Water suitable for drinking (c) Water in a pot (d) Water which can be carried from one place to another (e) None of the above   Answer: (b)     To produce each week's Sunday newspapers, 500,000 trees is to be cut down. The amount of wood and paper we throw away each year is enough to heat 50,000,000 homes for 20 years. Americans use 2,500,000 plastic bottles every hour. Plastic bags and other plastic garbage thrown into the ocean kill as many as 1,000,000 sea creatures every year! A modern glass bottle would take 4000 years or more to decompose — and even longer if it's in the landfill.     Environment: Environment is everything that make up the surrounding of living thing. Types of pollution: There are three major types more...