Comprehension check…
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
Ans: (c) fire
(ii) Fire
(a) fire is a
energy.
(b) fire is
heat and light.
(c) fire is the
result of a chemical reaction.
Ans: (c) fire is the result of a chemical
reaction.
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.
(iii) Oxygen
combines with carbon and hydrogen.
(i) (ii) (iii)
(iv)
(ii) (iii) (i)
(iv)
(iv) (iii) (ii)
(i)
(iv) (ii) (iii)
(i)
Ans: (iv) (ii) (iii) (i)
Working with
the text…
1. What do
you understand by the 'flash point' of a fuel?
Ans: The particular temperature at which
a fuel begins to burn is called its 'flash point'.
2. (i) What
are some common uses of fire?
Ans: The common uses of fire are - to
cook food, warm our houses in winter and to generate electricity.
(ii) In what
sense is fire a "bad master"?
Ans: If fire gets out of control, it
burns homes, shops and vast area of forests. It also kills or injures hundreds
of people. Then it is called a bad master.
3. Match
items in Column A with those in Column B.
A. B
(I) fuel -lighted match stick
(ii)
oxygen -air
(iii) heat -coal
-burning coal
-wood
- smouldering paper
-cooking gas
Ans: (i) fuel - coal, wood, cooking gas
(ii) Oxygen -
air
(iii) heat-
lighted match stick, burning coal, smouldering paper.
4. What are
the three main ways in which a fire can be controlled or put out?
Ans: The three ways are:-
(i) Take away the fuel.
(ii) Prevent
Oxygen from reaching it.
(iii) Remove
the heat.
5. Match the
items in box A with those in box B
|
A |
|
(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 |
|
B |
|
• 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. |
Ans:
|
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. |
6. Why does
a burning candle go out when you blow on it?
Ans: When we blow on a burning candle, we
remove the hot air around the flame. It brings down its temperature below the
flash point, and the candle goes out.
7. Spraying
water is not a good way of putting out an oil fire or an electric fire. Why not?
Ans: When we spray water onto an oil
fire, the oil will float on the surface of the water and continues to burn.
Water is a good conductor of electricity. So the person spraying water can get
electric shock and get killed.
8. What are
some of the things you should do to prevent fire at home and in the school?
Ans: (a) Keep the cylinder at a safe
distance.
(b) We should
put fire extinguisher at home and in the school.
c) We must
follow the norms for the construction of buildings.
Working with
Language…
1. Read the
sentences. To burn paper or a piece of 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 burns.
The verbs in
the italics are in the simple present tense. When we use it, we are not
thinking only about the present. We use it to say that something happens all
the time or repeatedly, or that something is true in general.
Find ten
examples of verbs in the simple present tense in the tense ‘Fire: Friend and Foe’ and write them down
here. Do not include any passive verbs.
Ans:
(i) comes (ii) blows
(iii)
bursts (iv) do not make
(v) heat (vi) catches
(vii)
combines (viii) begins
(ix) means (x) use
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.
Ans:
(i) cause (ii) fire
(iii) carbon (iv) smother
(v) cause (vi) fire
(vii) carbon (Viii) smother
3. One word
is italicized 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 marks 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
kilometers a day to preserve your health. Run a 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) shut (ii) subtract(iii) destroy
(iv) increase (v) spending.
4. 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 happily.
(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) across (ii) along (iii) past
(iv) through (v) along.