Page 1
CBSE VII | SCIENCE
Sample Paper – 2 Solution
CBSE Board
Class VII Science
Sample Paper – 2 Solution
Term II
SECTION A
1. (d)
Sphygmomanometer is used to measure the blood pressure.
2. (b)
Seed formation takes place during sexual reproduction in plants. Cutting, grafting and
tissue culture are methods of propagating plants asexually.
3. (b)
Deforestation is the process of cutting more and more tress from the forests to
accommodate growing population and to provide space for industries.
4. (a)
Oxygen is a renewable resource because it is continuously supplied by plants during
photosynthesis.
5. (b)
In the method of galvanization, surface of iron is coated with a layer of more active
metal like zinc.
Zinc metal prevents the surface of iron from coming in the contact with air and
moisture and thus, protects it from rusting.
6. (a)
In a chemical change, new products are formed. The new substances formed have
properties entirely different from the original substances.
Ca(OH) 2 + 2 HCl ? CaCl 2 + 2 H 2O
7. (a)
Burning of a magnesium ribbon is a chemical change. When magnesium ribbon is held
over the flame of a burner, it burns with a dazzling white light to give a new substance
called magnesium oxide.
2Mg + O 2 ? 2MgO
Magnesium Oxygen Magnesium oxide
Page 2
CBSE VII | SCIENCE
Sample Paper – 2 Solution
CBSE Board
Class VII Science
Sample Paper – 2 Solution
Term II
SECTION A
1. (d)
Sphygmomanometer is used to measure the blood pressure.
2. (b)
Seed formation takes place during sexual reproduction in plants. Cutting, grafting and
tissue culture are methods of propagating plants asexually.
3. (b)
Deforestation is the process of cutting more and more tress from the forests to
accommodate growing population and to provide space for industries.
4. (a)
Oxygen is a renewable resource because it is continuously supplied by plants during
photosynthesis.
5. (b)
In the method of galvanization, surface of iron is coated with a layer of more active
metal like zinc.
Zinc metal prevents the surface of iron from coming in the contact with air and
moisture and thus, protects it from rusting.
6. (a)
In a chemical change, new products are formed. The new substances formed have
properties entirely different from the original substances.
Ca(OH) 2 + 2 HCl ? CaCl 2 + 2 H 2O
7. (a)
Burning of a magnesium ribbon is a chemical change. When magnesium ribbon is held
over the flame of a burner, it burns with a dazzling white light to give a new substance
called magnesium oxide.
2Mg + O 2 ? 2MgO
Magnesium Oxygen Magnesium oxide
CBSE VII | SCIENCE
Sample Paper – 2 Solution
8. (d)
Boiling of water, melting of ice and lightning of bulb is a physical change. No chemical
reaction takes place and no new products are formed. However, rusting of iron is a
chemical change. Iron article chemically reacts with air and moisture to form a flaky
reddish brown layer of hydrated iron (III) oxide, known as rust.
9. (d)
Sodium hydroxide base is used in the soap and detergent industry.
10. (d)
The filament of an electric bulb is made of a thin wire of tungsten.
11. (d)
Compact fluorescent lamps (CFLs) reduce wastage of electricity and can be fixed in
ordinary bulb holders.
12. (d)
A current carrying coil of an insulated wire wrapped around a piece of iron is called an
electromagnet.
13. (b)
A non-luminous object does not produce its own light, but reflects light from other
sources.
14. (b)
An image formed by a plane mirror is erect and of the same size as the object.
15. (a)
Absorber of radiant energy
SECTION B
16. Septic tanks are low cost onsite sewage disposal systems suitable for places where
there is no sewerage system. It can be used for hospitals, isolated buildings or a cluster
of 4 to 5 houses.
17.
(a) Mango, apple and orange. (Any two)
(b) Castor and balsam
Page 3
CBSE VII | SCIENCE
Sample Paper – 2 Solution
CBSE Board
Class VII Science
Sample Paper – 2 Solution
Term II
SECTION A
1. (d)
Sphygmomanometer is used to measure the blood pressure.
2. (b)
Seed formation takes place during sexual reproduction in plants. Cutting, grafting and
tissue culture are methods of propagating plants asexually.
3. (b)
Deforestation is the process of cutting more and more tress from the forests to
accommodate growing population and to provide space for industries.
4. (a)
Oxygen is a renewable resource because it is continuously supplied by plants during
photosynthesis.
5. (b)
In the method of galvanization, surface of iron is coated with a layer of more active
metal like zinc.
Zinc metal prevents the surface of iron from coming in the contact with air and
moisture and thus, protects it from rusting.
6. (a)
In a chemical change, new products are formed. The new substances formed have
properties entirely different from the original substances.
Ca(OH) 2 + 2 HCl ? CaCl 2 + 2 H 2O
7. (a)
Burning of a magnesium ribbon is a chemical change. When magnesium ribbon is held
over the flame of a burner, it burns with a dazzling white light to give a new substance
called magnesium oxide.
2Mg + O 2 ? 2MgO
Magnesium Oxygen Magnesium oxide
CBSE VII | SCIENCE
Sample Paper – 2 Solution
8. (d)
Boiling of water, melting of ice and lightning of bulb is a physical change. No chemical
reaction takes place and no new products are formed. However, rusting of iron is a
chemical change. Iron article chemically reacts with air and moisture to form a flaky
reddish brown layer of hydrated iron (III) oxide, known as rust.
9. (d)
Sodium hydroxide base is used in the soap and detergent industry.
10. (d)
The filament of an electric bulb is made of a thin wire of tungsten.
11. (d)
Compact fluorescent lamps (CFLs) reduce wastage of electricity and can be fixed in
ordinary bulb holders.
12. (d)
A current carrying coil of an insulated wire wrapped around a piece of iron is called an
electromagnet.
13. (b)
A non-luminous object does not produce its own light, but reflects light from other
sources.
14. (b)
An image formed by a plane mirror is erect and of the same size as the object.
15. (a)
Absorber of radiant energy
SECTION B
16. Septic tanks are low cost onsite sewage disposal systems suitable for places where
there is no sewerage system. It can be used for hospitals, isolated buildings or a cluster
of 4 to 5 houses.
17.
(a) Mango, apple and orange. (Any two)
(b) Castor and balsam
CBSE VII | SCIENCE
Sample Paper – 2 Solution
18. Tooth decay can be prevented with the help of the following measures:
1. After every meal, one should rinse the mouth thoroughly with water.
2. One should brush the teeth twice a day.
3. Sugary food must be eaten in minimal quantities.
4. Dental floss must be used to keep the space between the teeth clean.
19.
i. Melting of ice: During this change, the water changes from its solid state to liquid
state and it can be solidified again. Hence, this is a reversible change.
ii. Lightening of an electric bulb: During this change, electricity is passed through the
filament which becomes white hot and glows, but when the switch is off, the
filament returns to its original shape and condition; hence, it is reversible.
20. Iron is coated with chromium to prevent rusting. It is called chrome-plating. Chromium
metal is resistant to the action of air and moisture. So, when a layer of chromium is
deposited on an iron object, the iron object is protected from rusting.
21. Light has a dual nature as it exhibits the properties of both, waves and particles
depending on the situation.
22. A spherical mirror is that mirror whose reflecting surface is a part of a hollow sphere of
glass. In a concave mirror, the reflecting surface is the bent-in surface.
SECTION C
23.
(a)
i. This is because the pulmonary artery carries blood away from the heart and not
towards it like a vein does.
ii. Since the blood flows through arteries rapidly at a high pressure, the arteries
have thick elastic walls.
iii. The red blood cells contain a red pigment called haemoglobin. The presence of
haemoglobin makes blood appear red.
(b) Platelets form a network of cells on the cut or wound and thus, form a blood clot.
24.
(a) The process of taking out silk fibres from the cocoon is called reeling. Cocoons are
collected first. These cocoons are then treated in hot water. Hot water makes the silk
fibres of the cocoons separate. The threads are then unwound to obtain the long silk
fibre.
Page 4
CBSE VII | SCIENCE
Sample Paper – 2 Solution
CBSE Board
Class VII Science
Sample Paper – 2 Solution
Term II
SECTION A
1. (d)
Sphygmomanometer is used to measure the blood pressure.
2. (b)
Seed formation takes place during sexual reproduction in plants. Cutting, grafting and
tissue culture are methods of propagating plants asexually.
3. (b)
Deforestation is the process of cutting more and more tress from the forests to
accommodate growing population and to provide space for industries.
4. (a)
Oxygen is a renewable resource because it is continuously supplied by plants during
photosynthesis.
5. (b)
In the method of galvanization, surface of iron is coated with a layer of more active
metal like zinc.
Zinc metal prevents the surface of iron from coming in the contact with air and
moisture and thus, protects it from rusting.
6. (a)
In a chemical change, new products are formed. The new substances formed have
properties entirely different from the original substances.
Ca(OH) 2 + 2 HCl ? CaCl 2 + 2 H 2O
7. (a)
Burning of a magnesium ribbon is a chemical change. When magnesium ribbon is held
over the flame of a burner, it burns with a dazzling white light to give a new substance
called magnesium oxide.
2Mg + O 2 ? 2MgO
Magnesium Oxygen Magnesium oxide
CBSE VII | SCIENCE
Sample Paper – 2 Solution
8. (d)
Boiling of water, melting of ice and lightning of bulb is a physical change. No chemical
reaction takes place and no new products are formed. However, rusting of iron is a
chemical change. Iron article chemically reacts with air and moisture to form a flaky
reddish brown layer of hydrated iron (III) oxide, known as rust.
9. (d)
Sodium hydroxide base is used in the soap and detergent industry.
10. (d)
The filament of an electric bulb is made of a thin wire of tungsten.
11. (d)
Compact fluorescent lamps (CFLs) reduce wastage of electricity and can be fixed in
ordinary bulb holders.
12. (d)
A current carrying coil of an insulated wire wrapped around a piece of iron is called an
electromagnet.
13. (b)
A non-luminous object does not produce its own light, but reflects light from other
sources.
14. (b)
An image formed by a plane mirror is erect and of the same size as the object.
15. (a)
Absorber of radiant energy
SECTION B
16. Septic tanks are low cost onsite sewage disposal systems suitable for places where
there is no sewerage system. It can be used for hospitals, isolated buildings or a cluster
of 4 to 5 houses.
17.
(a) Mango, apple and orange. (Any two)
(b) Castor and balsam
CBSE VII | SCIENCE
Sample Paper – 2 Solution
18. Tooth decay can be prevented with the help of the following measures:
1. After every meal, one should rinse the mouth thoroughly with water.
2. One should brush the teeth twice a day.
3. Sugary food must be eaten in minimal quantities.
4. Dental floss must be used to keep the space between the teeth clean.
19.
i. Melting of ice: During this change, the water changes from its solid state to liquid
state and it can be solidified again. Hence, this is a reversible change.
ii. Lightening of an electric bulb: During this change, electricity is passed through the
filament which becomes white hot and glows, but when the switch is off, the
filament returns to its original shape and condition; hence, it is reversible.
20. Iron is coated with chromium to prevent rusting. It is called chrome-plating. Chromium
metal is resistant to the action of air and moisture. So, when a layer of chromium is
deposited on an iron object, the iron object is protected from rusting.
21. Light has a dual nature as it exhibits the properties of both, waves and particles
depending on the situation.
22. A spherical mirror is that mirror whose reflecting surface is a part of a hollow sphere of
glass. In a concave mirror, the reflecting surface is the bent-in surface.
SECTION C
23.
(a)
i. This is because the pulmonary artery carries blood away from the heart and not
towards it like a vein does.
ii. Since the blood flows through arteries rapidly at a high pressure, the arteries
have thick elastic walls.
iii. The red blood cells contain a red pigment called haemoglobin. The presence of
haemoglobin makes blood appear red.
(b) Platelets form a network of cells on the cut or wound and thus, form a blood clot.
24.
(a) The process of taking out silk fibres from the cocoon is called reeling. Cocoons are
collected first. These cocoons are then treated in hot water. Hot water makes the silk
fibres of the cocoons separate. The threads are then unwound to obtain the long silk
fibre.
CBSE VII | SCIENCE
Sample Paper – 2 Solution
(b) The varieties of silk are tassar silk, mulberry silk, muga silk, kosa silk and eri silk.
Mulberry silk is most commonly used. Mulberry silk is soft, lustrous and elastic and
can be dyed with attractive colours.
25.
(Label any two parts)
26.
(a) An indicator is a dye that changes color when it is put into an acid or a base.
(b) Put one drop of each liquid on turmeric paper, turn by turn.
(i) The liquid which turns the yellow turmeric paper red will be sodium hydroxide
(base). The red turmeric paper formed here can now be used to test sulphuric
acid.
(ii) Put one drop each of the remaining two liquids on red turmeric paper. The liquid
which makes the red turmeric paper yellow again will be sulphuric acid (This is
because sulphuric acid cancels the effect of sodium hydroxide base on turmeric
paper).
(iii) The liquid which has no effect on the red turned turmeric paper will be salt
solution (because it is neutral).
Page 5
CBSE VII | SCIENCE
Sample Paper – 2 Solution
CBSE Board
Class VII Science
Sample Paper – 2 Solution
Term II
SECTION A
1. (d)
Sphygmomanometer is used to measure the blood pressure.
2. (b)
Seed formation takes place during sexual reproduction in plants. Cutting, grafting and
tissue culture are methods of propagating plants asexually.
3. (b)
Deforestation is the process of cutting more and more tress from the forests to
accommodate growing population and to provide space for industries.
4. (a)
Oxygen is a renewable resource because it is continuously supplied by plants during
photosynthesis.
5. (b)
In the method of galvanization, surface of iron is coated with a layer of more active
metal like zinc.
Zinc metal prevents the surface of iron from coming in the contact with air and
moisture and thus, protects it from rusting.
6. (a)
In a chemical change, new products are formed. The new substances formed have
properties entirely different from the original substances.
Ca(OH) 2 + 2 HCl ? CaCl 2 + 2 H 2O
7. (a)
Burning of a magnesium ribbon is a chemical change. When magnesium ribbon is held
over the flame of a burner, it burns with a dazzling white light to give a new substance
called magnesium oxide.
2Mg + O 2 ? 2MgO
Magnesium Oxygen Magnesium oxide
CBSE VII | SCIENCE
Sample Paper – 2 Solution
8. (d)
Boiling of water, melting of ice and lightning of bulb is a physical change. No chemical
reaction takes place and no new products are formed. However, rusting of iron is a
chemical change. Iron article chemically reacts with air and moisture to form a flaky
reddish brown layer of hydrated iron (III) oxide, known as rust.
9. (d)
Sodium hydroxide base is used in the soap and detergent industry.
10. (d)
The filament of an electric bulb is made of a thin wire of tungsten.
11. (d)
Compact fluorescent lamps (CFLs) reduce wastage of electricity and can be fixed in
ordinary bulb holders.
12. (d)
A current carrying coil of an insulated wire wrapped around a piece of iron is called an
electromagnet.
13. (b)
A non-luminous object does not produce its own light, but reflects light from other
sources.
14. (b)
An image formed by a plane mirror is erect and of the same size as the object.
15. (a)
Absorber of radiant energy
SECTION B
16. Septic tanks are low cost onsite sewage disposal systems suitable for places where
there is no sewerage system. It can be used for hospitals, isolated buildings or a cluster
of 4 to 5 houses.
17.
(a) Mango, apple and orange. (Any two)
(b) Castor and balsam
CBSE VII | SCIENCE
Sample Paper – 2 Solution
18. Tooth decay can be prevented with the help of the following measures:
1. After every meal, one should rinse the mouth thoroughly with water.
2. One should brush the teeth twice a day.
3. Sugary food must be eaten in minimal quantities.
4. Dental floss must be used to keep the space between the teeth clean.
19.
i. Melting of ice: During this change, the water changes from its solid state to liquid
state and it can be solidified again. Hence, this is a reversible change.
ii. Lightening of an electric bulb: During this change, electricity is passed through the
filament which becomes white hot and glows, but when the switch is off, the
filament returns to its original shape and condition; hence, it is reversible.
20. Iron is coated with chromium to prevent rusting. It is called chrome-plating. Chromium
metal is resistant to the action of air and moisture. So, when a layer of chromium is
deposited on an iron object, the iron object is protected from rusting.
21. Light has a dual nature as it exhibits the properties of both, waves and particles
depending on the situation.
22. A spherical mirror is that mirror whose reflecting surface is a part of a hollow sphere of
glass. In a concave mirror, the reflecting surface is the bent-in surface.
SECTION C
23.
(a)
i. This is because the pulmonary artery carries blood away from the heart and not
towards it like a vein does.
ii. Since the blood flows through arteries rapidly at a high pressure, the arteries
have thick elastic walls.
iii. The red blood cells contain a red pigment called haemoglobin. The presence of
haemoglobin makes blood appear red.
(b) Platelets form a network of cells on the cut or wound and thus, form a blood clot.
24.
(a) The process of taking out silk fibres from the cocoon is called reeling. Cocoons are
collected first. These cocoons are then treated in hot water. Hot water makes the silk
fibres of the cocoons separate. The threads are then unwound to obtain the long silk
fibre.
CBSE VII | SCIENCE
Sample Paper – 2 Solution
(b) The varieties of silk are tassar silk, mulberry silk, muga silk, kosa silk and eri silk.
Mulberry silk is most commonly used. Mulberry silk is soft, lustrous and elastic and
can be dyed with attractive colours.
25.
(Label any two parts)
26.
(a) An indicator is a dye that changes color when it is put into an acid or a base.
(b) Put one drop of each liquid on turmeric paper, turn by turn.
(i) The liquid which turns the yellow turmeric paper red will be sodium hydroxide
(base). The red turmeric paper formed here can now be used to test sulphuric
acid.
(ii) Put one drop each of the remaining two liquids on red turmeric paper. The liquid
which makes the red turmeric paper yellow again will be sulphuric acid (This is
because sulphuric acid cancels the effect of sodium hydroxide base on turmeric
paper).
(iii) The liquid which has no effect on the red turned turmeric paper will be salt
solution (because it is neutral).
CBSE VII | SCIENCE
Sample Paper – 2 Solution
27.
(a) When an iron object is exposed to air and moisture, a flaky reddish brown layer of
hydrated iron (III) oxide is formed on its surface. This substance is called as rust and
the process of its formation is called rusting.
This is the only change that effects iron articles and slowly destroys them. Since iron
is used in making bridges, ships, cars, truck and many other objects. Rusting
weakens the structures of iron objects and cuts short their life.
Following is the chemical equation to show the process of rusting of iron:
Fe + O 2 + H 2O ? Fe 2O 3
Iron Oxygen Water Rust
(From the Air) (Iron oxide)
(b) Rusting of iron is considered a chemical change because a new substance called iron
oxide is formed in this process.
28.
i. Lime water is calcium hydroxide solution.
ii. When the gas evolved is passed through lime water, it turns milky.
iii. The turning of lime water milky shows the presence of carbon dioxide because when
Carbon dioxide (CO 2) is passed through lime water, white solid substance called
calcium carbonate is formed which makes lime water milky.
iv.
CH 3COOH + NaHCO 3 ? CO 2 + CH 3COONa + H 2O
Acetic acid Sodium Carbon Sodium Water
hydrogen dioxide acetate
carbonate
(Vinegar) (Baking soda)
CO 2 + [Ca(OH) 2] ? CaCO 3 + H 2O
Carbon dioxide Lime water Calcium Carbonate Water
29. Cool air is denser so it moves down whereas warm air is lighter so rises up hence
convection currents are formed that helps in circulating the cold air and keeps the room
cool.
If the air cooler is not kept higher up, then the cool air will remain at the surface layer
and warm air will remain at the top, hence no circulation of air will take place and room
will remain warm.
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