Fire: Friend and Foe Class 7 English Honeycomb Book Chapter 8 Explanation, Question Answer



Fire: Friend and Foe Class 7 English Honeycomb Book Chapter 8 Explanation

NCERT Solution for Class 7 English Honeycomb Book Chapter 8 Fire: Friend and Foe Summary, Explanation, Question Answer

Fire: Friend and Foe – NCERT Class 7 English Honeycomb book Lesson 8 -Detailed explanation of the lesson along with the meanings of difficult words. Also, the explanation is followed by a Summary of the lesson. All the exercises and Questions and Answers given at the back of the lesson have been covered. Take Free Online MCQs Test for Class 7 Click Here


Class 7 English (Honeycomb book) Chapter 8 Fire: Friend and Foe

 

Fire: Friend and Foe  IntroductionFire: Friend and Foe Video Explanation
Fire: Friend and Foe SummaryFire: Friend and Foe Lesson Explanation
Fire: Friend and Foe Question Answers 

 

 

Fire: Friend and Foe  Introduction

We all know that fire can be both dangerous and useful. In this chapter, we will learn what fire really is and how it can be both dangerous and useful to us. We will learn about the discovery of fire and who discovered it. Also, we need to know how to control fire so that it can’t harm us.
 

 

 

Fire: Friend and Foe Class 7 Video Explanation

 


 

 

 

Fire: Friend and Foe  Summary

Early man didn’t know what fire was. However, they must have seen the damage caused by the bolts of lightning and the volcano eruptions. Since he didn’t know what fire was and hadn’t discovered the uses of it, he was frightened by the damage caused by this unknown thing. Then the writer tells us that fire had confused the early man, but we now know what fire is. Fire is the result of a chemical reaction. When oxygen gas reacts with hydrogen and carbon in the form of a fuel, energy is released in the form of heat and light. This is known as fire. Hence, we know that three things are required for the making of fire – heat, fuel and oxygen. Fuel can be in the form of petrol, wood, coal or cooking gas. Oxygen can be found in free air. Hence, the requirement of oxygen can be met quite easily. For example, when we blow on a smouldering piece of paper, the paper catches fire. The last requirement is heat. If heat would not have been a requirement, then a newspaper lying anywhere could also burst into flames. To make the wood catch fire, we heat it. This is often done with a lighted matchstick. Now, we have to wait for some time for the wood to catch fire. This is because every fuel has a particular temperature at which it begins to burn. So, we have to wait for the wood to reach that particular temperature, and that temperature would be wood’s ‘flash point’ or ‘kindling temperature’. Then, the writer tells us that it is sometimes said that fire is a good servant but a bad master. It means that fire is useful only when it is kept under control. The writer then takes an example of fire being useful for cooking, keeping us warm in winters and generating electricity until it goes out of control and burns down our house. Each year thousands of homes and shops are damaged by fire due to this reason. Vast areas of forest are also destroyed and hundreds of people are killed or injured. Then, the writer tells us that the number of ways to put out fire are also three. In each way, one of the requirements is  taken from the fire, which extinguishes it. The first way is to take away the fuel. By taking away the fuel, fire will not have a substance to burn on, so it will get extinguished. The second way of putting out a fire is to prevent oxygen from reaching it. If we block oxygen and prevent it from reaching the burning substance, it will eventually extinguish the fire. Oxygen is a gas which supports burning. No supply of oxygen means no fire. 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. To do so, we usually use water. However, not all fires can be brought down with buckets of water. Such fires are the fires caused by oil and electric appliances. If we use water onto an oil fire, the oil fire will float on the water because of the oil in it. In fact, the water can spread the oil fire even more, which will result in more damage. If a person tries to put out an electric fire with water, the person will receive an electric shock, which can even kill the person. The correct way is to use fire extinguishers which have carbon dioxide. The writer then tells us that we spend millions of rupees each year in fighting fires. Also, we spend millions of rupees each year to find new ways of preventing fires from happening and also keeping them under control. Because of this, we have found good ways to control fire and put it to good use in our everyday life. The writer then tells us about the olden times, when there were no firemen. People themselves were firemen. They would form a human chain which would start from the burning building to a well or a pond. With buckets, the water would get transported from one person to another then onto the fire. However, things have changed. Now there are laws about building construction which ensure that space is left between buildings to reduce the risk of spreading of fire. Every new building, especially a public place, must ensure observance of fire prevention norms. Bands of firefighting workers with special equipment, known as fire brigades, are there to put out fires. Firefighters are highly skilled  and brave people. They possess many skills. They cut off electricity supply, knock down dangerous walls, spray water and other materials to bring fire under control. Also, they are trained in providing First Aid so that they can help the injured people. The discovery of fire and its uses have been very useful for the settled mode of life. Fire is worshipped in some places, who believe that worshipping fire will keep them safe. We should never forget: fire is a friend but a foe when gone out of control.
 

 

 

Fire: Friend and Foe Explanation

Early man didn’t know what fire was, but he must have seen the damage it could cause. He must have watched lightning and volcanoes long before he began to use fire himself. Fire was powerful and dangerous, and he was frightened.
The writer talks about the time when early man had not discovered fire but had seen the damage caused by it through bolts of lightning and volcanic eruptions. Since he didn’t know what was causing such damage, he was afraid of fire, which was powerful and dangerous.

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.
puzzled: confused
released: given out

Fire had confused the early men but nowadays, we humans know what fire is. Fire is the result of a chemical reaction. In this chemical reaction, oxygen gas is combined with carbon and hydrogen in a fuel, energy is released in the form of heat and light which is what we call fire.

Three things are needed to make fire— fuel, oxygen and heat. Wood, coal, cooking gas and petrol are some examples of fuel. Oxygen comes from the air. That is why, when you blow on smouldering paper, it often bursts into flame. The third thing needed to make fire is heat. Fuel and oxygen do not make fire by themselves, or else a newspaper or a stick lying in the open would catch fire on its own. To burn a piece of paper or wood, we heat it before it catches fire. We generally do it with a lighted match. Every fuel has a particular temperature at which it begins to burn. This temperature is called the ‘flash point’ or ‘kindling temperature’ of the fuel.
smouldering: burning slowly without flame
Then, we get to know about the things required to make a fire. There are three things needed to do so, and those things are – fuel, oxygen and heat. Fuel is something which is required to catch fire, like wood, coal, cooking gas and petrol. Then comes oxygen gas, which can be found in air. We can prove this by blowing on a smouldering paper. When we blow, oxygen blows into the smouldering paper, which makes it burst into flames. The third and final requirement is heat. Fuel and oxygen cannot make a fire by themselves. If that would have been the case, then any newspaper or stick lying in the open would have caught fire. To burn a substance, we have to heat it. We usually do this step by a lighted match. Then, we have to wait for the thing to reach its flash point or kindling temperature, which is the temperature at which a fuel starts burning. Every fuel has its own flash point. For example – paper and wood will have different kindling temperatures, meaning that paper will catch fire sooner than wood.

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.
generate: produce
Then, the writer tells us the meaning of the popular saying: fire is a good servant but a bad master. It has only one meaning – that fire is useful only when it is under our control. When it goes out of control, a lot of irreparable damage is caused.
For example, fire is useful for cooking our food, keeping our homes warm in winter and for generating electricity because during that time it is under our control. But when it goes out of control, it can burn down our house and injure us too. Then the writer tells us that each year, thousands of homes and shops are damaged by fire and vast areas of forest are also destroyed by forest fires. During that time, hundreds of people are killed or injured.

Just as three things are needed to start a fire, there are three main ways in which a fire can be put out. In each, one of the three things needed for burning is taken away.
For example, we can take away the fuel. If the fire has no fuel to feed on, no burning can take place. We often let a fire die out simply by not adding more fuel to it.
add fuel to the flames (idiom): say or do something that makes people react more strongly and fiercely
Now the writer tells us the ways in which we can put out a fire. Just as three things are needed to start a fire, we have three ways in which we can successfully put out a fire. In each way, one of the requirements of burning is taken away.
The first way is to take away the fuel. If the fire would not have something to feed on, the fire would ultimately get extinguished. We often let a fire die out by not adding fuel to it.

The second way of putting out a fire is to prevent oxygen from reaching it. No supply of oxygen means no fire. Small fires can be put out or ‘smothered’ with a damp blanket or a sack. This stops oxygen reaching the burning material. Sometimes, carbon dioxide is used to extinguish fire. It does not allow oxygen to reach the burning material.
smothered: suffocated (from lack of air)
damp: slightly wet
extinguish: put out

The second way of extinguishing a fire is to cut the supply of oxygen from reaching the burning substance. A fire cannot burn without oxygen. No supply of oxygen means no fire. Small fires can be put out with a damp blanket or a sack. Here, the word ‘smothered’ means that a damp blanket or a sack can cut off the supply of oxygen in the same way as a damp blanket or a sack can cut off the supply of oxygen to humans and can suffocate them. Then, instead of taking away oxygen, we can add the supply of carbon dioxide, which will extinguish the fire. Carbon dioxide will form a blanket around the fire which will prevent oxygen from reaching the burning fuel.

 

 

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 cuts off the supply of oxygen, and the fire is extinguished.
The third and the final way of putting out a fire is to remove the heat. If we can lower the temperature to such an extent that it comes below the flash point, the fuel will gradually stop burning. For example – we blow on a burning matchstick or a candle to remove the hot air around the flame so that the temperature comes below the flash point and the candle gets extinguished. Another way of removing heat is to spray water on the fire. The water absorbs heat from the burning fuel and lowers the temperature. The water, just like carbon dioxide, forms a blanket around the fire and cuts off the supply of oxygen, which extinguishes the fire.

Some fires cannot be put out with water. If water is sprayed onto an oil fire, the oil will float to the top of the water and continue to burn. This can be very dangerous because water can flow quickly, carrying the burning oil with it and spreading the fire. Water should also not be used on fires caused by electrical appliances. The person spraying water might receive an electric shock and be killed. A carbon dioxide extinguisher is the best thing to fight an electrical fire.
There are some fires which cannot be put out with water. There are two types of such fires – oil and electrical. If we spray water onto an oil fire, the oil will float on the water which will not prevent it from burning but will carry the burning oil and spread the fire more. If we spray water on an electrical fire, the person who is spraying the water will receive an electric shock which can kill the person too. For these two types of fires, we should use a carbon dioxide extinguisher.

We spend millions of rupees each year in fighting fires. And we spend more trying to find new ways of preventing fires from happening and getting out of control. On the whole, we have learnt rather well to control fire and put it to good use in our everyday life.
The writer tells us that we humans spend millions of rupees each year just for one purpose – to fight fires. Not only that but we spend a lot more to find new ways of preventing fires from happening and getting out of control. We spend millions of rupees to find new scientific ways of controlling fire. All this has led to the rise of numerous ways by which we can control fire and put it to good use in our everyday life.

 

fire friend and foe

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 firefighting 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. They are also trained in first aid so that they can help people suffering from burns or from the effects of smoke.
blaze: intensely burning fire
bands: groups
equipment: things needed

During the olden times, there were no firemen. When fire broke out, people didn’t call for the firemen. Instead, they would help themselves by becoming firefighters. People formed human chains and this method is still in use. The human chain would start from the burning building to a well or a pond. With buckets, the water would get transported from one person to another then onto the fire. However, things are now different than before. Now there are special rules made just to prevent fires from happening and spreading. First is that there should be space left between buildings to reduce the spread of fire from one building to another. Next, every new building, especially a public place, must ensure observance of fire prevention norms. Last, if there is a fire, then fire brigades, which are bands of firefighting workers with special equipment, will be there to put the fire out. Firefighters are highly trained and skilled people. They can do five things – cut off electricity supply, knock down dangerous walls, spray water, bring fire under control and give first aid to the people who are suffering from burns or from the effects of smoke.

The discovery of fire and its uses helped early man to cope with nature better and gradually adopt a settled mode of life. Fire is still worshipped in many parts of the world. Fire is indeed a friend but, as we know, it can be a dangerous enemy once it gets out of control.
cope: deal with; manage
gradually: slowly, eventually, finally

The discovery of fire and its various uses had helped early man to cope with nature better. Moreover, it was due to fire that we were able to adopt a settled mode of life. Fire is still worshipped in many parts of the world because people are grateful for its help and also scared of the damage it can cause. Fire is a friend of ours, but it turns into a dangerous enemy if it gets out of control.
 

 

 

Fire: Friend and Foe – Question and Answers

 
 
Fire: Friend and Foe – Comprehension Check
Q1. Mark the correct answer in each of the following.
(i) Early man was frightened of
(a) lightning and volcanoes.
(b) the damage caused by them.
(c) fire.
(ii) (a) Fire is energy.
(b) Fire is heat and light.
(c) Fire is the result of a chemical reaction.
Ans. (i) (c) fire.
(ii) (c) Fire is the result of a chemical reaction.

Q2. From the boxes given below choose the one with the correct order of the following sentences.
(i) That is fire.
(ii) A chemical reaction takes place.
(iii) Energy in the form of heat and light is released.
(iv) Oxygen combines with carbon and hydrogen.

Ans.

 
Working with the Text
Q1. What do you understand by the ‘flash point’ of a fuel?
Ans. The temperature at which a fuel starts burning is called the ‘flash point’ of a fuel. It is also called ‘kindling temperature’.

Q2. (i) What are some common uses of fire?
(ii) In what sense is it a “bad master”?
Ans. (i) Some common uses of fire are – cooking food, keeping our homes warm in winters, generating electricity, erasing darkness.
(ii) Fire is a ‘bad master’. A master does not obey others. In the same way, when fire goes out of control, it doesn’t listen to us anymore which is why it is called ‘master’. Now when it does this, it damages humans and the surroundings. That is why fire is called a “bad master”.

Q3. Match items in Column A with those in Column B.

 

Ans. (i) fuel

  1. coal
  2. wood
  3. cooking gas

(ii) oxygen

  1. air

(iii) heat

  1. lighted matchstick
  2. burning coal
  3. smoldering paper

Q4. What are the three main ways in which a fire can be controlled or put out?
Ans. There are three main ways in which a fire can be controlled or put out. In each way, one of the three things required to make a fire ( fuel, oxygen and heat ) is taken away. In the first way, the fuel is removed so that the fire won’t have something to burn on which will eventually extinguish. The second way is to cut the supply of oxygen so that it doesn’t reach the burning substance. No oxygen means no fire. The last and the final way is to remove the heat. For this we have to lower the temperature of the fuel to such an extent that the temperature becomes lower than the flash point of that particular fuel. We can use either water or a carbon dioxide extinguisher for this.

Q5. Match the items in Box A with those in Box B

Ans. (i) To burn paper or a piece of wood, – we heat it before it catches fire.
(ii) Small fires can be put out – with a damp blanket.
(iii) When water is spread on fire, – it absorbs heat from the burning material and lowers the temperature.
(iv) A carbon dioxide extinguisher is the best thing – to put out an electrical fire.
(v) Space left between buildings – reduces the risk of fire.

Q6. Why does a burning candle go out when you blow on it?
Ans. A burning candle goes out when we blow on it because as we blow air, the hot air which is around the flame gets removed and a blanket of carbon dioxide gets formed around the flame which prevents oxygen from reaching the fire.

Q7. Spraying water is not a good way of putting out an oil fire or an electrical fire. Why not?
Ans. Spraying water is not a good way of putting out an oil fire or an electrical fire. If we spray water on an oil fire, the oil will just float upon the water. Moreover, the water will carry the oil fire and spread it more. If we spray water onto an electrical fire, the person doing so will receive an electric shock.

Q8. What are some of the things you should do to prevent a fire at home and in the school?
Ans. The measures to prevent a fire at home and in the school are as follows :

  1. Don’t wear synthetic clothes while cooking food.
  2. We should fit smoke alarms and fire extinguishers at our homes and in our schools.
  3. We should not leave our gas-stoves unattended.
  4. Non-cooking equipment such as plastic, towel etc must be kept away from the gas-stove.
  5. We should not store inflammable things like kerosene and petrol at our homes and in the schools.
  6. We should create awareness among the people about the handling of fuels, their flash points and their storage.

Working with Language
Q1. Find ten examples of verbs in the simple present tense in the text ‘Fire: Friend and Foe’ and write them down here. Do not include any passive verbs.
__________    __________   __________   _________   __________   __________  __________    __________   __________   _________
Ans. combines
comes
takes
bursts
heat
means
remove
absorbs
continue
flow
          
Q2. Fill in the blanks in the sentences below with words from the box. You may use a word more than once.

(i) Gandhiji’s life was devoted to the _________ of justice and fair play.
(ii) Have you insured your house against __________ ?
(iii) Diamond is nothing but __________ in its pure form.
(iv) If you put too much coal on the fire at once you will __________ it.  
(v) Smoking is said to be the main __________ of heart disease.
(vi) When asked by an ambitious writer whether he should put some ___________ into his stories, Somerset Maugham murmured, “No, the other way round”.
(vii) She is a __________ copy of her mother.
(viii) It is often difficult to _________ a yawn when you listen to a long speech on the value of time.
Ans. (i) Gandhiji’s life was devoted to the cause of justice and fair play.
(ii) Have you insured your house against fire ?
(iii) Diamond is nothing but carbon in its pure form.
(iv) If you put too much coal on the fire at once you will smother it.  
(v) Smoking is said to be the main cause of heart disease.
(vi) When asked by an ambitious writer whether he should put some fire into his stories, Somerset Maugham murmured, “No, the other way round”.
(vii) She is a carbon copy of her mother.
(viii) It is often difficult to smother a yawn when you listen to a long speech on the value of time.

Q3. One word is italicised in each sentence. Find its opposite in the box and fill in the blanks.

(i) You were required to keep all the doors open, not _________
(ii) PUPIL: What mark did I get in yesterday’s Maths test? TEACHER: You got what you get when you add five and five and _________ ten from the total.
(iii) Run four kilometres a day to preserve your health. Run a lot more to ________ it.
(iv) If a doctor advises a lean and lanky patient to reduce his weight further, be sure he is doing it to ________ his income.
(v) The world is too much with us; late and soon, Getting and __________ we lay waste our powers. – WORDSWORTH
Ans. (i) You were required to keep all the doors open, not shut.
(ii) PUPIL: What mark did I get in yesterday’s Maths test? TEACHER: You got what you get when you add five and five and subtract ten from the total.
(iii) Run four kilometres a day to preserve your health. Run a lot more to destroy it.
(iv) If a doctor advises a lean and lanky patient to reduce his weight further, be sure he is doing it to increase his income.
(v) The world is too much with us; late and soon, Getting and spending we lay waste our powers. – WORDSWORTH

Q4. Use the words given in the box to fill in the blanks in the sentences below.

(i) The cat chased the mouse __________ the lawn.
(ii) We were not allowed to cross the frontier. So we drove __________ it as far as we could and came back happy.
(iii) The horse went ___________ the winning post and had to be stopped with difficulty.
(iv) It is not difficult to see your plan. Anyone can see __________ your motive.
(v) Go _________ the yellow line, then turn left. You will reach the post office in five minutes.
Ans. (i) The cat chased the mouse across the lawn.
(ii) We were not allowed to cross the frontier. So we drove along it as far as we could and came back happy.
(iii) The horse went past the winning post and had to be stopped with difficulty.
(iv) It is not difficult to see your plan. Anyone can see through your motive.
(v) Go along the yellow line, then turn left. You will reach the post office in five minutes.