Std 10 English
Unit - 5 Playing With Fire
All spellings (Glossary)
Read the extracts and answer the questions.
(1) One of our favourite festivals in India is Deepavali or Diwali, as it is known in the North. There is nothing to match the excitement when crackers go off in the night sky with a loud bang and a brilliant shower of colours. Many of us might wonder how these fireworks are made, and what goes into them. The physics and chemistry of fireworks is as interesting as the sound and the light they emit.
1. Nothing can match the excitement....
Ans. Nothing can match the excitement when crackers go off in the night sky with a loud bang and a brilliant shower of colours.
2. The physics and chemistry of fireworks is as interesting as
Ans. The physics and chemistry of fireworks is as interesting as the
sound and the light they emit.
(2) The science of fireworks is technically called, 'pyrotechnics'- from the Greek word 'pyr' meaning fire and 'technics' meaning an art. Pyrotechnics includes not only fireworks but also a whole range of devices that use similar materials and principles, from safety matches that we use every day to solid fuel rocket boosters of the space shuttle. The household match is considered a special pyrotechnic device, as all the pyrotechnics effects-heat, smoke, light, gas and sound- are present in it.
What is pyrotechnics?
Ans. Pyrotechnics is a science of fireworks.
2. What does the word 'pyr' mean?
Ans. The word 'pyr' means fire.
3. What does pyrotechnics include ?
Ans. Pyrotechnics includes not only fireworks but also a whole range of devices that use similar materials and principles, from safety matches to solid fuel rocket boosters of the space shuttle.
4. Why is the household match a special pyrotechnic device?
Ans. The household match is a special pyrotechnic device because all the pyrotechnics effects-heat, smoke, light, gas and sound - are present in it.
5. Which are the different pyrotechnics effects in a household match?
Ans. The different pyrotechnics effects in a household match are: heat, smoke, light, gas and sound.
(3) Some historians say that 'black powder',
the basic material used in fireworks, was invented in India. Shukranti, written more than two thousand years ago, has references to weapons similar to guns and projectile weapons.
1. Which is the basic material used in
fireworks?
Ans. The basic material used in fireworks is black powder.
2. Shukranti has references to ....
Ans. Shukranti has references to weapons
similar to guns and projectile weapons.
(4) However, the Chinese are generally considered the pioneers of pyrotechnics. They are said to have developed, black up powder' more than one thousand years ago. It took at least two hundred years for the knowledge to spread to the west, and it was only in 1242 that an English. monk, Roger Bacon, revealed the formula for "black powder". He considered it such a dangerous substance that he wrote of it in a code language.
1. Who are said to be the pioneers of pyrotechnics ?
Ans. The Chinese are said to be the pioneers of pyrotechnics.
2. Who developed black powder? When? Ans. The Chinese developed black powder more than one thousand years ago.
3. Who revealed the formula for black powder? When?
Ans. Roger Bacon, an English monk, revealed the formula for black powder in 1242.
4. Why did Roger Bacon write about black powder in code language?
Ans. Roger Bacon wrote about black to from powder in code language because The considered it a very dangerous substance.
5. What was Roger Bacon's opinion about black powder?
Ans. According to Roger Bacon, black powder was a very dangerous substance.
(5) The basic formula of the black powder, or gun powder, has remained unchanged. for centuries. It is a blend of potassium nitrate, charcoal and sulphur in the ratio of 75:15:10 by weight. It is almost the perfect combination as it is and no further improvements or alternations need be made. Experts say that this might be the only chemical product still using the same age old proportions and manufacturing techniques.
1. has remained unchanged for centuries. Ans. The basic formula of black powder has remained unchanged for centuries.
2. What is the formula for black powder? Ans. Black powder is a blend of potassium nitrate, charcoal and sulphur in the ratio of 75:15:10 by weight.
3. What do the experts say about the formula of black powder ?
Ans. Experts say that black powder might be the only chemical product still using the same age old proportions and manufacturing techniques.
(6) However, with the development of modem chemistry, light and colour effects have become common in fireworks. In the last century, the discovery of aluminium, magnesium and titanium, which burn at high temperatures emitting bright light dramatically improved the brilliance of fireworks. Similarly, colours too are a recent development. The principal colour emitters in pyrotechnics were identified after decades of research. These colours are formed in one of two ways luminescence and incandescence.
1. What is the result of the development of modern chemistry?
Ans. As a result of the development of modern chemistry, light and colour effect have become common in fireworks.
2. What has improved the brilliance of fireworks?
Ans. The discovery of aluminium, magnesium and titanium, which burn at high temperatures emitting bright light has improved the brilliance of fireworks.
3........... were identified after decades of research.
Ans. The principal colour emitters in pyrotechnics were identified after decades of research.
4. Name the two ways in which colours are formed?
Ans. Colours are formed in one of two
ways luminescence and incandescence.
(7) Incandescent light is produced when a substance is heated so much that it begins to glow. Heat causes the substance bally to become hot and glow, initially emitting war infra red, then red, orange, yellow and white light as it becomes increasingly hotter. When the temperature of a firework is controlled, the glow of its Grmometallic substances can be manipulated to be a desired colour at the proper time.
1. How is Incandescence light produced? Ans. Incandescent light is produced when a substance is heated so much that it begins to glow.
2. When the substance becomes hot, initially it emits............
Ans. When the substance becomes hot, initially it emits infra red light.
3. When the substance becomes 29 increasingly hotter, it emits ..........
Ans. When the substance becomes increasingly hotter, it emits white light.
4. Why is the temperature of a firework controlled?
Ans. The temperature of a firework is controlled so that the glow of its metallic substances can be manipulated to be a desired colour at the proper time.
(8) The principle behind any firework is that when heat is applied to fuel (the gun powder), it burns using oxygen. However, because the fuel is packed tightly to keep the heat in, the burning takes place all of a sudden and it causes the characteristic loud noise. The actual manufacturing process of firework is simple. The raw materials required are fuel, binders, oxidisers (to make it burn), and a few other materials. The ingredients are ground and mixed well, the mixture. is pushed through a machine from which it comes out as long rolls or strips, and then rolled in cardboard or old newspapers with a fuse.
1. What is the principle behind any firework?
Ans. The principle behind any firework is that when heat is applied to the gun powder, it burns using oxygen.
2. What happens when the fuel is packed tightly?
Ans. When the fuel is packed tightly, the heat is kept in and the burning takes place all of a sudden and it causes the characteristic loud noise.
3. Which raw material are required to manufacture fireworks?
Ans. The raw materials required to manufacture fireworks are fuel, binders, oxidisers and a few other materials.
4. How are fireworks manufactured?
Ans. The ingredients are ground, mixed well, pushed through a machine from which it comes out as long rolls or strips, and then rolled in cardboard or old newspapers with a fuse.
9) The greatest danger of pyrotechnics is that it deals with fire. The industry is notorious for its accidents, whether in the U.S.A., Japan or India. Though the mixture is stable if kept cool and dry, it can catch fire if heat is accidently applied, through too much friction sometimes, or from a spark or an impact. Scientists are looking for ways of making fireworks safer.
1. What is the greatest danger pyrotechnics?
Ans. The greatest danger of pyrotechnics
is that it deals with fire.
2. What are the dangers of pyrotechnics ?
Ans. The mixture is stable if kept cool and dry, but it can catch fire if heat is accidently applied, through too much friction, or from a spark or an impact.
(10) In India, fireworks used to Le imported from China. During the Second World War, these imports were stopped, and the safety match producers of Sivakasi in Tamil Nadu began manufacturing fireworks for Deepavali. In 1992, the country used about 60 crores worth of firework and 60 to 70 per cent of this came from Sivakasi.
1. From which country were fireworks imported?
Ans. Fireworks were imported from China.
2. When was the import of fireworks
stopped?
Ans. The import of fireworks was stopped during the Second World War.
3. Who started manufacturing fireworks in India?
Ans. The safety match producers of
Sivakasi in Tamil Nadu began manufacturing fireworks in India.
4. About..... came from Sivakasi.
Ans. About 60 to 70 per cent of fireworks
in the country came from Sivakasi.
(11) In Sivakasi, fireworks are manufactured in a number of small units. Three months before the festival is the busiest time for these units. Fireworks are transported to every nook and corner of the country. The working conditions of these units are however far from satisfactory. There are very few testing facilities for quality bor uniformity, and hardly any safety measures in force. This is why we hear of accidents in Sivakasi year after year. It is very difficult to get information on w how to manufacture fireworks because it is not considered safe to give everybody the details. Only a very few reliable 10 persons are taught this art.
1. Why do fire accidents take place in Sivakasi?
Ans. Fire accidents take place in Sivakasi because there are hardly any safety. measures in force there and there are very few testing facilities for quality or uniformity.
2. Why are only a few reliable persons. taught the art of manufacturing fireworks?
Ans. Only a few reliable persons are taught
the art of manufacturing fireworks because it is not considered safe to give everybody the details.
3. In Sivakasi, fireworks are manufactured in ...
Ans. In Sivakasi, fireworks are manufactured in a number of small units.
4. Which is the busiest time for the units? Ans. Three months before the festival of Diwali is the busiest time for the units.
(12) In many countries, fireworks are not allowed to be used by individuals. Only community displays, specially organized with the help of experts, are allowed. A great deal of care is taken for safety at these displays. However, since even children are allowed to play with fireworks in India, it is important to observe certain safety rules.
1. In many countries, are allowed.
Ans. In many countries, only community displays, specially organized with the help of experts, are allowed.
2. Why should we observe safety rules in India?
Ans. We should observe safety rules in
India because even children are allowed to play with fireworks.
(13) Fireworks should be stored, handled and lit with care. They should never be stored or unpacked near a flame, gas cylinder or heater. One should never wear long, loose clothes or nylon clothes when lighting crackers. And since the powder in crackers is poisonous, they should never be carried loose in your pocket or your hand. Also, fireworks should never ever be lit inside a house, Never bend over a firework when you are lighting it and never use fireworks to frighten people. If in spite of being careful, you do get a burn, go to a doctor instead of applying oil or ointment.
1. Fireworks should be..... with care.
Ans. Fireworks should be stored, handled and lit with care.
2. What care should be taken to store and unpack fireworks?
Ans. Fireworks should never be stored o unpacked near a flame, gas cylinder or heater.
3. What kind of clothes should we not wear while lighting fireworks?
Ans. While lighting fireworks, we should not wear long, loose or nylon clothes.
4. Why should we not carry crackers in our hand?
Ans. We should not carry crackers in our hand because the powder in them is poisonous.
5. What care should we take while lighting fireworks?
Ans. Fireworks should never be lit inside a house and we should never bend over a firework when we are lighting it.
6. If you do get a burn,....
Ans. If you do get a burn, go to a Sum doctor instead of applying oil or ointment.
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