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Posts tagged "Science Facts" (Page 47)
What is a Queen Bee? You must have heard of the expression ‘queen bee’ describing someone who does lots of work in a community and enjoys being the centre of attention. This aptly describes the role of the queen bee in a hive of honey bees. Honey bees, like ants, are social insects, and long ago man found that they were quite happy to live as a colony in a wooden...
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September 19, 2017 evirtualguru_ajaygourParagraph WritingNo Comment
How widespread is the use of Television? Television is used in many industries. Banks and stores use ‘closed-circuit’ TV for security. Undersea oil-wells use remote-controlled cameras to check pipelines. Nuclear power stations use TV to watch dangerous areas. But its most widespread use is broadcasting the programmes we watch at home. TV brings us entertainment, news and advertisements. Once people had to amuse themselves or go to a local theatre....
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September 19, 2017 evirtualguru_ajaygourParagraph WritingNo Comment
What is an outside broadcast? Of course, if we want to make a programme about an earthquake, or even a city street, we cannot bring this inside the studio. Instead we take the studio outside. The ‘outside broadcast’ teams use a specially-equipped van as a mobile control-room. They have smaller, movable cameras and microphones. There are even video-tape cameras, for making TV recordings, not much bigger than home-movie cameras. In...
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September 19, 2017 evirtualguru_ajaygourParagraph WritingNo Comment
How is a Television programme made? The picture below shows a pop group making a television programme. As well as the performers a lot of other people with a lot of equipment are needed to produce a programme. The three cameramen operate the TV cameras. Each can take a picture of the whole scene or a close-up, perhaps of just the singer’s face. Using a special lens the camera can even...
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September 19, 2017 evirtualguru_ajaygourParagraph WritingNo Comment
How does your Television set make a picture? The television receiver does the opposite of what the camera did. On your TV screen is a chemical that glows when electrons hit it. An electron beam moves across the screen exactly in step with the beam in the camera. The current sent from the camera controls the strength of the beam. A strong beam gives a bright spot, a weak beam a...
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September 19, 2017 evirtualguru_ajaygourParagraph WritingNo Comment
When was Television invented? John L. Baird of Scotland made the first simple television soon after the first world war. Public TV started in 1936 in Britain. How does a television camera work ? A TV camera has to convert a whole picture into an electric current. First of all a picture, called an ‘image’, of the scene in front of the camera is focused onto a screen inside. A...
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September 19, 2017 evirtualguru_ajaygourParagraph WritingNo Comment
What are Radio Waves? Radio waves are like light except that we cannot see them with our eyes and they are harder to stop. They can go through walls, for example. In fact, light and radio waves are both examples of ‘electromagnetic radiation’. Like light, radio waves travel 300,000 km (I 86,000 miles) each second and go in straight lines unless blocked (by something like thick concrete) or reflected. Because...
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September 19, 2017 evirtualguru_ajaygourParagraph WritingNo Comment
How are Radio messages sent and received? The sender speaks into a microphone which converts the sound of his voice into an electric current. A transmitter first makes this current stronger then feeds it to an aerial which sends out radio waves. This aerial is a long wire, often as tall as a high building. When radio waves hit another aerial, like the one on your radio set, they are picked...
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September 19, 2017 evirtualguru_ajaygourParagraph WritingNo Comment
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