Table of Contents
Chapter - 8 Fire: Friend and Foe
MCQs
Question 1.
When the energy is released in the form of heat and light, it is:
(a) fire
(b) a chemical reaction
(c) light energy
(d) both (a) and (b)
Answer
(d) both (a) and (b)
Question 2.
Lowering the temperature below the flash point:
(a) causes fire
(b) extinguishes the fire
(c) lowers the density
(d) none of the above
Answer
(b) extinguishes the fire
Question 3.
Man’s first experience of fire could be:
(a) lightning
(b) rubbing stones
(c) volcanoes
(d) both (b) and (c)
Answer
(d) both (b) and (c)
Question 4.
When carbon and hydrogen are combined with oxygen, they:
(a) can cause fire
(b) can cease fire
(c) explode
(d) none of the above
Answer
(a) can cause fire
Question 5.
The temperature at which every fuel bums is called:
(a) the flush point
(b) the flash point
(c) the fire point
(d) all the above
Answer
(b) the flash point
Question 6.
Fire can be:
(a) a good servant
(b) created
(c) a bad master
(d) both (a) and (c)
Answer
(d) both (a) and (c)
Question 7.
Fire brigade is:
(a) an old concept
(b) a band of fire-fighters
(c) a human chain
(d) both (a) and (b)
Answer
(b) a band of fire-fighters
Question 8.
The fuels available in natural form are:
(a) cooking gas
(b) electricity
(c) petrol
(d) coal
Answer
(d) coal
Question 9.
Fire is our
(a) friend
(b) foe
(c) neither friend nor foe
(d) both a friend and foe
Answer
(d) both a friend and foe
Question 10.
Fire is a bad master if it is
(a) made by coal
(b) made by electricity
(c) under
(d) uncontrolled
Answer
(d) uncontrolled
Question 11.
Early man might have experienced fire by
(a) Watching lighting and volcanoes
(b) watching fire files
(c) keeping it under wraps
(d) none of these
Answer
Answer: (a) Watching lighting and volcanoes
Question 12.
___ is released in the form of heat and light.
(a) carbon
(b) hydrogen
(c) light
(d) energy
Answer
Answer: (d) energy
Question 13.
There things required to make fire are
(a) fuel
(b) heat
(c) oxygen
(d) all of these
Answer
Answer: (d) all of these
Question 14.
The ‘flash point’ of fuel is
(a) torch light
(b) temperature to bum
(c) memory
(d) lighting match
Answer
Answer: (c) memory
Question 15.
If the fire has no fuel to feed on, preventing oxygen supply and removing the heat can lead to
(a) put out fire
(b) break out epidermic
(c) start a fire
(d) cook our food
Answer
Answer: (a) put out fire
Question 16.
Water should not be used on fire caused by
(a) fuel
(b) dry leaves
(c) oil
(d) electrical appliances
Answer
Answer: (d) electrical appliances
Question 1.
What is early man’s outlook for fire?
Answer:
He was scared of fire. The early man might have seen volcanoes or lighting before he started using fire and was hence knew it was dangerous and powerful.
Question 2.
Give some examples of fuel.
Answer:
Wood, coal, cooking gas and petrol are examples of fuel.
Question 3.
Why gaps are left between buildings during construction?
Answer:
Gaps are left between buildings during construction to reduce the risk of fire.
Question 4.
How has the discovery of fire helped the mankind?
Answer:
Discovery of fire has helped the early man to cope with nature. It also helped them adopt a settle mode of life.
Question 5.
How fire is a good servant?
Answer:
Fire is a good servant. When kept under control fire helps us do many things in most of our home we cook our food on fire. We use fire to keep us warm during extreme winter. It is also used to generating electricity.
Question 6.
Before fire brigades were set out, how people tried to put out fire.
Answer:
Before the fire brigade came into the picture people used to extinguish fire forming human chain. Everyone was a fireman in that scenario. People used to pass buckets filled with water from a pond or well through each other and the person at the extreme end used to pour it over the flames.
Question 7.
How have we learnt to control fire?
Answer:
Every year we spend millions of rupees for fighting fires. We spend even large sum of money to find out ways to prevent fire from happening and going out control in the process we have learnt to control fire and use it for our betterment.
Question 8.
Explain with an example how can you put out fire by cutting the supply of oxygen.
Answer:
Oxygen is one of the three elements essential for causing fire. If we can disrupt the supply of oxygen then we can put of the fire. This can be applied in case of small fires. If we throw a damp blanket or a sack over fire. It cuts off the supply of oxygen and the fire is immediately put off.
Question 9.
Why we cannot use water to put out some fires?
Answer:
We cannot use water in case of oil and electric fires oil floats over water and thus oil fires cannot be extinguished using water. Water flows on and it has the risk of spreading the fire along. In case of electric fires water cannot be used as an extinguished. It being a good conductor of electricity puts the life of the man spraying it in danger.
Question 10.
What is the role of fire fighter?
Answer:
Fire fighters are given training on various skills to minimize the damage. They put out fire and also give first aid.
Question 11.
What do you understand by the ‘flash point’ of a fuel?
Answer:
The temperature at which a fuel begins to burns is called its flash point.
Question 12.
(i) What are some common uses of fire?
(ii) In what sense is it a “bad master”?
Answer:
(i) The common uses of fire are to cook food, warm our names in winter, to generate electricity and many more.
(ii) If fire goes out of control, it can cause damage to our life, house and property. It is ‘bad master’ in this sense.
Fire: Friend and Foe Extra Questions and Answers Long Answer Type
Question 1.
What is your opinion about fire after ready the lesson?
Answer:
As the title of the lesson suggests fire is both/riled and foe. It can be dangerous and threat to life and property. Valuable resources get engulfed by the fire. So various measures and laws are enforced to save lives and resources.
Question 2.
‘Power needs control’ Do you agree or not. Give you response in reference to the text.
Answer:
Every powerful things or person can be controlled and checked from time to time. For example, fire is so useful in day to day life that human existence is impossible without fire yet it can destroy in records. So its power should be checked before getting out of control. Establishment like fire brigade are so helpful. Vigilance and alertness can stop from a turning of a friend into a foe.
Question 3.
What are the three main ways in which a fire can be controlled or put out?
Answer:
The three main ways in which a fire can be controlled or put out are:
(i) By taking away the fuel. If the fire has no fuel to feed on. No burning can take place.
(ii) By preventing oxygen from reaching it.
(iii) By bringing back the temperature below ‘flash point’ of the fuel.
Question 4.
Why does a burning candle go out when you blow on it?
Ans.
When we blow on candle, the hot air around the candle gets removed and it burning down the temperature of candle below the flash point. Thus, a candle goes out because no fuel can bum below its flash point.
Question 5.
Spraying water is not a good way of putting out an oil fire or an electrical fire. Why not?
Answer:
If water is sprayed onto an oil fire, then the oil will float to the top of the water and continue to bum. This can be very dangerous because water can flow quickly. Carrying spray water might receive an electric shock and be killed. Therefore, spraying water is not a good way of putting out an oil fire or an electrical fire.
Question 8.
What are some of the things you should do to prevent a fire at home and in the school?
Answer:
Some of the things we should do to prevent a fire at home and in the school:
(i) Precaution is better than cure. We should be alert about the use of inflammable substances and handle it with care.
(ii) There is always possibility of catching fire in old buildings of home and school due to short circuits. Therefore, over loaded wired should be replaced with new ones and Fuse should be checked at regular interval.
(iii) By spreading in knowledge about the handling of fuel, its flash point and about its protection after an accident.
(iv) Fire extinguisher should be installed and old wiring must be replaced. Keeping the contact number of fire police on speed dial in case if little accident may happen.
(v) Never taking the little accident of fire lightly as it may lead to greater one and finding a way out so that it may not happen in future. Not storing inflammable or combustible things like kerosene and petrol in our homes and in the school.
Fire: Friend and Foe Extra Questions and Answers Reference to Context
Question 1.
He must have watched lightning and volcanoes long before he began to use fire himself. Fire was powerful and dangerous, and he was frightened. Fire may have puzzled early man but we now know that fire is the result of a chemical reaction. When the oxygen in the air combines with carbon and hydrogen in a fuel, a chemical reaction takes place. Energy in the form of heat and light is released in this process. This is what we call fire.
Questions
(i) Who must have watched lightning?
(ii) Why was ‘he’ afraid of fire?
(iii) What is the chemical reaction in fire?
(iv) What is released from fire?
(v) Choose from the passage an adjective with the meaning ‘perplexed’.
Answer:
(i) Early man must have watched lightning.
(ii) He was afraid of fire because it was powerful and dangerous.
(iii) When the oxygen in the air combines with carbon and hydrogen in a fuel, a chemical reaction takes place.
(iv) Energy is released in the form of heat and light.
(v) Puzzled.
Question 2.
It is sometimes said that fire is a good servant but a bad master. It only means that fire is very useful as long as it is kept under control. For instance, we use it to cook our food, warm our homes in winter and to generate electricity. But, on the other hand, if fire gets out of control it can be very dangerous. Each year thousands of homes and shops are damaged by fire. Vast areas of forest are also destroyed and hundreds of people are killed or injured.
(i) Who is called as ‘a bad master’?
(ii) Where do we use fire?
(iii) Why are the forest destroyed?
(iv) Give examples of fire as ‘a bad master’.
Answer:
(i) Fire is called as ‘a bad master’.
(ii) It is used to cook food, warm homes in winters and to generate electricity.
(iii) According to the writer, the forest is destroyed by uncontrolled fire.
(iv) Every year thousands of homes and shops are damaged by fire. Human lives and forests are badly affected by its impacts of fire.
Question 3.
The third way of putting out a fire is to remove the heat. If the temperature can be brought down below the flash point, the fuel stops burning. You blow on a burning matchstick or a candle to put it out. In doing so, you remove the hot air around the flame bringing down its temperature below the flash point, and the candle goes out. Sometimes, water is sprayed on a fire. It absorbs heat from the burning fuel and lowers the temperature. The blanket of water also cut off the supply of oxygen, and the fire is extinguished.
(i) How can fire be put out?
(ii) When does the fuel stop burning?
(iii) What is the impact of water if sprayed on a fire?
(iv) How can fire is extinguished with \frater?
(v) Give the meaning of ‘extinguished’.
Answer:
(i) Fire can be put out by removing the heat.
(ii) If Hie temperature can be brought down below the flash point the fuel stops burning.
(iii) It absorbs heat from the burning fuel and lower the temperature.
(iv) The blanket of water cuts off the supply of oxygen, and the fire is extinguished.
(v) Put out.
Question 4.
Long ago, there were no firemen. When fire broke out, everybody became a firefighter. People formed human chains (they still do if required) and passed buckets of water from a well or a pond to the blaze. Now there are laws about building construction which ensure that space is left between buildings to reduce the fire risk. Every new building, especially a public place, must ensure observance of fire prevention norms. Bands of fire fighting workers with special equipment, known as fire brigades, are there to put out fires. Firefighters are highly trained people. They possess many skills. They cut off electricity supply, knock down dangerous walls, spray water and other materials to bring fire under control.
(i) What happened in earlier times when fire broke out?
(ii) Why are the laws about building construction enforced?
(iii) What is a fire brigade?
(iv) What are the skills of fire fighters?
(v) Change verb ‘Prevent’ into a noun.
Answer:
(i) When fire broke out, everybody became a fire – fighter by forming human chains.
(ii) There are laws about building construction to reduce the fire risks.
(iii) Fire brigade is a band of fire fighting workers with special equipment.
(iv) Fire fighters are highly trained people. They cut off electricity supply, knock down dangerous walls spray water and other materials to bring fire under control.
(v) Prevention.