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``` Page 1

CBSE IX | SCIENCE
Sample Paper – 5 Solution

CBSE
Class IX Science
Sample Paper – 5 Solution

Section A
1. Rhizobium leguminosarum

2. Crop rotation

Section B
3. i) When an object exerts a force on another object, the second object exerts an equal
and opposite force on the first object.
ii) The third law of motion also holds true for the force of gravitation, i.e. when the
Earth exerts a force of attraction on an object, the object exerts the same force on the
Earth in the opposite direction.
OR

(i) Force constant
(ii) Gravitational

4. Particles which constitute the nucleus are called nucleons.
Protons and neutrons are the nucleons.
Atomic number of sodium is 11.
Atomic mass of sodium is 23.
No. of neutrons = 23 - 11 = 12
No. of nucleons = 23

5.
? In animals, subcutaneous fat functions as an insulating layer which prevents heat
loss from the body in the cold environment.
? So, animals in colder regions possess a thicker layer of adipose tissue to insulate
their body against the extreme cold.
? Fat also acts as a source of reserve food during periods of food scarcity.

Page 2

CBSE IX | SCIENCE
Sample Paper – 5 Solution

CBSE
Class IX Science
Sample Paper – 5 Solution

Section A
1. Rhizobium leguminosarum

2. Crop rotation

Section B
3. i) When an object exerts a force on another object, the second object exerts an equal
and opposite force on the first object.
ii) The third law of motion also holds true for the force of gravitation, i.e. when the
Earth exerts a force of attraction on an object, the object exerts the same force on the
Earth in the opposite direction.
OR

(i) Force constant
(ii) Gravitational

4. Particles which constitute the nucleus are called nucleons.
Protons and neutrons are the nucleons.
Atomic number of sodium is 11.
Atomic mass of sodium is 23.
No. of neutrons = 23 - 11 = 12
No. of nucleons = 23

5.
? In animals, subcutaneous fat functions as an insulating layer which prevents heat
loss from the body in the cold environment.
? So, animals in colder regions possess a thicker layer of adipose tissue to insulate
their body against the extreme cold.
? Fat also acts as a source of reserve food during periods of food scarcity.

CBSE IX | SCIENCE
Sample Paper – 5 Solution

Section C
6.
(a) Vacuole
(b) Golgi apparatus/Golgi body
(c) Mitochondria
7.
(a) Jointed appendages: Phylum Arthropoda
(b) Locomotion by setae: Phylum Annelida
(c) Body perforated with numerous pores: Phylum Porifera

OR
Differences between bony fish and cartilaginous fish:

Bony fish Cartilaginous fish
1. Bony endoskeleton 1. Cartilaginous endoskeleton
2. Contain four pairs of gill slits 2. Contain five–seven pairs of gill
slits
3. Mouth is terminal 3. Mouth is ventral
4. Caudal fin is homocercal 4. Caudal fin is heterocercal
6. Examples: Sea horse, carp 6. Examples: Electric ray, sting ray

8.
(i) To make the net force a balanced force, 10 N must be added to F1.
20 N + 10 N = 30 N
(ii) To move the object along the direction of F1, it has to be exceeded by 20 N so that it
becomes greater than F2.  So, now F1 becomes 40 N.
(iii) After carrying out the condition given in question (ii),
F = 40 N
So, net force = F = F1 - F2 = 40 N - 30 N = 10 N.
Acceleration F = ma
?
??
??
2
F 10 N
10
a 1 ms
10

9. The bouncing back of sound when it strikes a hard surface is called reflection of sound.
Laws of reflection:
i) The incident wave, reflected wave and normal all lie in the same plane.
ii) The angle of incidence is always equal to the angle of reflection.

OR
Page 3

CBSE IX | SCIENCE
Sample Paper – 5 Solution

CBSE
Class IX Science
Sample Paper – 5 Solution

Section A
1. Rhizobium leguminosarum

2. Crop rotation

Section B
3. i) When an object exerts a force on another object, the second object exerts an equal
and opposite force on the first object.
ii) The third law of motion also holds true for the force of gravitation, i.e. when the
Earth exerts a force of attraction on an object, the object exerts the same force on the
Earth in the opposite direction.
OR

(i) Force constant
(ii) Gravitational

4. Particles which constitute the nucleus are called nucleons.
Protons and neutrons are the nucleons.
Atomic number of sodium is 11.
Atomic mass of sodium is 23.
No. of neutrons = 23 - 11 = 12
No. of nucleons = 23

5.
? In animals, subcutaneous fat functions as an insulating layer which prevents heat
loss from the body in the cold environment.
? So, animals in colder regions possess a thicker layer of adipose tissue to insulate
their body against the extreme cold.
? Fat also acts as a source of reserve food during periods of food scarcity.

CBSE IX | SCIENCE
Sample Paper – 5 Solution

Section C
6.
(a) Vacuole
(b) Golgi apparatus/Golgi body
(c) Mitochondria
7.
(a) Jointed appendages: Phylum Arthropoda
(b) Locomotion by setae: Phylum Annelida
(c) Body perforated with numerous pores: Phylum Porifera

OR
Differences between bony fish and cartilaginous fish:

Bony fish Cartilaginous fish
1. Bony endoskeleton 1. Cartilaginous endoskeleton
2. Contain four pairs of gill slits 2. Contain five–seven pairs of gill
slits
3. Mouth is terminal 3. Mouth is ventral
4. Caudal fin is homocercal 4. Caudal fin is heterocercal
6. Examples: Sea horse, carp 6. Examples: Electric ray, sting ray

8.
(i) To make the net force a balanced force, 10 N must be added to F1.
20 N + 10 N = 30 N
(ii) To move the object along the direction of F1, it has to be exceeded by 20 N so that it
becomes greater than F2.  So, now F1 becomes 40 N.
(iii) After carrying out the condition given in question (ii),
F = 40 N
So, net force = F = F1 - F2 = 40 N - 30 N = 10 N.
Acceleration F = ma
?
??
??
2
F 10 N
10
a 1 ms
10

9. The bouncing back of sound when it strikes a hard surface is called reflection of sound.
Laws of reflection:
i) The incident wave, reflected wave and normal all lie in the same plane.
ii) The angle of incidence is always equal to the angle of reflection.

OR

CBSE IX | SCIENCE
Sample Paper – 5 Solution

SONAR stands for Sound Navigation And Ranging.
It is a device used to measure the distance, the direction and the speed of the objects
lying under water using ultrasonic waves.
It comprises a transmitter and a receiver. Powerful pulses of ultrasound waves are sent
out at regular intervals from a transmitter mounted on a ship. When these pulses are
intercepted by submerged objects, they are reflected. The reflected sound or echo is
detected by an underwater receiver, which is also mounted on the ship.
If t = time interval between transmission and reception of reflected ultrasound waves,
v = speed of sound through water,
d = distance of the object that reflected the ultrasound, then
Distance = speed × time
In time interval ‘t’, the sound waves travel twice, i.e. 2d
2d = vt
? d = v t /2
This gives the distance of the object lying under water.
10.
(a) The following factors need to be considered for fish culture:
? Topography or location of the pond
? Water resources and quality
? Soil quality
? Water temperature
(b) In composite fish culture, five or six different species of fish are grown together in a
single fishpond. Fish with different food habitats are chosen so that they do not
compete for food among themselves. For example, catla feed on the surface of water,
rohu are middle zone feeders, mrigal and common carp are bottom feeders, and
grass carp feed on weeds. This ensures complete utilisation of food resources in the
pond. Such a system increases the fish yield.

11. Snakes and turtles possess the following common features:
(a) Skin without glands
(b) Three-chambered heart
(c) Respiration through lungs
(d) Cold-blooded
(e) Hard-shelled eggs
(f) Embryo protected by extra embryonic membranes
Since snakes and turtles share the above common features, they are both grouped
under the same Class Reptilia of Phylum Chordata.

12.
Page 4

CBSE IX | SCIENCE
Sample Paper – 5 Solution

CBSE
Class IX Science
Sample Paper – 5 Solution

Section A
1. Rhizobium leguminosarum

2. Crop rotation

Section B
3. i) When an object exerts a force on another object, the second object exerts an equal
and opposite force on the first object.
ii) The third law of motion also holds true for the force of gravitation, i.e. when the
Earth exerts a force of attraction on an object, the object exerts the same force on the
Earth in the opposite direction.
OR

(i) Force constant
(ii) Gravitational

4. Particles which constitute the nucleus are called nucleons.
Protons and neutrons are the nucleons.
Atomic number of sodium is 11.
Atomic mass of sodium is 23.
No. of neutrons = 23 - 11 = 12
No. of nucleons = 23

5.
? In animals, subcutaneous fat functions as an insulating layer which prevents heat
loss from the body in the cold environment.
? So, animals in colder regions possess a thicker layer of adipose tissue to insulate
their body against the extreme cold.
? Fat also acts as a source of reserve food during periods of food scarcity.

CBSE IX | SCIENCE
Sample Paper – 5 Solution

Section C
6.
(a) Vacuole
(b) Golgi apparatus/Golgi body
(c) Mitochondria
7.
(a) Jointed appendages: Phylum Arthropoda
(b) Locomotion by setae: Phylum Annelida
(c) Body perforated with numerous pores: Phylum Porifera

OR
Differences between bony fish and cartilaginous fish:

Bony fish Cartilaginous fish
1. Bony endoskeleton 1. Cartilaginous endoskeleton
2. Contain four pairs of gill slits 2. Contain five–seven pairs of gill
slits
3. Mouth is terminal 3. Mouth is ventral
4. Caudal fin is homocercal 4. Caudal fin is heterocercal
6. Examples: Sea horse, carp 6. Examples: Electric ray, sting ray

8.
(i) To make the net force a balanced force, 10 N must be added to F1.
20 N + 10 N = 30 N
(ii) To move the object along the direction of F1, it has to be exceeded by 20 N so that it
becomes greater than F2.  So, now F1 becomes 40 N.
(iii) After carrying out the condition given in question (ii),
F = 40 N
So, net force = F = F1 - F2 = 40 N - 30 N = 10 N.
Acceleration F = ma
?
??
??
2
F 10 N
10
a 1 ms
10

9. The bouncing back of sound when it strikes a hard surface is called reflection of sound.
Laws of reflection:
i) The incident wave, reflected wave and normal all lie in the same plane.
ii) The angle of incidence is always equal to the angle of reflection.

OR

CBSE IX | SCIENCE
Sample Paper – 5 Solution

SONAR stands for Sound Navigation And Ranging.
It is a device used to measure the distance, the direction and the speed of the objects
lying under water using ultrasonic waves.
It comprises a transmitter and a receiver. Powerful pulses of ultrasound waves are sent
out at regular intervals from a transmitter mounted on a ship. When these pulses are
intercepted by submerged objects, they are reflected. The reflected sound or echo is
detected by an underwater receiver, which is also mounted on the ship.
If t = time interval between transmission and reception of reflected ultrasound waves,
v = speed of sound through water,
d = distance of the object that reflected the ultrasound, then
Distance = speed × time
In time interval ‘t’, the sound waves travel twice, i.e. 2d
2d = vt
? d = v t /2
This gives the distance of the object lying under water.
10.
(a) The following factors need to be considered for fish culture:
? Topography or location of the pond
? Water resources and quality
? Soil quality
? Water temperature
(b) In composite fish culture, five or six different species of fish are grown together in a
single fishpond. Fish with different food habitats are chosen so that they do not
compete for food among themselves. For example, catla feed on the surface of water,
rohu are middle zone feeders, mrigal and common carp are bottom feeders, and
grass carp feed on weeds. This ensures complete utilisation of food resources in the
pond. Such a system increases the fish yield.

11. Snakes and turtles possess the following common features:
(a) Skin without glands
(b) Three-chambered heart
(c) Respiration through lungs
(d) Cold-blooded
(e) Hard-shelled eggs
(f) Embryo protected by extra embryonic membranes
Since snakes and turtles share the above common features, they are both grouped
under the same Class Reptilia of Phylum Chordata.

12.

CBSE IX | SCIENCE
Sample Paper – 5 Solution

Step I:
Gram molecular weight of Al2O3 = 2 × 27 + 3 × 16 = 102 g
Hence, 102 g of Al2O3 contains = 1 mole of Al2O3

Step II:
1 mole of Al2O3 contains Al atom = 2 × N0
So, 0.0005 moles of Al2O3 will contain = 2 × 0.005 × 6.022 × 1023
= 6.022 × 10
20
atoms of Al
The number of (Al
3+
) ions present is the same as the number of Al atoms.
Number of Al
3+
ions = 6.022 × 10
20
ions

OR
(a) Calcium and oxygen
(b) Hydrogen and bromine
(c) Sodium, hydrogen, carbon and oxygen
(d) Potassium, sulphur and oxygen

13.
(i) The block of wood will float on water and a portion of it will remain submerged in
water as wood has less density than water.
(ii) The object just floats in water in such a way that its entire portion remains
submerged in it.
(iii) The glass piece sinks in water as it has more density than water.

14.
(a) Sheetal’s activity is in agreement with the law of conservation of mass.
(b) Law of conservation of mass:
The law of conservation of mass states that mass can neither be created nor be
destroyed in a chemical reaction. That is the mass of the product formed is equal to
the mass of the reactants.
(c) I like Sheetal’s method. As this method is in accordance with the law and will give
accurate results.

Page 5

CBSE IX | SCIENCE
Sample Paper – 5 Solution

CBSE
Class IX Science
Sample Paper – 5 Solution

Section A
1. Rhizobium leguminosarum

2. Crop rotation

Section B
3. i) When an object exerts a force on another object, the second object exerts an equal
and opposite force on the first object.
ii) The third law of motion also holds true for the force of gravitation, i.e. when the
Earth exerts a force of attraction on an object, the object exerts the same force on the
Earth in the opposite direction.
OR

(i) Force constant
(ii) Gravitational

4. Particles which constitute the nucleus are called nucleons.
Protons and neutrons are the nucleons.
Atomic number of sodium is 11.
Atomic mass of sodium is 23.
No. of neutrons = 23 - 11 = 12
No. of nucleons = 23

5.
? In animals, subcutaneous fat functions as an insulating layer which prevents heat
loss from the body in the cold environment.
? So, animals in colder regions possess a thicker layer of adipose tissue to insulate
their body against the extreme cold.
? Fat also acts as a source of reserve food during periods of food scarcity.

CBSE IX | SCIENCE
Sample Paper – 5 Solution

Section C
6.
(a) Vacuole
(b) Golgi apparatus/Golgi body
(c) Mitochondria
7.
(a) Jointed appendages: Phylum Arthropoda
(b) Locomotion by setae: Phylum Annelida
(c) Body perforated with numerous pores: Phylum Porifera

OR
Differences between bony fish and cartilaginous fish:

Bony fish Cartilaginous fish
1. Bony endoskeleton 1. Cartilaginous endoskeleton
2. Contain four pairs of gill slits 2. Contain five–seven pairs of gill
slits
3. Mouth is terminal 3. Mouth is ventral
4. Caudal fin is homocercal 4. Caudal fin is heterocercal
6. Examples: Sea horse, carp 6. Examples: Electric ray, sting ray

8.
(i) To make the net force a balanced force, 10 N must be added to F1.
20 N + 10 N = 30 N
(ii) To move the object along the direction of F1, it has to be exceeded by 20 N so that it
becomes greater than F2.  So, now F1 becomes 40 N.
(iii) After carrying out the condition given in question (ii),
F = 40 N
So, net force = F = F1 - F2 = 40 N - 30 N = 10 N.
Acceleration F = ma
?
??
??
2
F 10 N
10
a 1 ms
10

9. The bouncing back of sound when it strikes a hard surface is called reflection of sound.
Laws of reflection:
i) The incident wave, reflected wave and normal all lie in the same plane.
ii) The angle of incidence is always equal to the angle of reflection.

OR

CBSE IX | SCIENCE
Sample Paper – 5 Solution

SONAR stands for Sound Navigation And Ranging.
It is a device used to measure the distance, the direction and the speed of the objects
lying under water using ultrasonic waves.
It comprises a transmitter and a receiver. Powerful pulses of ultrasound waves are sent
out at regular intervals from a transmitter mounted on a ship. When these pulses are
intercepted by submerged objects, they are reflected. The reflected sound or echo is
detected by an underwater receiver, which is also mounted on the ship.
If t = time interval between transmission and reception of reflected ultrasound waves,
v = speed of sound through water,
d = distance of the object that reflected the ultrasound, then
Distance = speed × time
In time interval ‘t’, the sound waves travel twice, i.e. 2d
2d = vt
? d = v t /2
This gives the distance of the object lying under water.
10.
(a) The following factors need to be considered for fish culture:
? Topography or location of the pond
? Water resources and quality
? Soil quality
? Water temperature
(b) In composite fish culture, five or six different species of fish are grown together in a
single fishpond. Fish with different food habitats are chosen so that they do not
compete for food among themselves. For example, catla feed on the surface of water,
rohu are middle zone feeders, mrigal and common carp are bottom feeders, and
grass carp feed on weeds. This ensures complete utilisation of food resources in the
pond. Such a system increases the fish yield.

11. Snakes and turtles possess the following common features:
(a) Skin without glands
(b) Three-chambered heart
(c) Respiration through lungs
(d) Cold-blooded
(e) Hard-shelled eggs
(f) Embryo protected by extra embryonic membranes
Since snakes and turtles share the above common features, they are both grouped
under the same Class Reptilia of Phylum Chordata.

12.

CBSE IX | SCIENCE
Sample Paper – 5 Solution

Step I:
Gram molecular weight of Al2O3 = 2 × 27 + 3 × 16 = 102 g
Hence, 102 g of Al2O3 contains = 1 mole of Al2O3

Step II:
1 mole of Al2O3 contains Al atom = 2 × N0
So, 0.0005 moles of Al2O3 will contain = 2 × 0.005 × 6.022 × 1023
= 6.022 × 10
20
atoms of Al
The number of (Al
3+
) ions present is the same as the number of Al atoms.
Number of Al
3+
ions = 6.022 × 10
20
ions

OR
(a) Calcium and oxygen
(b) Hydrogen and bromine
(c) Sodium, hydrogen, carbon and oxygen
(d) Potassium, sulphur and oxygen

13.
(i) The block of wood will float on water and a portion of it will remain submerged in
water as wood has less density than water.
(ii) The object just floats in water in such a way that its entire portion remains
submerged in it.
(iii) The glass piece sinks in water as it has more density than water.

14.
(a) Sheetal’s activity is in agreement with the law of conservation of mass.
(b) Law of conservation of mass:
The law of conservation of mass states that mass can neither be created nor be
destroyed in a chemical reaction. That is the mass of the product formed is equal to
the mass of the reactants.
(c) I like Sheetal’s method. As this method is in accordance with the law and will give
accurate results.

CBSE IX | SCIENCE
Sample Paper – 5 Solution

15.

Section D
16.

(a) Features of the nuclear model of an atom by Rutherford:
? There is a positively charged centre in an atom called the nucleus. Nearly all
the mass of an atom resides in the nucleus.
? The electrons revolve around the nucleus in well-defined orbits.
? The size of the nucleus is very small as compared to the size of the atom.

(b) The maximum capacity of a shell to accommodate electrons is given by the general
formula 2n
2
, where n is the number of a shell.
The maximum number of electrons possible in the outermost shell is 8 and that in
the penultimate shell is 18.
It is not necessary for an orbit to be completed before another is formed. In fact, a
new orbit is formed when the outermost shell attains 8 electrons.

17.
(a) An increase in the concentration of carbon dioxide in the atmosphere would cause
the average temperature of the Earth to increase, leading to global warming.
(b)
(i) A biogeochemical cycle or nutrient cycle is the pathway by which a chemical
element or molecule moves through both biotic (biosphere) and abiotic
(lithosphere, atmosphere and hydrosphere) components of the Earth.
Examples of biogeochemical cycles are water cycle, nitrogen cycle, carbon cycle,
sulphur cycle and phosphorous cycle. (Any two)
Dalton's atomic theory Modern atomic theory
(i) Atoms are indivisible particles. (i) Atoms are divisible into sub-atomic
particles like protons, neutrons and
electrons.
(ii) Atoms can neither be created nor
destroyed.
(ii) Atoms can be created and destroyed by
nuclear fusion and fission.
(iii) The atoms of an element are alike in all
respect and differ from atoms of other
elements.
(iii) The atoms of an element may not be
alike in all respects, as it is seen in the case
of isotopes. Isotopes which are atoms of the
same element having the same atomic
number but different mass numbers.
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