Page 1
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
CBSE
Class VIII Science
Term 1
Sample Paper – 2 Solution
Time: 2 ½ hrs Total Marks: 80
SECTION A
1. Ans. Correct Option: [C]
Solution: The nitrogen-fixing bacteria present in leguminous plants add nitrogen to
the soil and thereby increase soil fertility.
2. Ans. Correct Option: [B]
Solution: The drip irrigation system provides water to the plants drop by drop. So,
water does not get wasted at all. In this way, it conserves maximum amount of
water.
3. Ans. Correct Option: [A]
Solution: Several communicable diseases such as cholera, tuberculosis, smallpox
and hepatitis can be prevented by vaccination. Diabetes, goitre and scurvy are
metabolic diseases and can be prevented by consuming or limiting the intake of
specific nutrients.
4. Ans. Correct Option: [B]
Solution: Children are protected against polio under the Pulse Polio Programme.
Polio disease is prevented by giving children the oral polio vaccine (OPV).
5. Ans. Correct Option: [C]
Solution: Teflon is used in cookware coating as it is non-sticky.
6. Ans. Correct Option: [C]
Solution: When sulphur is heated, it reacts with the atmospheric oxygen to form
sulphur dioxide gas. This gas when dissolved in water forms sulphurous acid
(H 2 sO 3).
S + O 2 ? SO 2
SO 2 + H 2 o ? H 2 sO 3
7. Ans. Correct Option: [C]
Solution: Copper is less reactive than zinc, so it cannot displace zinc from its
solution. Therefore, this reaction will not occur.
Page 2
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
CBSE
Class VIII Science
Term 1
Sample Paper – 2 Solution
Time: 2 ½ hrs Total Marks: 80
SECTION A
1. Ans. Correct Option: [C]
Solution: The nitrogen-fixing bacteria present in leguminous plants add nitrogen to
the soil and thereby increase soil fertility.
2. Ans. Correct Option: [B]
Solution: The drip irrigation system provides water to the plants drop by drop. So,
water does not get wasted at all. In this way, it conserves maximum amount of
water.
3. Ans. Correct Option: [A]
Solution: Several communicable diseases such as cholera, tuberculosis, smallpox
and hepatitis can be prevented by vaccination. Diabetes, goitre and scurvy are
metabolic diseases and can be prevented by consuming or limiting the intake of
specific nutrients.
4. Ans. Correct Option: [B]
Solution: Children are protected against polio under the Pulse Polio Programme.
Polio disease is prevented by giving children the oral polio vaccine (OPV).
5. Ans. Correct Option: [C]
Solution: Teflon is used in cookware coating as it is non-sticky.
6. Ans. Correct Option: [C]
Solution: When sulphur is heated, it reacts with the atmospheric oxygen to form
sulphur dioxide gas. This gas when dissolved in water forms sulphurous acid
(H 2 sO 3).
S + O 2 ? SO 2
SO 2 + H 2 o ? H 2 sO 3
7. Ans. Correct Option: [C]
Solution: Copper is less reactive than zinc, so it cannot displace zinc from its
solution. Therefore, this reaction will not occur.
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
8. Ans. Correct Option: [A]
Solution: Sodium metal produces lots of bubbles rapidly when it is added to cold
water.
9. Ans. Correct Option: [B]
Solution: Diesel acts as a fuel for heavy motor vehicles.
10. Ans. Correct Option: [B]
Solution: Perfumes are obtained from coal tar.
11. Ans. Correct Option: [A]
Solution: Bursting of an inflated balloon shows that gas exerts pressure on the
walls of its container.
12. Ans. Correct Option: [B]
Solution: The magnitude of non-contact forces decreases with the increase in
separation.
13. Ans. Correct Option: [D]
Solution: To minimise friction due to water (or any other liquid) and air (or any
other gas), the moving body should have a streamlined shape. Such a shape offers
minimum resistance due to friction.
14. Ans. Correct Option: [C]
Solution: Flapping of wings by bees and mosquitoes produces a high frequency
vibration in the air which is heard as buzzing.
15. Ans. Correct Option: [B]
Solution: Water is a denser medium, and hence, sound travels faster in it. Hence,
beating drums near the water body ensured that the sound travelled faster and
farther to be heard at far off places.
Page 3
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
CBSE
Class VIII Science
Term 1
Sample Paper – 2 Solution
Time: 2 ½ hrs Total Marks: 80
SECTION A
1. Ans. Correct Option: [C]
Solution: The nitrogen-fixing bacteria present in leguminous plants add nitrogen to
the soil and thereby increase soil fertility.
2. Ans. Correct Option: [B]
Solution: The drip irrigation system provides water to the plants drop by drop. So,
water does not get wasted at all. In this way, it conserves maximum amount of
water.
3. Ans. Correct Option: [A]
Solution: Several communicable diseases such as cholera, tuberculosis, smallpox
and hepatitis can be prevented by vaccination. Diabetes, goitre and scurvy are
metabolic diseases and can be prevented by consuming or limiting the intake of
specific nutrients.
4. Ans. Correct Option: [B]
Solution: Children are protected against polio under the Pulse Polio Programme.
Polio disease is prevented by giving children the oral polio vaccine (OPV).
5. Ans. Correct Option: [C]
Solution: Teflon is used in cookware coating as it is non-sticky.
6. Ans. Correct Option: [C]
Solution: When sulphur is heated, it reacts with the atmospheric oxygen to form
sulphur dioxide gas. This gas when dissolved in water forms sulphurous acid
(H 2 sO 3).
S + O 2 ? SO 2
SO 2 + H 2 o ? H 2 sO 3
7. Ans. Correct Option: [C]
Solution: Copper is less reactive than zinc, so it cannot displace zinc from its
solution. Therefore, this reaction will not occur.
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
8. Ans. Correct Option: [A]
Solution: Sodium metal produces lots of bubbles rapidly when it is added to cold
water.
9. Ans. Correct Option: [B]
Solution: Diesel acts as a fuel for heavy motor vehicles.
10. Ans. Correct Option: [B]
Solution: Perfumes are obtained from coal tar.
11. Ans. Correct Option: [A]
Solution: Bursting of an inflated balloon shows that gas exerts pressure on the
walls of its container.
12. Ans. Correct Option: [B]
Solution: The magnitude of non-contact forces decreases with the increase in
separation.
13. Ans. Correct Option: [D]
Solution: To minimise friction due to water (or any other liquid) and air (or any
other gas), the moving body should have a streamlined shape. Such a shape offers
minimum resistance due to friction.
14. Ans. Correct Option: [C]
Solution: Flapping of wings by bees and mosquitoes produces a high frequency
vibration in the air which is heard as buzzing.
15. Ans. Correct Option: [B]
Solution: Water is a denser medium, and hence, sound travels faster in it. Hence,
beating drums near the water body ensured that the sound travelled faster and
farther to be heard at far off places.
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
SECTION B
16. Ans. Due to the loss of forest cover, the percolation of rain water into the soil is
reduced. There is a decrease in the water-holding capacity of the soil. The
movement of water from the soil surface into the ground, i.e. the infiltration rate is
reduced. The rain water from deforested soil rushes into the rivers quickly,
eventually causing floods.
17. Ans. Loosening the soil allows the roots of plants to penetrate freely and deeper into
the soil and allows the roots to breathe easily. The loose soil helps in the growth of
worms and microbes present in the soil. These worms and microbes add humus to
the soil and enrich it. Loosening brings nutrient-rich soil to the top for the intake of
plants.
18. Ans. Leguminous plants have nitrogen-fixing bacteria in their root nodules, which
can fix atmospheric nitrogen and make it available to the plants and soil. These
bacteria enrich the soil with nitrogen and thereby increase soil fertility.
19. Ans. The polyester shirt will dry faster.
Cotton readily absorbs water, whereas polyester is not a good absorbent of water.
Therefore, polyester clothes dry faster.
20. Ans.
(i) Nitrogen is used for preserving food materials because of its inert behaviour.
(ii) Nitrogen is used up in the manufacture of fertilisers, ammonia etc.
21. Ans. This happens because the Earth pulls all objects towards itself due to the
attractive force called the force of gravity.
22. Ans. A violinist puts rosin on his bow to increase friction between the bow and the
violin strings, thereby producing sound.
Page 4
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
CBSE
Class VIII Science
Term 1
Sample Paper – 2 Solution
Time: 2 ½ hrs Total Marks: 80
SECTION A
1. Ans. Correct Option: [C]
Solution: The nitrogen-fixing bacteria present in leguminous plants add nitrogen to
the soil and thereby increase soil fertility.
2. Ans. Correct Option: [B]
Solution: The drip irrigation system provides water to the plants drop by drop. So,
water does not get wasted at all. In this way, it conserves maximum amount of
water.
3. Ans. Correct Option: [A]
Solution: Several communicable diseases such as cholera, tuberculosis, smallpox
and hepatitis can be prevented by vaccination. Diabetes, goitre and scurvy are
metabolic diseases and can be prevented by consuming or limiting the intake of
specific nutrients.
4. Ans. Correct Option: [B]
Solution: Children are protected against polio under the Pulse Polio Programme.
Polio disease is prevented by giving children the oral polio vaccine (OPV).
5. Ans. Correct Option: [C]
Solution: Teflon is used in cookware coating as it is non-sticky.
6. Ans. Correct Option: [C]
Solution: When sulphur is heated, it reacts with the atmospheric oxygen to form
sulphur dioxide gas. This gas when dissolved in water forms sulphurous acid
(H 2 sO 3).
S + O 2 ? SO 2
SO 2 + H 2 o ? H 2 sO 3
7. Ans. Correct Option: [C]
Solution: Copper is less reactive than zinc, so it cannot displace zinc from its
solution. Therefore, this reaction will not occur.
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
8. Ans. Correct Option: [A]
Solution: Sodium metal produces lots of bubbles rapidly when it is added to cold
water.
9. Ans. Correct Option: [B]
Solution: Diesel acts as a fuel for heavy motor vehicles.
10. Ans. Correct Option: [B]
Solution: Perfumes are obtained from coal tar.
11. Ans. Correct Option: [A]
Solution: Bursting of an inflated balloon shows that gas exerts pressure on the
walls of its container.
12. Ans. Correct Option: [B]
Solution: The magnitude of non-contact forces decreases with the increase in
separation.
13. Ans. Correct Option: [D]
Solution: To minimise friction due to water (or any other liquid) and air (or any
other gas), the moving body should have a streamlined shape. Such a shape offers
minimum resistance due to friction.
14. Ans. Correct Option: [C]
Solution: Flapping of wings by bees and mosquitoes produces a high frequency
vibration in the air which is heard as buzzing.
15. Ans. Correct Option: [B]
Solution: Water is a denser medium, and hence, sound travels faster in it. Hence,
beating drums near the water body ensured that the sound travelled faster and
farther to be heard at far off places.
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
SECTION B
16. Ans. Due to the loss of forest cover, the percolation of rain water into the soil is
reduced. There is a decrease in the water-holding capacity of the soil. The
movement of water from the soil surface into the ground, i.e. the infiltration rate is
reduced. The rain water from deforested soil rushes into the rivers quickly,
eventually causing floods.
17. Ans. Loosening the soil allows the roots of plants to penetrate freely and deeper into
the soil and allows the roots to breathe easily. The loose soil helps in the growth of
worms and microbes present in the soil. These worms and microbes add humus to
the soil and enrich it. Loosening brings nutrient-rich soil to the top for the intake of
plants.
18. Ans. Leguminous plants have nitrogen-fixing bacteria in their root nodules, which
can fix atmospheric nitrogen and make it available to the plants and soil. These
bacteria enrich the soil with nitrogen and thereby increase soil fertility.
19. Ans. The polyester shirt will dry faster.
Cotton readily absorbs water, whereas polyester is not a good absorbent of water.
Therefore, polyester clothes dry faster.
20. Ans.
(i) Nitrogen is used for preserving food materials because of its inert behaviour.
(ii) Nitrogen is used up in the manufacture of fertilisers, ammonia etc.
21. Ans. This happens because the Earth pulls all objects towards itself due to the
attractive force called the force of gravity.
22. Ans. A violinist puts rosin on his bow to increase friction between the bow and the
violin strings, thereby producing sound.
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
SECTION C
23. Ans.
(i) The negative effects of deforestation are
a. It causes an increase in the temperature of the Earth’s atmosphere leading to
global warming.
b. It leads to a shortage of wood and other forest products.
c. It causes soil erosion, makes the soil infertile and leads to desertification.
d. It causes frequent flooding of rivers, leading to loss of life and property.
e. It affects the water cycle, leading to a decrease in rainfall. This lowers the
groundwater level and causes droughts.
f. It leads to extinction of many wild animals and plants.
(ii) Increase in soil fertility cannot be caused by deforestation. Deforestation results
in extensive soil erosion due to which the lower, hard and rocky layers get
exposed. The fertile soil gets washed away during soil erosion. Hence, soil
fertility gets reduced and is not increased during deforestation.
24. Ans.
(i) Differences between manures and fertilisers:
Manures Fertilisers
1. Natural substances obtained by the
decomposition of plant and animal
remains by bacteria
1. Inorganic substances or compounds
2. Provides humus to the soil 2. Does not provide humus to the soil
3. Less rich in plant nutrients 3. Rich in plant nutrients such as
nitrogen, phosphorus and potassium
4. Can be prepared in fields 4. Prepared in factories
5. Inconvenient to store and transport 5. Easy to store and transport
6. Absorbed slowly by plants 6. Absorbed readily by plants
(ii) A cultivator is a tractor-driven agricultural implement used for ploughing. It has
many ploughshares which can dig into a considerable area of soil at the same
time, loosening and turning it. Because Mahesh uses a cultivator for ploughing,
he is able to save both labour and time as compared to Satish.
Page 5
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
CBSE
Class VIII Science
Term 1
Sample Paper – 2 Solution
Time: 2 ½ hrs Total Marks: 80
SECTION A
1. Ans. Correct Option: [C]
Solution: The nitrogen-fixing bacteria present in leguminous plants add nitrogen to
the soil and thereby increase soil fertility.
2. Ans. Correct Option: [B]
Solution: The drip irrigation system provides water to the plants drop by drop. So,
water does not get wasted at all. In this way, it conserves maximum amount of
water.
3. Ans. Correct Option: [A]
Solution: Several communicable diseases such as cholera, tuberculosis, smallpox
and hepatitis can be prevented by vaccination. Diabetes, goitre and scurvy are
metabolic diseases and can be prevented by consuming or limiting the intake of
specific nutrients.
4. Ans. Correct Option: [B]
Solution: Children are protected against polio under the Pulse Polio Programme.
Polio disease is prevented by giving children the oral polio vaccine (OPV).
5. Ans. Correct Option: [C]
Solution: Teflon is used in cookware coating as it is non-sticky.
6. Ans. Correct Option: [C]
Solution: When sulphur is heated, it reacts with the atmospheric oxygen to form
sulphur dioxide gas. This gas when dissolved in water forms sulphurous acid
(H 2 sO 3).
S + O 2 ? SO 2
SO 2 + H 2 o ? H 2 sO 3
7. Ans. Correct Option: [C]
Solution: Copper is less reactive than zinc, so it cannot displace zinc from its
solution. Therefore, this reaction will not occur.
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
8. Ans. Correct Option: [A]
Solution: Sodium metal produces lots of bubbles rapidly when it is added to cold
water.
9. Ans. Correct Option: [B]
Solution: Diesel acts as a fuel for heavy motor vehicles.
10. Ans. Correct Option: [B]
Solution: Perfumes are obtained from coal tar.
11. Ans. Correct Option: [A]
Solution: Bursting of an inflated balloon shows that gas exerts pressure on the
walls of its container.
12. Ans. Correct Option: [B]
Solution: The magnitude of non-contact forces decreases with the increase in
separation.
13. Ans. Correct Option: [D]
Solution: To minimise friction due to water (or any other liquid) and air (or any
other gas), the moving body should have a streamlined shape. Such a shape offers
minimum resistance due to friction.
14. Ans. Correct Option: [C]
Solution: Flapping of wings by bees and mosquitoes produces a high frequency
vibration in the air which is heard as buzzing.
15. Ans. Correct Option: [B]
Solution: Water is a denser medium, and hence, sound travels faster in it. Hence,
beating drums near the water body ensured that the sound travelled faster and
farther to be heard at far off places.
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
SECTION B
16. Ans. Due to the loss of forest cover, the percolation of rain water into the soil is
reduced. There is a decrease in the water-holding capacity of the soil. The
movement of water from the soil surface into the ground, i.e. the infiltration rate is
reduced. The rain water from deforested soil rushes into the rivers quickly,
eventually causing floods.
17. Ans. Loosening the soil allows the roots of plants to penetrate freely and deeper into
the soil and allows the roots to breathe easily. The loose soil helps in the growth of
worms and microbes present in the soil. These worms and microbes add humus to
the soil and enrich it. Loosening brings nutrient-rich soil to the top for the intake of
plants.
18. Ans. Leguminous plants have nitrogen-fixing bacteria in their root nodules, which
can fix atmospheric nitrogen and make it available to the plants and soil. These
bacteria enrich the soil with nitrogen and thereby increase soil fertility.
19. Ans. The polyester shirt will dry faster.
Cotton readily absorbs water, whereas polyester is not a good absorbent of water.
Therefore, polyester clothes dry faster.
20. Ans.
(i) Nitrogen is used for preserving food materials because of its inert behaviour.
(ii) Nitrogen is used up in the manufacture of fertilisers, ammonia etc.
21. Ans. This happens because the Earth pulls all objects towards itself due to the
attractive force called the force of gravity.
22. Ans. A violinist puts rosin on his bow to increase friction between the bow and the
violin strings, thereby producing sound.
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
SECTION C
23. Ans.
(i) The negative effects of deforestation are
a. It causes an increase in the temperature of the Earth’s atmosphere leading to
global warming.
b. It leads to a shortage of wood and other forest products.
c. It causes soil erosion, makes the soil infertile and leads to desertification.
d. It causes frequent flooding of rivers, leading to loss of life and property.
e. It affects the water cycle, leading to a decrease in rainfall. This lowers the
groundwater level and causes droughts.
f. It leads to extinction of many wild animals and plants.
(ii) Increase in soil fertility cannot be caused by deforestation. Deforestation results
in extensive soil erosion due to which the lower, hard and rocky layers get
exposed. The fertile soil gets washed away during soil erosion. Hence, soil
fertility gets reduced and is not increased during deforestation.
24. Ans.
(i) Differences between manures and fertilisers:
Manures Fertilisers
1. Natural substances obtained by the
decomposition of plant and animal
remains by bacteria
1. Inorganic substances or compounds
2. Provides humus to the soil 2. Does not provide humus to the soil
3. Less rich in plant nutrients 3. Rich in plant nutrients such as
nitrogen, phosphorus and potassium
4. Can be prepared in fields 4. Prepared in factories
5. Inconvenient to store and transport 5. Easy to store and transport
6. Absorbed slowly by plants 6. Absorbed readily by plants
(ii) A cultivator is a tractor-driven agricultural implement used for ploughing. It has
many ploughshares which can dig into a considerable area of soil at the same
time, loosening and turning it. Because Mahesh uses a cultivator for ploughing,
he is able to save both labour and time as compared to Satish.
CBSE VIII | SCIENCE
Sample Paper – 2 Solution
25. Ans.
(i) Dry fruits are sold in sealed and airtight packets to prevent them from the attack
of microbes and to preserve them for a longer time.
(ii) If we do not preserve food properly, then the food may get spoilt by the action of
microorganisms. Microorganisms which grow on food sometimes produce toxic
substances that make the food poisonous, causing serious illness and may even
result in death. Hence, it is important to preserve food properly to prevent it
from getting spoilt.
26. Ans.
(a) Terylene; PET
(b) Nylon
(c) Acrylic
(d) PET
27. Ans. Differences in physical properties of metals and non-metals:
Metals Non-metals
1. Metals are malleable and ductile. 1. Non-metals are neither malleable nor
ductile. They are brittle.
2. Metals are good conductors of heat and
electricity.
2. Non-metals are poor conductors of
heat and electricity (Except graphite
which is a good conductor of
electricity).
3. Metals are lustrous. 3. Non-metals are not lustrous. They
are dull.
4. Metals are strong. They have high
tensile strength (Except sodium and
potassium which are not strong and have
low tensile strength).
4. Non-metals are not strong. They have
a low tensile strength.
28. Ans. LPG stands for liquefied petroleum gas. LPG is a good fuel because of its
following advantages:
(i) LPG burns easily.
(ii) LPG has a high calorific value. Due to this, a given amount of LPG produces a lot
of heat.
(iii) LPG burns with a smokeless flame and hence does not cause air pollution.
(iv) LPG does not produce any poisonous gases on burning.
(v) LPG does not leave behind any solid residue on burning.
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