Final Exam Class 9 Science Set 1 (Solutions) | Science Class 9 PDF Download

 Page 1


Section A
1. 
(b) III 
Explanation: The bulb of the thermometer should be dipped in crushed ice to determine the melting point of ice.  
2. 
(d) endocytosis 
Explanation: The cell membranes flexibility allows the cell engulf in food and other material from its external environment.
This process is known as endocytosis.  
3. 
(d) Vector 
Explanation: Any quantity that needs to be fully described by identifying its magnitude and direction is referred to as a vector
quantity. By magnitude, we mean the size of the quantity, such as length or strength. By direction, we mean where the vector is
pointing or where it is being directed, such as left or right, north, south, east, or west, or even up or down.  
4. 
(d) Catla 
Explanation: Catla is the fastest growing Indian major carp species and widely distributed throughout India, Nepal, Pakistan,
Burma, and Bangladesh.  
5. 
(d) tendons 
Explanation: Each nerve cell or neuron Is composed of three parts
i. Cyton or cell body It contains central nucleus and cytoplasm with characteristic deeply stained particles called Nissl’s
granules (i.e., clumps of ribosome).
ii. Dendron These are short processes arising from cyton and further branching into dendrites.
iii. Axon It is a single long cylindrical process of uniform diameter which forms fine branches terminally. The dendrites
receives impulses and the axon takes impulses away from the cell body.
6. 
(b) The part labelled ‘a’ is the site of dark reaction. 
Explanation: The given figure is of chloroplast. The part labelled ‘a’ is stroma. The part labelled ‘b’ is called grana where
light reaction of photosynthesis takes place. The part labelled ‘c’ is intergranal thylakoid. Photosynthetic pigments such as
chlorophyll are present only in thylakoid membranes (grana + intergranal thylakoids) and not in stroma or nongranal
thylakoids.  
7. 
(d) a = multiply by 22.4 L, b = divide by 22.4 L 
Explanation: V olume of gas at STP = No. of moles  
No. of moles = Volume of gas at STP   
8. 
(c) thick and thin 
Explanation: Smooth muscle consists of thick and thin filaments that are not arranged into sarcomeres giving it a non-striated
pattern.  
9. 
(b)
1.8
× 2 2 . 4   L ? ? ? ? ? ? ? ? ? ? a ÷ 2 2 . 4   L ? ? ? ? ? ? ? ? ? ? b Solution
Page 9 of 16
Page 2


Section A
1. 
(b) III 
Explanation: The bulb of the thermometer should be dipped in crushed ice to determine the melting point of ice.  
2. 
(d) endocytosis 
Explanation: The cell membranes flexibility allows the cell engulf in food and other material from its external environment.
This process is known as endocytosis.  
3. 
(d) Vector 
Explanation: Any quantity that needs to be fully described by identifying its magnitude and direction is referred to as a vector
quantity. By magnitude, we mean the size of the quantity, such as length or strength. By direction, we mean where the vector is
pointing or where it is being directed, such as left or right, north, south, east, or west, or even up or down.  
4. 
(d) Catla 
Explanation: Catla is the fastest growing Indian major carp species and widely distributed throughout India, Nepal, Pakistan,
Burma, and Bangladesh.  
5. 
(d) tendons 
Explanation: Each nerve cell or neuron Is composed of three parts
i. Cyton or cell body It contains central nucleus and cytoplasm with characteristic deeply stained particles called Nissl’s
granules (i.e., clumps of ribosome).
ii. Dendron These are short processes arising from cyton and further branching into dendrites.
iii. Axon It is a single long cylindrical process of uniform diameter which forms fine branches terminally. The dendrites
receives impulses and the axon takes impulses away from the cell body.
6. 
(b) The part labelled ‘a’ is the site of dark reaction. 
Explanation: The given figure is of chloroplast. The part labelled ‘a’ is stroma. The part labelled ‘b’ is called grana where
light reaction of photosynthesis takes place. The part labelled ‘c’ is intergranal thylakoid. Photosynthetic pigments such as
chlorophyll are present only in thylakoid membranes (grana + intergranal thylakoids) and not in stroma or nongranal
thylakoids.  
7. 
(d) a = multiply by 22.4 L, b = divide by 22.4 L 
Explanation: V olume of gas at STP = No. of moles  
No. of moles = Volume of gas at STP   
8. 
(c) thick and thin 
Explanation: Smooth muscle consists of thick and thin filaments that are not arranged into sarcomeres giving it a non-striated
pattern.  
9. 
(b)
1.8
× 2 2 . 4   L ? ? ? ? ? ? ? ? ? ? a ÷ 2 2 . 4   L ? ? ? ? ? ? ? ? ? ? b Solution
Page 9 of 16
Explanation: V olume of block = change in level by volume = (4.2 – 2.4) = 1.8 cm
3
  
10. 
(b)  
Explanation: Velocity increases from 0 to v: 
We know that v = u + at 
Here, u = 0, v = v, a =   t =  
and s = ut +  at
2
; s
1 
=  
Velocity decreases from v to 0: 
Here, u = v, v = 0, a = - 
Using v = u + at 
 t =  
and s = ut + at
2
; s
2
 =  
So, distance travelled during acceleration and retardation, 
d = s
1
 + s
2
 =  
Thus, distance travelled during constant velocity 
S
3
 = L - 
So, time taken to travel this distance 
 =  -  
Hence, total time taken to cover distance L 
=  +  +  
=  +   
11. 
(c) 60 
Explanation: Maximum number of electrons in K-shell i.e. 1st shell = 2 
Maximum number of electrons in L-shell = 8 
Maximum number of electrons in M-shell = 18 
Maximum number of electrons in N-shell = 32 
2 + 8 + 18 + 32 = 60  
12. 
(b) inner side of cheek with a toothpick 
Explanation: While preparing a mount of human cheek cell, the sample is collected from the inner side of the cheek using a
toothpick, which will collect some cheek cells.  
13. 
(b) shrinkage of cytoplasm in hypertonic medium 
Explanation: Plasmolysis is mainly known as shrinking of cell membrane in hypertonic solution and great pressure.  
14. 
(b) All statements are correct 
Explanation: Some of the characteristics of a physical change are:
i. Temporary in nature.
ii. No energy change occur.
iii. Does not affect the internal structure of a substance, only the molecules are rearranged.
iv. No new substance is formed.
So all statements are correct.
15. (a) I, II, III and IV 
Explanation: I, II, III and IV
+ L v v 2 ( + ) 1 a 1 ß a ? v a 1 2 v 2 2 a ß ? v ß 1 2 v 2 2 ß  ( + ) v 2 2 1 a 1 ß  ( + ) v 2 2 1 a 1 ß t = L - ( + ) v 2 2 1 a 1 ß v L v v 2 ( + ) 1 a 1 ß ( ) v a [ - ( + ) ] L v v 2 1 a 1 ß ( ) v ß L v 2 v ( + ) 1 a 1 ß Page 10 of 16
Page 3


Section A
1. 
(b) III 
Explanation: The bulb of the thermometer should be dipped in crushed ice to determine the melting point of ice.  
2. 
(d) endocytosis 
Explanation: The cell membranes flexibility allows the cell engulf in food and other material from its external environment.
This process is known as endocytosis.  
3. 
(d) Vector 
Explanation: Any quantity that needs to be fully described by identifying its magnitude and direction is referred to as a vector
quantity. By magnitude, we mean the size of the quantity, such as length or strength. By direction, we mean where the vector is
pointing or where it is being directed, such as left or right, north, south, east, or west, or even up or down.  
4. 
(d) Catla 
Explanation: Catla is the fastest growing Indian major carp species and widely distributed throughout India, Nepal, Pakistan,
Burma, and Bangladesh.  
5. 
(d) tendons 
Explanation: Each nerve cell or neuron Is composed of three parts
i. Cyton or cell body It contains central nucleus and cytoplasm with characteristic deeply stained particles called Nissl’s
granules (i.e., clumps of ribosome).
ii. Dendron These are short processes arising from cyton and further branching into dendrites.
iii. Axon It is a single long cylindrical process of uniform diameter which forms fine branches terminally. The dendrites
receives impulses and the axon takes impulses away from the cell body.
6. 
(b) The part labelled ‘a’ is the site of dark reaction. 
Explanation: The given figure is of chloroplast. The part labelled ‘a’ is stroma. The part labelled ‘b’ is called grana where
light reaction of photosynthesis takes place. The part labelled ‘c’ is intergranal thylakoid. Photosynthetic pigments such as
chlorophyll are present only in thylakoid membranes (grana + intergranal thylakoids) and not in stroma or nongranal
thylakoids.  
7. 
(d) a = multiply by 22.4 L, b = divide by 22.4 L 
Explanation: V olume of gas at STP = No. of moles  
No. of moles = Volume of gas at STP   
8. 
(c) thick and thin 
Explanation: Smooth muscle consists of thick and thin filaments that are not arranged into sarcomeres giving it a non-striated
pattern.  
9. 
(b)
1.8
× 2 2 . 4   L ? ? ? ? ? ? ? ? ? ? a ÷ 2 2 . 4   L ? ? ? ? ? ? ? ? ? ? b Solution
Page 9 of 16
Explanation: V olume of block = change in level by volume = (4.2 – 2.4) = 1.8 cm
3
  
10. 
(b)  
Explanation: Velocity increases from 0 to v: 
We know that v = u + at 
Here, u = 0, v = v, a =   t =  
and s = ut +  at
2
; s
1 
=  
Velocity decreases from v to 0: 
Here, u = v, v = 0, a = - 
Using v = u + at 
 t =  
and s = ut + at
2
; s
2
 =  
So, distance travelled during acceleration and retardation, 
d = s
1
 + s
2
 =  
Thus, distance travelled during constant velocity 
S
3
 = L - 
So, time taken to travel this distance 
 =  -  
Hence, total time taken to cover distance L 
=  +  +  
=  +   
11. 
(c) 60 
Explanation: Maximum number of electrons in K-shell i.e. 1st shell = 2 
Maximum number of electrons in L-shell = 8 
Maximum number of electrons in M-shell = 18 
Maximum number of electrons in N-shell = 32 
2 + 8 + 18 + 32 = 60  
12. 
(b) inner side of cheek with a toothpick 
Explanation: While preparing a mount of human cheek cell, the sample is collected from the inner side of the cheek using a
toothpick, which will collect some cheek cells.  
13. 
(b) shrinkage of cytoplasm in hypertonic medium 
Explanation: Plasmolysis is mainly known as shrinking of cell membrane in hypertonic solution and great pressure.  
14. 
(b) All statements are correct 
Explanation: Some of the characteristics of a physical change are:
i. Temporary in nature.
ii. No energy change occur.
iii. Does not affect the internal structure of a substance, only the molecules are rearranged.
iv. No new substance is formed.
So all statements are correct.
15. (a) I, II, III and IV 
Explanation: I, II, III and IV
+ L v v 2 ( + ) 1 a 1 ß a ? v a 1 2 v 2 2 a ß ? v ß 1 2 v 2 2 ß  ( + ) v 2 2 1 a 1 ß  ( + ) v 2 2 1 a 1 ß t = L - ( + ) v 2 2 1 a 1 ß v L v v 2 ( + ) 1 a 1 ß ( ) v a [ - ( + ) ] L v v 2 1 a 1 ß ( ) v ß L v 2 v ( + ) 1 a 1 ß Page 10 of 16
16. 
(c) Eutrophication 
Explanation: The enrichment of water bodies with nutrients leading to excessive growth of phytoplankton is called
Eutrophication. Eutrophication or more precisely hypertrophication, is the enrichment of a water body with nutrients,
usually with an excess amount of nutrients. This process induces the growth of plants and algae and due to the biomass load,
may result in oxygen depletion of the water body.
Eutrophication is an enrichment of water by nutrient salts that causes structural changes to the ecosystem such as increased
production of algae and aquatic plants, depletion of fish species, general deterioration of water quality, and other effects that
reduce and preclude use. Eutrophication is almost always induced by the discharge of phosphate-containing detergents,
fertilizers, or sewage into an aquatic system.  
17. 
(c) A is true but R is false. 
Explanation: A body has a uniform acceleration if it travels in a straight line and its velocity increases by equal amounts in
equal intervals of time.  
18. (a) Both A and R are true and R is the correct explanation of A. 
Explanation: As the particles of solids are closely packed, there exist strong forces of attraction between the particles. Hence,
solids do not diffuse in air.
19. 
(b) Both A and R are true but R is not the correct explanation of A. 
Explanation: The vessel is a long-distance channel for water transport. A Sieve tube is a long-distance channel for the
transport of organic nutrients. The wall of the vessel is lignified. Lignification is absent in sieve tubes.  
20. 
(b) Both A and R are true but R is not the correct explanation of A. 
Explanation: Atom is electrically neutral because the number of protons (positively charged particle) is equal to the number of
electrons (negatively charged particle).  
Section B
21. When a satellite moves around the Earth in a circular path, then the force of gravity acts on it directed towards the centre. The
motion of the satellite is in the horizontal plane. Therefore, the force of gravity of Earth on the satellite and the direction of motion
of satellite are perpendicular to each other. Therefore, net work done = Fs cos 900 = 0. That is, the work done by the force of
gravity on a satellite moving around the Earth is zero.
OR
The boy has to overcome the force of gravity. Hence force of gravity on the boy 
F = mg = 40 × 9.8 = 392 N 
Total distance covered s = 50 × 10 = 500 cm = 5 m 
i) Work done by the body in climbing = force × distance = W = 392 × 5 = 1960 J 
ii) Power developed =  = 392 W
22. Substance undergo change in physical state because both inter-particle spaces and inter-particle forces can be changed by
changing the conditions of temperature and pressure.
23. Three features of transverse waves are:
i. The particles of the medium vibrate at right angles to the direction of propagation of the wave.
ii. Transverse waves travel in the form of crests and troughs.
iii. They cannot travel through a vacuum.
24. Once the change of state of a substance begins or starts, the energy which is now supplied is being used up as latent heat. It means
that it does not increase the kinetic energy of the particles and is used up only to bring about a change in state. Therefore the
temperature becomes constant. Once the state is changed, the kinetic energy starts increasing.
25. In a car accident, a fast running car stops suddenly. Due to this the car’s large momentum is reduced to zero in a very short time.
The stretchable seat belts tightened by the passengers of the car increases the time taken by the passengers to fall forward. Due to
long time, the rate change of momentum of passengers is reduced and hence less stopping force acts on them. So, the passengers
may either not get injured at all or may get less injuries. It is obvious that seat belts reduce the passengers’ momentum more
gently and hence prevent injuries.
OR
= W t 1 9 6 0 5 Page 11 of 16
Page 4


Section A
1. 
(b) III 
Explanation: The bulb of the thermometer should be dipped in crushed ice to determine the melting point of ice.  
2. 
(d) endocytosis 
Explanation: The cell membranes flexibility allows the cell engulf in food and other material from its external environment.
This process is known as endocytosis.  
3. 
(d) Vector 
Explanation: Any quantity that needs to be fully described by identifying its magnitude and direction is referred to as a vector
quantity. By magnitude, we mean the size of the quantity, such as length or strength. By direction, we mean where the vector is
pointing or where it is being directed, such as left or right, north, south, east, or west, or even up or down.  
4. 
(d) Catla 
Explanation: Catla is the fastest growing Indian major carp species and widely distributed throughout India, Nepal, Pakistan,
Burma, and Bangladesh.  
5. 
(d) tendons 
Explanation: Each nerve cell or neuron Is composed of three parts
i. Cyton or cell body It contains central nucleus and cytoplasm with characteristic deeply stained particles called Nissl’s
granules (i.e., clumps of ribosome).
ii. Dendron These are short processes arising from cyton and further branching into dendrites.
iii. Axon It is a single long cylindrical process of uniform diameter which forms fine branches terminally. The dendrites
receives impulses and the axon takes impulses away from the cell body.
6. 
(b) The part labelled ‘a’ is the site of dark reaction. 
Explanation: The given figure is of chloroplast. The part labelled ‘a’ is stroma. The part labelled ‘b’ is called grana where
light reaction of photosynthesis takes place. The part labelled ‘c’ is intergranal thylakoid. Photosynthetic pigments such as
chlorophyll are present only in thylakoid membranes (grana + intergranal thylakoids) and not in stroma or nongranal
thylakoids.  
7. 
(d) a = multiply by 22.4 L, b = divide by 22.4 L 
Explanation: V olume of gas at STP = No. of moles  
No. of moles = Volume of gas at STP   
8. 
(c) thick and thin 
Explanation: Smooth muscle consists of thick and thin filaments that are not arranged into sarcomeres giving it a non-striated
pattern.  
9. 
(b)
1.8
× 2 2 . 4   L ? ? ? ? ? ? ? ? ? ? a ÷ 2 2 . 4   L ? ? ? ? ? ? ? ? ? ? b Solution
Page 9 of 16
Explanation: V olume of block = change in level by volume = (4.2 – 2.4) = 1.8 cm
3
  
10. 
(b)  
Explanation: Velocity increases from 0 to v: 
We know that v = u + at 
Here, u = 0, v = v, a =   t =  
and s = ut +  at
2
; s
1 
=  
Velocity decreases from v to 0: 
Here, u = v, v = 0, a = - 
Using v = u + at 
 t =  
and s = ut + at
2
; s
2
 =  
So, distance travelled during acceleration and retardation, 
d = s
1
 + s
2
 =  
Thus, distance travelled during constant velocity 
S
3
 = L - 
So, time taken to travel this distance 
 =  -  
Hence, total time taken to cover distance L 
=  +  +  
=  +   
11. 
(c) 60 
Explanation: Maximum number of electrons in K-shell i.e. 1st shell = 2 
Maximum number of electrons in L-shell = 8 
Maximum number of electrons in M-shell = 18 
Maximum number of electrons in N-shell = 32 
2 + 8 + 18 + 32 = 60  
12. 
(b) inner side of cheek with a toothpick 
Explanation: While preparing a mount of human cheek cell, the sample is collected from the inner side of the cheek using a
toothpick, which will collect some cheek cells.  
13. 
(b) shrinkage of cytoplasm in hypertonic medium 
Explanation: Plasmolysis is mainly known as shrinking of cell membrane in hypertonic solution and great pressure.  
14. 
(b) All statements are correct 
Explanation: Some of the characteristics of a physical change are:
i. Temporary in nature.
ii. No energy change occur.
iii. Does not affect the internal structure of a substance, only the molecules are rearranged.
iv. No new substance is formed.
So all statements are correct.
15. (a) I, II, III and IV 
Explanation: I, II, III and IV
+ L v v 2 ( + ) 1 a 1 ß a ? v a 1 2 v 2 2 a ß ? v ß 1 2 v 2 2 ß  ( + ) v 2 2 1 a 1 ß  ( + ) v 2 2 1 a 1 ß t = L - ( + ) v 2 2 1 a 1 ß v L v v 2 ( + ) 1 a 1 ß ( ) v a [ - ( + ) ] L v v 2 1 a 1 ß ( ) v ß L v 2 v ( + ) 1 a 1 ß Page 10 of 16
16. 
(c) Eutrophication 
Explanation: The enrichment of water bodies with nutrients leading to excessive growth of phytoplankton is called
Eutrophication. Eutrophication or more precisely hypertrophication, is the enrichment of a water body with nutrients,
usually with an excess amount of nutrients. This process induces the growth of plants and algae and due to the biomass load,
may result in oxygen depletion of the water body.
Eutrophication is an enrichment of water by nutrient salts that causes structural changes to the ecosystem such as increased
production of algae and aquatic plants, depletion of fish species, general deterioration of water quality, and other effects that
reduce and preclude use. Eutrophication is almost always induced by the discharge of phosphate-containing detergents,
fertilizers, or sewage into an aquatic system.  
17. 
(c) A is true but R is false. 
Explanation: A body has a uniform acceleration if it travels in a straight line and its velocity increases by equal amounts in
equal intervals of time.  
18. (a) Both A and R are true and R is the correct explanation of A. 
Explanation: As the particles of solids are closely packed, there exist strong forces of attraction between the particles. Hence,
solids do not diffuse in air.
19. 
(b) Both A and R are true but R is not the correct explanation of A. 
Explanation: The vessel is a long-distance channel for water transport. A Sieve tube is a long-distance channel for the
transport of organic nutrients. The wall of the vessel is lignified. Lignification is absent in sieve tubes.  
20. 
(b) Both A and R are true but R is not the correct explanation of A. 
Explanation: Atom is electrically neutral because the number of protons (positively charged particle) is equal to the number of
electrons (negatively charged particle).  
Section B
21. When a satellite moves around the Earth in a circular path, then the force of gravity acts on it directed towards the centre. The
motion of the satellite is in the horizontal plane. Therefore, the force of gravity of Earth on the satellite and the direction of motion
of satellite are perpendicular to each other. Therefore, net work done = Fs cos 900 = 0. That is, the work done by the force of
gravity on a satellite moving around the Earth is zero.
OR
The boy has to overcome the force of gravity. Hence force of gravity on the boy 
F = mg = 40 × 9.8 = 392 N 
Total distance covered s = 50 × 10 = 500 cm = 5 m 
i) Work done by the body in climbing = force × distance = W = 392 × 5 = 1960 J 
ii) Power developed =  = 392 W
22. Substance undergo change in physical state because both inter-particle spaces and inter-particle forces can be changed by
changing the conditions of temperature and pressure.
23. Three features of transverse waves are:
i. The particles of the medium vibrate at right angles to the direction of propagation of the wave.
ii. Transverse waves travel in the form of crests and troughs.
iii. They cannot travel through a vacuum.
24. Once the change of state of a substance begins or starts, the energy which is now supplied is being used up as latent heat. It means
that it does not increase the kinetic energy of the particles and is used up only to bring about a change in state. Therefore the
temperature becomes constant. Once the state is changed, the kinetic energy starts increasing.
25. In a car accident, a fast running car stops suddenly. Due to this the car’s large momentum is reduced to zero in a very short time.
The stretchable seat belts tightened by the passengers of the car increases the time taken by the passengers to fall forward. Due to
long time, the rate change of momentum of passengers is reduced and hence less stopping force acts on them. So, the passengers
may either not get injured at all or may get less injuries. It is obvious that seat belts reduce the passengers’ momentum more
gently and hence prevent injuries.
OR
= W t 1 9 6 0 5 Page 11 of 16
Mass of stone (m) = 1 kg 
Initial velocity of stone (u) = 20 ms
-1
 
Final velocity of stone (v) = 0 
Distance covered by the stone (s) = 50 m 
Acceleration of stone (a) = ? 
Force acting on the stone due to friction (F) =? 
We know;  
v
2
 - u
2
 = 2as 
(0)
2
 - (20)
2
 = 2a  50 
- 400 = 100 a 
a  = -4 
a = - 4 ms
-2
 
Force of friction (F) = ma 
= 1  (-4) 
= - 4 N 
Negative sign signifies that force of friction is acting in the direction opposite to the direction of motion of the stone.
26. Mass number of helium is equal to its atomic mass but has no units.
 Mass number (A) of helium = 4 
No. of protons in the nucleus = 2 
Number of neutron = Mass number – number of proton = 4– 2 = 2
Section C
27. 
Wavelength is the distance between two consecutive compressions or two consecutive rarefactions of a wave sound. Wavelength
is represented by the Greek letter  (lambda). The SI unit of wavelength is metre (m). 
Time period is the time taken to travel the distance between any two consecutive compression or rarefaction from a fixed point.
The time period of a sound wave is represented by letter ‘T’. The SI unit of time period is second (s).
28. The mass number of X = Number of protons + Number of neutrons = 6 + 6 = 12 
The mass number of Y = Number of protons + Number of neutrons = 6 + 8 = 14 
Since the number of protons (6) in the two species is the same and the atomic mass of the two species is different (12 and 14), the
given atomic species are isotopes of the same element (with atomic number Z = 6).
i. 29. Position – time 
× = - 4 0 0 1 0 0 × ? ? Page 12 of 16
Page 5


Section A
1. 
(b) III 
Explanation: The bulb of the thermometer should be dipped in crushed ice to determine the melting point of ice.  
2. 
(d) endocytosis 
Explanation: The cell membranes flexibility allows the cell engulf in food and other material from its external environment.
This process is known as endocytosis.  
3. 
(d) Vector 
Explanation: Any quantity that needs to be fully described by identifying its magnitude and direction is referred to as a vector
quantity. By magnitude, we mean the size of the quantity, such as length or strength. By direction, we mean where the vector is
pointing or where it is being directed, such as left or right, north, south, east, or west, or even up or down.  
4. 
(d) Catla 
Explanation: Catla is the fastest growing Indian major carp species and widely distributed throughout India, Nepal, Pakistan,
Burma, and Bangladesh.  
5. 
(d) tendons 
Explanation: Each nerve cell or neuron Is composed of three parts
i. Cyton or cell body It contains central nucleus and cytoplasm with characteristic deeply stained particles called Nissl’s
granules (i.e., clumps of ribosome).
ii. Dendron These are short processes arising from cyton and further branching into dendrites.
iii. Axon It is a single long cylindrical process of uniform diameter which forms fine branches terminally. The dendrites
receives impulses and the axon takes impulses away from the cell body.
6. 
(b) The part labelled ‘a’ is the site of dark reaction. 
Explanation: The given figure is of chloroplast. The part labelled ‘a’ is stroma. The part labelled ‘b’ is called grana where
light reaction of photosynthesis takes place. The part labelled ‘c’ is intergranal thylakoid. Photosynthetic pigments such as
chlorophyll are present only in thylakoid membranes (grana + intergranal thylakoids) and not in stroma or nongranal
thylakoids.  
7. 
(d) a = multiply by 22.4 L, b = divide by 22.4 L 
Explanation: V olume of gas at STP = No. of moles  
No. of moles = Volume of gas at STP   
8. 
(c) thick and thin 
Explanation: Smooth muscle consists of thick and thin filaments that are not arranged into sarcomeres giving it a non-striated
pattern.  
9. 
(b)
1.8
× 2 2 . 4   L ? ? ? ? ? ? ? ? ? ? a ÷ 2 2 . 4   L ? ? ? ? ? ? ? ? ? ? b Solution
Page 9 of 16
Explanation: V olume of block = change in level by volume = (4.2 – 2.4) = 1.8 cm
3
  
10. 
(b)  
Explanation: Velocity increases from 0 to v: 
We know that v = u + at 
Here, u = 0, v = v, a =   t =  
and s = ut +  at
2
; s
1 
=  
Velocity decreases from v to 0: 
Here, u = v, v = 0, a = - 
Using v = u + at 
 t =  
and s = ut + at
2
; s
2
 =  
So, distance travelled during acceleration and retardation, 
d = s
1
 + s
2
 =  
Thus, distance travelled during constant velocity 
S
3
 = L - 
So, time taken to travel this distance 
 =  -  
Hence, total time taken to cover distance L 
=  +  +  
=  +   
11. 
(c) 60 
Explanation: Maximum number of electrons in K-shell i.e. 1st shell = 2 
Maximum number of electrons in L-shell = 8 
Maximum number of electrons in M-shell = 18 
Maximum number of electrons in N-shell = 32 
2 + 8 + 18 + 32 = 60  
12. 
(b) inner side of cheek with a toothpick 
Explanation: While preparing a mount of human cheek cell, the sample is collected from the inner side of the cheek using a
toothpick, which will collect some cheek cells.  
13. 
(b) shrinkage of cytoplasm in hypertonic medium 
Explanation: Plasmolysis is mainly known as shrinking of cell membrane in hypertonic solution and great pressure.  
14. 
(b) All statements are correct 
Explanation: Some of the characteristics of a physical change are:
i. Temporary in nature.
ii. No energy change occur.
iii. Does not affect the internal structure of a substance, only the molecules are rearranged.
iv. No new substance is formed.
So all statements are correct.
15. (a) I, II, III and IV 
Explanation: I, II, III and IV
+ L v v 2 ( + ) 1 a 1 ß a ? v a 1 2 v 2 2 a ß ? v ß 1 2 v 2 2 ß  ( + ) v 2 2 1 a 1 ß  ( + ) v 2 2 1 a 1 ß t = L - ( + ) v 2 2 1 a 1 ß v L v v 2 ( + ) 1 a 1 ß ( ) v a [ - ( + ) ] L v v 2 1 a 1 ß ( ) v ß L v 2 v ( + ) 1 a 1 ß Page 10 of 16
16. 
(c) Eutrophication 
Explanation: The enrichment of water bodies with nutrients leading to excessive growth of phytoplankton is called
Eutrophication. Eutrophication or more precisely hypertrophication, is the enrichment of a water body with nutrients,
usually with an excess amount of nutrients. This process induces the growth of plants and algae and due to the biomass load,
may result in oxygen depletion of the water body.
Eutrophication is an enrichment of water by nutrient salts that causes structural changes to the ecosystem such as increased
production of algae and aquatic plants, depletion of fish species, general deterioration of water quality, and other effects that
reduce and preclude use. Eutrophication is almost always induced by the discharge of phosphate-containing detergents,
fertilizers, or sewage into an aquatic system.  
17. 
(c) A is true but R is false. 
Explanation: A body has a uniform acceleration if it travels in a straight line and its velocity increases by equal amounts in
equal intervals of time.  
18. (a) Both A and R are true and R is the correct explanation of A. 
Explanation: As the particles of solids are closely packed, there exist strong forces of attraction between the particles. Hence,
solids do not diffuse in air.
19. 
(b) Both A and R are true but R is not the correct explanation of A. 
Explanation: The vessel is a long-distance channel for water transport. A Sieve tube is a long-distance channel for the
transport of organic nutrients. The wall of the vessel is lignified. Lignification is absent in sieve tubes.  
20. 
(b) Both A and R are true but R is not the correct explanation of A. 
Explanation: Atom is electrically neutral because the number of protons (positively charged particle) is equal to the number of
electrons (negatively charged particle).  
Section B
21. When a satellite moves around the Earth in a circular path, then the force of gravity acts on it directed towards the centre. The
motion of the satellite is in the horizontal plane. Therefore, the force of gravity of Earth on the satellite and the direction of motion
of satellite are perpendicular to each other. Therefore, net work done = Fs cos 900 = 0. That is, the work done by the force of
gravity on a satellite moving around the Earth is zero.
OR
The boy has to overcome the force of gravity. Hence force of gravity on the boy 
F = mg = 40 × 9.8 = 392 N 
Total distance covered s = 50 × 10 = 500 cm = 5 m 
i) Work done by the body in climbing = force × distance = W = 392 × 5 = 1960 J 
ii) Power developed =  = 392 W
22. Substance undergo change in physical state because both inter-particle spaces and inter-particle forces can be changed by
changing the conditions of temperature and pressure.
23. Three features of transverse waves are:
i. The particles of the medium vibrate at right angles to the direction of propagation of the wave.
ii. Transverse waves travel in the form of crests and troughs.
iii. They cannot travel through a vacuum.
24. Once the change of state of a substance begins or starts, the energy which is now supplied is being used up as latent heat. It means
that it does not increase the kinetic energy of the particles and is used up only to bring about a change in state. Therefore the
temperature becomes constant. Once the state is changed, the kinetic energy starts increasing.
25. In a car accident, a fast running car stops suddenly. Due to this the car’s large momentum is reduced to zero in a very short time.
The stretchable seat belts tightened by the passengers of the car increases the time taken by the passengers to fall forward. Due to
long time, the rate change of momentum of passengers is reduced and hence less stopping force acts on them. So, the passengers
may either not get injured at all or may get less injuries. It is obvious that seat belts reduce the passengers’ momentum more
gently and hence prevent injuries.
OR
= W t 1 9 6 0 5 Page 11 of 16
Mass of stone (m) = 1 kg 
Initial velocity of stone (u) = 20 ms
-1
 
Final velocity of stone (v) = 0 
Distance covered by the stone (s) = 50 m 
Acceleration of stone (a) = ? 
Force acting on the stone due to friction (F) =? 
We know;  
v
2
 - u
2
 = 2as 
(0)
2
 - (20)
2
 = 2a  50 
- 400 = 100 a 
a  = -4 
a = - 4 ms
-2
 
Force of friction (F) = ma 
= 1  (-4) 
= - 4 N 
Negative sign signifies that force of friction is acting in the direction opposite to the direction of motion of the stone.
26. Mass number of helium is equal to its atomic mass but has no units.
 Mass number (A) of helium = 4 
No. of protons in the nucleus = 2 
Number of neutron = Mass number – number of proton = 4– 2 = 2
Section C
27. 
Wavelength is the distance between two consecutive compressions or two consecutive rarefactions of a wave sound. Wavelength
is represented by the Greek letter  (lambda). The SI unit of wavelength is metre (m). 
Time period is the time taken to travel the distance between any two consecutive compression or rarefaction from a fixed point.
The time period of a sound wave is represented by letter ‘T’. The SI unit of time period is second (s).
28. The mass number of X = Number of protons + Number of neutrons = 6 + 6 = 12 
The mass number of Y = Number of protons + Number of neutrons = 6 + 8 = 14 
Since the number of protons (6) in the two species is the same and the atomic mass of the two species is different (12 and 14), the
given atomic species are isotopes of the same element (with atomic number Z = 6).
i. 29. Position – time 
× = - 4 0 0 1 0 0 × ? ? Page 12 of 16
ii. Velocity – time 
iii. Acceleration- time 
OR
a. Distance covered 
b. Displacement  
 along AB
30. In Fig. (i), the angle between F and S is , so work done is zero. 
In Fig. (ii), the angle between F and S is , so work done is positive. 
In Fig. (iii), the angle between F and S is , so work done is negative.
i. 31. Road accidents occurring due to high speeds are much worse than accidents due to low speeds of vehicles. This is because the
momentum of high-speed vehicles is more than that of the low speeds of vehicles.
ii. When a motorcar makes a sharp turn left or right at a high-speed. The lower portion of their passenger turns suddenly along
with the motorcar but your upper portion does not change its direction due to inertia. 
So, this portion of a passenger moves forward and the passenger tends to get thrown to one side or another side.
32. 
Active transport Passive transport
1. It involves movement of molecules against the concentration
gradient.
2. It requires energy in the form of ATP molecules.
3. It is a rapid movement.
4. Movement of large molecules occur by active transport.
1. It involves movement of molecules along the concentration
gradient.
2. No energy is required
3. It is a slow movement.
4. Small molecules or water molecules only are transported
passively.
OR
Mangnification of a microscope is calculated by multiplying the powers of eyepiece and objective lenses. 
Mathematically, , where P
1
 is the power of eyepiece and P
2
 is the power of objective.
33. The three main types of muscular tissues found in the human body are:
i. Skeletal (striated) muscle tissue
ii. Smooth (Non-striated) muscle tissue
iii. Cardiac muscle tissue.
= p × O A = p × 5 = 5 p c m = 2 × O B = 2 × 5 = 1 0 c m 9 0 ° 0 ° 1 8 0 ° M = × P 1 P 2 Page 13 of 16