Chapter 8: Fire Friend and Foe

English
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Chapter 8: Fire Friend and Foe

Class: VII

Exercise number-1

Question 1

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.

Answer 1

(i) Early man was frightened of fire.
(ii) Fire is the result of a chemical reaction.

 

Question 2

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.
– (i) (ii) (iii) (iv)
– (ii) (iii) (i) (iv)
– (iv) (iii) (ii) (i)
– (iv) (ii) (iii) (i)

Answer 2

(iv) (ii) (iii) (i)

 

 

Question 1

What do you understand by the ‘flash point’ of a fuel?

Answer 1

The temperature at which the fuel catches fire is known as its flash point.

 

Question 2

(i) What are some common uses of fire?
(ii) In what sense is it a "bad master"?

Answer 2

(i) To generate electricity, to cook food, to warm clothes in winter are some of the common uses of fire.
(ii)  It is a "bad master" because it can be very dangerous if it is not under control. Every year thousands of homes and shops are burnt because of fire. Fire destroys vast areas of forest and hundreds of people are killed or injured.

 

Question 3

Match items in Column A with those in Column B.

A		B
(i) (ii) (iii)	Fuel oxygen heat	– – – – – – –	lighted matchstick air coal burning coal wood smouldering paper cooking gas

 

Answer 3

A		B
(i) (ii) (iii)	Fuel oxygen heat	– – –	coal, wood, cooking gas air lighted matchstick, burning coal, smouldering paper

 

Question 4 

What are the three main ways in which a fire can be controlled or put out?

Answer 4

Fire can be controlled by taking away one of the three things required for burning.
The first way is to take the fuel away because if the fire has no fuel to feed on then no burning can take place.
The second way is to prevent oxygen from reaching it. If the fire is small then it can be put out with a sack or a damp blanket. These things keep the oxygen away from the burning material and sometimes carbon dioxide is used for extinguishing the fire.
The third way is to remove heat. The fuel can stop burning if the temperature can be brought below the flash point and to bring the temperature below the flash point, blowing on a burning matchstick or a candle should be done to remove the hot air around the flame. Sometimes water is sprayed on fire as it absorbs heat from burning fuel and lowers the temperature. It also does not allow oxygen to reach there and this way, fire is extinguished.

 

Question 5

Match the items in Box A with those in Box B

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

 

Answer 5

A	B
(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.

 

Question 6

Spraying water is not a good way of putting out an oil fire or an electrical fire. Why not?

Answer 6

If water is sprayed on an oil fire then the oil will float on top of the water and will continue to burn. This is very dangerous because water carrying burning oil can flow quickly and this can spread the fire. In case of an electrical fire, the person who is spraying water might receive an electric shock and be killed. Therefore, in an oil fire or an electrical fire, spraying water is not a good way.

 

Question 7

What are some of the things you should do to prevent a fire at home and in the school?

Answer 7
No solution available.

 

 

Question 1

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.
_______ _______
________– –

Answer 1
Combines Call Comes
Blow Bursts Gets
Means Stops Absorbs
Lowers – –

 

Question 2

Fill in the blanks in the sentences below with words from the box. You may use a word more than once.

carbon

cause

fire

smother

(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.

Answer 2

(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.

 

Question 3

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

spending

shut

destroy

subtract

increase

(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 addfive and five and ___________ ten from the total.
(iii) Run four kilometres a day to preserveyour health. Run a lot more to __________ it.
(iv) If a doctor advises a lean and lanky patient to reducehis weight further, be sure he is doing it to _____________ his income.
(v) The world is too much with us; late and soon, Gettingand ___________ we lay waste our powers.

Answer 3

(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 kilometers 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.

 

Question 4

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

across

along

past

through

(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.

Answer 4

(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 through your plan. Anyone can see your motive.
(v) Go along the yellow line, then turn left. You will reach the post office in five minutes.