Class 9 Science: Solutions of Sample Practice Question Paper- 1 PDF Download

 Page 1


  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
CBSE 
Class IX Science 
Sample Paper – 1 Solution  
                                                                                                                           
Section A 
1. The practice of growing two or more crops simultaneously in the same field in a definite 
row pattern is called intercropping. 
 
2. Movement of nutrient elements through the living and non-living components of the 
biosphere is called a biogeochemical cycle. 
 
Section B 
3. Human activities which could lead to an increase in carbon dioxide content of air: 
(a) Burning of fossil fuels such as coal and petroleum  
(b) Deforestation 
(c) Burning associated with agricultural practices 
OR 
Role of the Sun in the formation of soil: 
? The Sun plays an important role in weathering of rocks for soil formation.  
? It heats up the rocks during the day. Heating causes the rocks to expand.  
? During the night, the rocks cool down and contract. Different parts of a rock expand 
and contract at different rates resulting in its cracking and breaking up into smaller 
pieces or fragments.  
 
4. The electronic configuration of an atom plays an important role in determining the 
chemical behaviour of an element. 
? When the atom of an element has a completely filled outermost shell, the element 
will be chemically unreactive. 
? When the atom of an element has less than 8 electrons in its outermost shell, the 
element will be reactive. 
 
5. Newton’s first law of motion is the law of inertia which states that a body at rest will 
continue to stay at rest and a body in motion will continue to be in the state of motion 
until an external force is applied to it. 
Therefore, case (ii) indicates Newton’s first law.  
 
 
 
 
  
Page 2


  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
CBSE 
Class IX Science 
Sample Paper – 1 Solution  
                                                                                                                           
Section A 
1. The practice of growing two or more crops simultaneously in the same field in a definite 
row pattern is called intercropping. 
 
2. Movement of nutrient elements through the living and non-living components of the 
biosphere is called a biogeochemical cycle. 
 
Section B 
3. Human activities which could lead to an increase in carbon dioxide content of air: 
(a) Burning of fossil fuels such as coal and petroleum  
(b) Deforestation 
(c) Burning associated with agricultural practices 
OR 
Role of the Sun in the formation of soil: 
? The Sun plays an important role in weathering of rocks for soil formation.  
? It heats up the rocks during the day. Heating causes the rocks to expand.  
? During the night, the rocks cool down and contract. Different parts of a rock expand 
and contract at different rates resulting in its cracking and breaking up into smaller 
pieces or fragments.  
 
4. The electronic configuration of an atom plays an important role in determining the 
chemical behaviour of an element. 
? When the atom of an element has a completely filled outermost shell, the element 
will be chemically unreactive. 
? When the atom of an element has less than 8 electrons in its outermost shell, the 
element will be reactive. 
 
5. Newton’s first law of motion is the law of inertia which states that a body at rest will 
continue to stay at rest and a body in motion will continue to be in the state of motion 
until an external force is applied to it. 
Therefore, case (ii) indicates Newton’s first law.  
 
 
 
 
  
  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
Section C 
6.   
(a) Most rays passed through the thin gold foil undeviated.  
(b) Very few rays returned in the same path.  
(c) Some rays deflected through larger angles. 
 
7. Methods of weed control: 
(a) Mechanical method: It involves methods such as uprooting weeds manually, 
weeding with a trowel, hand hoeing, ploughing and burning. 
(b) Chemical method: It involves the use of chemical weed killers called herbicides or 
weedicides to kill or destroy weeds. 
(c) Biological method: It involves the deliberate use of insects or some other 
organisms which consume and specifically destroy weed plants. 
OR 
Green manuring is the practice of ploughing green plants into the soil for improving its 
fertility. Green manure provides organic matter and nutrients such as nitrogen and 
phosphorus to the soil.  
Commonly used green manure crops: Guar and Sunn hemp 
Macronutrients provided by green manure: Nitrogen and phosphorus 
 
8.   
(a) The force of attraction between particles of a gas is negligible or less. So, the 
particles freely move/flow in all possible directions, as a result the gas completely 
fills the vessel in which it is kept. 
(b) Freely moving particles of a gas hit the walls of its container continuously and 
randomly. Hence, such random and erratic motion of gas particles exerts pressure 
on the walls of the container. 
(c) Particles of a wooden table are rigid and have a fixed location. They also possess a 
definite shape and volume. Because of these properties, we should call a wooden 
table a solid substance. 
 
9. (i) Distance: It is the actual length covered by a body during the course of motion. 
As the distance only indicates the magnitude of the length covered without any 
element of the direction of the motion, it is a scalar quantity. The distance covered 
cannot be negative.  
 
(ii) Displacement: Displacement is the change in position made by the body during 
motion. Direction of the movement along with the magnitude of the change of 
position determines the value of displacement; therefore, it is a vector quantity.           
 
Page 3


  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
CBSE 
Class IX Science 
Sample Paper – 1 Solution  
                                                                                                                           
Section A 
1. The practice of growing two or more crops simultaneously in the same field in a definite 
row pattern is called intercropping. 
 
2. Movement of nutrient elements through the living and non-living components of the 
biosphere is called a biogeochemical cycle. 
 
Section B 
3. Human activities which could lead to an increase in carbon dioxide content of air: 
(a) Burning of fossil fuels such as coal and petroleum  
(b) Deforestation 
(c) Burning associated with agricultural practices 
OR 
Role of the Sun in the formation of soil: 
? The Sun plays an important role in weathering of rocks for soil formation.  
? It heats up the rocks during the day. Heating causes the rocks to expand.  
? During the night, the rocks cool down and contract. Different parts of a rock expand 
and contract at different rates resulting in its cracking and breaking up into smaller 
pieces or fragments.  
 
4. The electronic configuration of an atom plays an important role in determining the 
chemical behaviour of an element. 
? When the atom of an element has a completely filled outermost shell, the element 
will be chemically unreactive. 
? When the atom of an element has less than 8 electrons in its outermost shell, the 
element will be reactive. 
 
5. Newton’s first law of motion is the law of inertia which states that a body at rest will 
continue to stay at rest and a body in motion will continue to be in the state of motion 
until an external force is applied to it. 
Therefore, case (ii) indicates Newton’s first law.  
 
 
 
 
  
  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
Section C 
6.   
(a) Most rays passed through the thin gold foil undeviated.  
(b) Very few rays returned in the same path.  
(c) Some rays deflected through larger angles. 
 
7. Methods of weed control: 
(a) Mechanical method: It involves methods such as uprooting weeds manually, 
weeding with a trowel, hand hoeing, ploughing and burning. 
(b) Chemical method: It involves the use of chemical weed killers called herbicides or 
weedicides to kill or destroy weeds. 
(c) Biological method: It involves the deliberate use of insects or some other 
organisms which consume and specifically destroy weed plants. 
OR 
Green manuring is the practice of ploughing green plants into the soil for improving its 
fertility. Green manure provides organic matter and nutrients such as nitrogen and 
phosphorus to the soil.  
Commonly used green manure crops: Guar and Sunn hemp 
Macronutrients provided by green manure: Nitrogen and phosphorus 
 
8.   
(a) The force of attraction between particles of a gas is negligible or less. So, the 
particles freely move/flow in all possible directions, as a result the gas completely 
fills the vessel in which it is kept. 
(b) Freely moving particles of a gas hit the walls of its container continuously and 
randomly. Hence, such random and erratic motion of gas particles exerts pressure 
on the walls of the container. 
(c) Particles of a wooden table are rigid and have a fixed location. They also possess a 
definite shape and volume. Because of these properties, we should call a wooden 
table a solid substance. 
 
9. (i) Distance: It is the actual length covered by a body during the course of motion. 
As the distance only indicates the magnitude of the length covered without any 
element of the direction of the motion, it is a scalar quantity. The distance covered 
cannot be negative.  
 
(ii) Displacement: Displacement is the change in position made by the body during 
motion. Direction of the movement along with the magnitude of the change of 
position determines the value of displacement; therefore, it is a vector quantity.           
 
  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
10. Force (F) acting between the Earth (mass M) and the stone of mass (m) separated by 
the distance (r) by the universal law of gravitation is given by the equation      
?
2
M.m
F = G
r
. 
The mass of stone is negligible (too less) when compared to the mass of the Earth which 
is 6 ? 10
24
 kg. Thus, the stone falls on the Earth and the Earth does not rise towards the Sun.  
 
11.  The pressure is the ratio of force (F) exerted by a body to the area (A) upon which the 
body is exerting the force. Also, weight (W) is the force exerted by a body due to the 
Earth’s gravitational pull, i.e. F = W. 
 
?
?
? ? ? ?
2
W mg
Acceleration due to gravity (g) 10 m /s
W 8 10 80 N
?
?
? ? ? ?
? ? ?
22
2
Force (F)
Pressure (P) =
Area (A)
Area of the surface of the cuboid (A)= b
Assuming the surface of 50 20 cm to be in contact with the floor.
A 50 20 1000 cm 0.1 m
80
P 800 N/m
0.1
 
Pressure exerted by the block on the floor is 800 N/m
2
. 
OR 
 
?
?
?
?
??
11 2 2
24
2
Gravitation constant G  6.7 10 Nm / kg
Mass of the Earth  6
The 
10
force of gravitation is calculated b
 kg
Mass of ball = 2 kg
As the ball
y using the equation
M.m
F 
 is lying on the floor, 
= G
r
the 
? ?
?
??
??
?
??
24
11
2
distance between 
the ball and the Earth is equal to the radius of the Earth.
Substituting all the relevant values in the above equation
6 10 2
F = 6.7 10
6400
F 19.6 N
F 19.6 N
 
 
  
Page 4


  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
CBSE 
Class IX Science 
Sample Paper – 1 Solution  
                                                                                                                           
Section A 
1. The practice of growing two or more crops simultaneously in the same field in a definite 
row pattern is called intercropping. 
 
2. Movement of nutrient elements through the living and non-living components of the 
biosphere is called a biogeochemical cycle. 
 
Section B 
3. Human activities which could lead to an increase in carbon dioxide content of air: 
(a) Burning of fossil fuels such as coal and petroleum  
(b) Deforestation 
(c) Burning associated with agricultural practices 
OR 
Role of the Sun in the formation of soil: 
? The Sun plays an important role in weathering of rocks for soil formation.  
? It heats up the rocks during the day. Heating causes the rocks to expand.  
? During the night, the rocks cool down and contract. Different parts of a rock expand 
and contract at different rates resulting in its cracking and breaking up into smaller 
pieces or fragments.  
 
4. The electronic configuration of an atom plays an important role in determining the 
chemical behaviour of an element. 
? When the atom of an element has a completely filled outermost shell, the element 
will be chemically unreactive. 
? When the atom of an element has less than 8 electrons in its outermost shell, the 
element will be reactive. 
 
5. Newton’s first law of motion is the law of inertia which states that a body at rest will 
continue to stay at rest and a body in motion will continue to be in the state of motion 
until an external force is applied to it. 
Therefore, case (ii) indicates Newton’s first law.  
 
 
 
 
  
  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
Section C 
6.   
(a) Most rays passed through the thin gold foil undeviated.  
(b) Very few rays returned in the same path.  
(c) Some rays deflected through larger angles. 
 
7. Methods of weed control: 
(a) Mechanical method: It involves methods such as uprooting weeds manually, 
weeding with a trowel, hand hoeing, ploughing and burning. 
(b) Chemical method: It involves the use of chemical weed killers called herbicides or 
weedicides to kill or destroy weeds. 
(c) Biological method: It involves the deliberate use of insects or some other 
organisms which consume and specifically destroy weed plants. 
OR 
Green manuring is the practice of ploughing green plants into the soil for improving its 
fertility. Green manure provides organic matter and nutrients such as nitrogen and 
phosphorus to the soil.  
Commonly used green manure crops: Guar and Sunn hemp 
Macronutrients provided by green manure: Nitrogen and phosphorus 
 
8.   
(a) The force of attraction between particles of a gas is negligible or less. So, the 
particles freely move/flow in all possible directions, as a result the gas completely 
fills the vessel in which it is kept. 
(b) Freely moving particles of a gas hit the walls of its container continuously and 
randomly. Hence, such random and erratic motion of gas particles exerts pressure 
on the walls of the container. 
(c) Particles of a wooden table are rigid and have a fixed location. They also possess a 
definite shape and volume. Because of these properties, we should call a wooden 
table a solid substance. 
 
9. (i) Distance: It is the actual length covered by a body during the course of motion. 
As the distance only indicates the magnitude of the length covered without any 
element of the direction of the motion, it is a scalar quantity. The distance covered 
cannot be negative.  
 
(ii) Displacement: Displacement is the change in position made by the body during 
motion. Direction of the movement along with the magnitude of the change of 
position determines the value of displacement; therefore, it is a vector quantity.           
 
  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
10. Force (F) acting between the Earth (mass M) and the stone of mass (m) separated by 
the distance (r) by the universal law of gravitation is given by the equation      
?
2
M.m
F = G
r
. 
The mass of stone is negligible (too less) when compared to the mass of the Earth which 
is 6 ? 10
24
 kg. Thus, the stone falls on the Earth and the Earth does not rise towards the Sun.  
 
11.  The pressure is the ratio of force (F) exerted by a body to the area (A) upon which the 
body is exerting the force. Also, weight (W) is the force exerted by a body due to the 
Earth’s gravitational pull, i.e. F = W. 
 
?
?
? ? ? ?
2
W mg
Acceleration due to gravity (g) 10 m /s
W 8 10 80 N
?
?
? ? ? ?
? ? ?
22
2
Force (F)
Pressure (P) =
Area (A)
Area of the surface of the cuboid (A)= b
Assuming the surface of 50 20 cm to be in contact with the floor.
A 50 20 1000 cm 0.1 m
80
P 800 N/m
0.1
 
Pressure exerted by the block on the floor is 800 N/m
2
. 
OR 
 
?
?
?
?
??
11 2 2
24
2
Gravitation constant G  6.7 10 Nm / kg
Mass of the Earth  6
The 
10
force of gravitation is calculated b
 kg
Mass of ball = 2 kg
As the ball
y using the equation
M.m
F 
 is lying on the floor, 
= G
r
the 
? ?
?
??
??
?
??
24
11
2
distance between 
the ball and the Earth is equal to the radius of the Earth.
Substituting all the relevant values in the above equation
6 10 2
F = 6.7 10
6400
F 19.6 N
F 19.6 N
 
 
  
  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
12. Mass of silver in the ornament = m gram 
23
23
1
Massof goldin theornament m 0.01mgram
100
108gof Agcontains6.022 10 atoms
mgramof Agcontains(6.022 10 /108) m/100atoms
ratioof numberof atomsof goldandsilver Au:Ag
(6.022 1023/197) m/100:(6.022 1023 m)/108
1
? ? ?
?
??
?
? ? ? ? ?
? 08:19700
1:182.41 ?
   
OR 
 
(a)  
 
(b)  
 
 
(c)   
 
 
13.  
(a) AIDS (acquired immunodeficiency syndrome) 
(b) Retrovirus called HIV (human immunodeficiency virus) 
(c) Modes of transmission of the disease: 
(i) Unprotected sexual contact with an HIV-infected person 
(ii) Transfusion of blood contaminated with HIV 
 
Page 5


  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
CBSE 
Class IX Science 
Sample Paper – 1 Solution  
                                                                                                                           
Section A 
1. The practice of growing two or more crops simultaneously in the same field in a definite 
row pattern is called intercropping. 
 
2. Movement of nutrient elements through the living and non-living components of the 
biosphere is called a biogeochemical cycle. 
 
Section B 
3. Human activities which could lead to an increase in carbon dioxide content of air: 
(a) Burning of fossil fuels such as coal and petroleum  
(b) Deforestation 
(c) Burning associated with agricultural practices 
OR 
Role of the Sun in the formation of soil: 
? The Sun plays an important role in weathering of rocks for soil formation.  
? It heats up the rocks during the day. Heating causes the rocks to expand.  
? During the night, the rocks cool down and contract. Different parts of a rock expand 
and contract at different rates resulting in its cracking and breaking up into smaller 
pieces or fragments.  
 
4. The electronic configuration of an atom plays an important role in determining the 
chemical behaviour of an element. 
? When the atom of an element has a completely filled outermost shell, the element 
will be chemically unreactive. 
? When the atom of an element has less than 8 electrons in its outermost shell, the 
element will be reactive. 
 
5. Newton’s first law of motion is the law of inertia which states that a body at rest will 
continue to stay at rest and a body in motion will continue to be in the state of motion 
until an external force is applied to it. 
Therefore, case (ii) indicates Newton’s first law.  
 
 
 
 
  
  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
Section C 
6.   
(a) Most rays passed through the thin gold foil undeviated.  
(b) Very few rays returned in the same path.  
(c) Some rays deflected through larger angles. 
 
7. Methods of weed control: 
(a) Mechanical method: It involves methods such as uprooting weeds manually, 
weeding with a trowel, hand hoeing, ploughing and burning. 
(b) Chemical method: It involves the use of chemical weed killers called herbicides or 
weedicides to kill or destroy weeds. 
(c) Biological method: It involves the deliberate use of insects or some other 
organisms which consume and specifically destroy weed plants. 
OR 
Green manuring is the practice of ploughing green plants into the soil for improving its 
fertility. Green manure provides organic matter and nutrients such as nitrogen and 
phosphorus to the soil.  
Commonly used green manure crops: Guar and Sunn hemp 
Macronutrients provided by green manure: Nitrogen and phosphorus 
 
8.   
(a) The force of attraction between particles of a gas is negligible or less. So, the 
particles freely move/flow in all possible directions, as a result the gas completely 
fills the vessel in which it is kept. 
(b) Freely moving particles of a gas hit the walls of its container continuously and 
randomly. Hence, such random and erratic motion of gas particles exerts pressure 
on the walls of the container. 
(c) Particles of a wooden table are rigid and have a fixed location. They also possess a 
definite shape and volume. Because of these properties, we should call a wooden 
table a solid substance. 
 
9. (i) Distance: It is the actual length covered by a body during the course of motion. 
As the distance only indicates the magnitude of the length covered without any 
element of the direction of the motion, it is a scalar quantity. The distance covered 
cannot be negative.  
 
(ii) Displacement: Displacement is the change in position made by the body during 
motion. Direction of the movement along with the magnitude of the change of 
position determines the value of displacement; therefore, it is a vector quantity.           
 
  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
10. Force (F) acting between the Earth (mass M) and the stone of mass (m) separated by 
the distance (r) by the universal law of gravitation is given by the equation      
?
2
M.m
F = G
r
. 
The mass of stone is negligible (too less) when compared to the mass of the Earth which 
is 6 ? 10
24
 kg. Thus, the stone falls on the Earth and the Earth does not rise towards the Sun.  
 
11.  The pressure is the ratio of force (F) exerted by a body to the area (A) upon which the 
body is exerting the force. Also, weight (W) is the force exerted by a body due to the 
Earth’s gravitational pull, i.e. F = W. 
 
?
?
? ? ? ?
2
W mg
Acceleration due to gravity (g) 10 m /s
W 8 10 80 N
?
?
? ? ? ?
? ? ?
22
2
Force (F)
Pressure (P) =
Area (A)
Area of the surface of the cuboid (A)= b
Assuming the surface of 50 20 cm to be in contact with the floor.
A 50 20 1000 cm 0.1 m
80
P 800 N/m
0.1
 
Pressure exerted by the block on the floor is 800 N/m
2
. 
OR 
 
?
?
?
?
??
11 2 2
24
2
Gravitation constant G  6.7 10 Nm / kg
Mass of the Earth  6
The 
10
force of gravitation is calculated b
 kg
Mass of ball = 2 kg
As the ball
y using the equation
M.m
F 
 is lying on the floor, 
= G
r
the 
? ?
?
??
??
?
??
24
11
2
distance between 
the ball and the Earth is equal to the radius of the Earth.
Substituting all the relevant values in the above equation
6 10 2
F = 6.7 10
6400
F 19.6 N
F 19.6 N
 
 
  
  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
12. Mass of silver in the ornament = m gram 
23
23
1
Massof goldin theornament m 0.01mgram
100
108gof Agcontains6.022 10 atoms
mgramof Agcontains(6.022 10 /108) m/100atoms
ratioof numberof atomsof goldandsilver Au:Ag
(6.022 1023/197) m/100:(6.022 1023 m)/108
1
? ? ?
?
??
?
? ? ? ? ?
? 08:19700
1:182.41 ?
   
OR 
 
(a)  
 
(b)  
 
 
(c)   
 
 
13.  
(a) AIDS (acquired immunodeficiency syndrome) 
(b) Retrovirus called HIV (human immunodeficiency virus) 
(c) Modes of transmission of the disease: 
(i) Unprotected sexual contact with an HIV-infected person 
(ii) Transfusion of blood contaminated with HIV 
 
  
 
CBSE IX | SCIENCE 
 Sample Paper – 1 Solution 
 
     
14.  
(a) Clothes are washed with soap or detergent solution. This solution is hypertonic 
because it contains low water concentration as compared to the osmotic 
concentration of our skin cells. 
(b) Therefore, when skin cells come in contact with the detergent solution, they begin to 
lose more water by exosmosis after some time. 
(c) As a result, the skin over the fingers shrinks while washing clothes for a long time. 
 
15.  
(a) Carbon dioxide is required by plants to make food by photosynthesis. 
(b) It is also a greenhouse gas which traps the heat reflected by the Earth’s surface and 
keeps the atmosphere warm. 
(c) However, when the concentration of CO2 rises above normal levels, it traps more 
heat resulting in heating of the Earth’s atmosphere and an increase in the Earth’s 
temperature causing global warming. 
(d) Global warming is dangerous because it tends to melt polar ice and glaciers on 
mountains. This causes a rise in the water level of oceans and submerges several 
coastal areas and islands. 
(e) Therefore, although carbon dioxide is essential for plants, it can act as a pollutant in 
case of excess concentrations.  
 
Section D 
16. (a)  
(i) Bilateral symmetry: The type of body symmetry in which two sides of the body 
are mirror images of one another is called bilateral symmetry. 
Example: Earthworm 
(ii) Coelom: Body cavity lined with an epithelium derived from the mesoderm is 
called coelom.  
Example: Spider 
(iii) Diploblastic: Animals which have two germ layers—outer ectoderm and inner 
endoderm—in the embryo are said to be diploblastic.  
Example: Hydra 
(b) 
(i) Echinodermata 
(ii) Arachnida