CBSE IX SCIENCE
Sample Paper 2 - Solution
CBSE Board
Class IX Science
Term 1 Sample
Paper - 3
Time: 3 hrs
Total Marks: 90
Solution
SECTION-A
Ans1. In an open ground, the high speed of wind increases the rate of evaporation and
hence wet clothes dry up faster.
Ans2. The gravitational force between earth and the body is known as Weight of the body
or the force of gravity.
Ans3. Yes, it is possible. If another train on an adjacent line is running, then we feel that our
train is moving in the opposite direction of that train.
Ans4.
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CBSE IX SCIENCE
Sample Paper 2 - Solution
Ans5. According to II law: F = ma
Ft = mv - mu
If, F = 0, v = u
i.e., the object continues to move with uniform velocity.
If, F = 0 and u = 0, v is also 0
i.e., object will remain at rest.
This is Newton's first law of motion according to which an object at rest or uniform motion
tends to remain at rest or in uniform motion unless an unbalanced forced acts on it.
Ans6.
i. Drone
ii. Broiler
iii. Layer
iv. Indigenous species
Ans7. Cattle breed is improved by hybridization. The breeds are improved to increase
lactation period and resistance to diseases.
Ans8.
(a) Water vapour present in air on coming in contact with cold surface of glass tumbler
gets condensed to form tiny water droplets.
(b) Cotton being a good absorber of water helps in absorbing the sweat and exposing it
to atmosphere for easy evaporation causing cooling.
(c) The sprinkled water evaporates by taking large latent heat of vaporization from the
roof or open ground and surrounding air causing cooling of the place.
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Sample Paper 2 - Solution
Ans9. Two examples of compressed gases which we use in our daily lives are:
1. Liquefied petroleum gas (LPG) - The liquefied petroleum gas (LPG) cylinder that we
get in our home for cooking or the oxygen supplied to hospitals in cylinders is
compressed gas.
2. Compressed natural gas (CNG) - Compressed natural gas (CNG) is used as fuel these
days in vehicles.
Reason - Due to high compressibility, large volumes of a gas can be compressed into a small
cylinder and transported easily.
Ans10.
(a) An element is the basic form of matter that cannot be broken down into simpler
substances by usual chemical methods of applying heat, light or electric energy.
(b) Water is not considered an element because it can be split up into its two simpler
substances, hydrogen and oxygen, by electricity.
(c) An alloy is considered a mixture because:
(i) It shows the properties of its constituents.
(ii) It has a variable composition.
Ans11.
(a) The concentration of a solution is the amount of solute present in a given quantity of
the solution.
(b) Given:
Mass percentage of solution = 20%
Mass of solution = 550 g
Mass of solute = m
Since mass percentage of solution = (mass of solute/ mass of solution) X 100
Therefore, mass of solute = (mass percentage of solution x mass of solution)/ 100
Substituting the values we get
m = (20 x 550)/100
= 110 g
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Sample Paper 2 - Solution
Ans12. Properties of colloids are:
(i) They are heterogeneous mixtures.
(ii) The size of particles of colloids is too small to be seen by naked eye.
(iii) They scatter light passing through them making its path visible.
Ans13. Let a stone A is allowed to fall from top of a height h = 100m
Its initial velocity u1 = 0
And a1 = +g = +10 ms-2
Another stone B is projected upwards from the ground with an initial velocity u 2 = 25ms-1
and for it a2 = -g = -10 ms-2
Let the two stones meet at a point C at a distance y below A or (100-y) above B after a time
t.
Then for stone A
For stone B
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Sample Paper 2 - Solution
Ans14.
Ans15.
Negative sign indicates that, it is an opposing force.
Ans16. Every object in this universe attracts every other object with a force which is
directly proportional to the product of their masses and inversely proportional to the
square of the distance between their centres. The direction of force is along the line joining
the centres of two objects.
Consider two bodies A and B of masses M and m respectively and’d’ is the distance between
then centres. Let F be the force by which they mutually attract each other
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Sample Paper 2 - Solution
Ans17.
Plant cell
(i) Cell wall is
present.
(ii) Plastids are
present.
Animal cell
(i) Cell wall is absent.
(ii) Plastids are absent.
(iii) Numerous small
vacuoles are
(iii) A single large
vacuole is present at
the centre.
Ans18.
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Ans19.
(a) Pesticides are non-biodegradable so they remain in soil, water as well as plants.
They enter the food chain and harm the human beings and other animals.
(b) Farmers should use biological methods to control pests as they do not cause any
environmental pollution. As possible, farmers should avoid the use of pesticides. It is
our responsibility to keep our environment pollution free.
Ans20. (a) % of solution = 5
Mass of solution = 250g
(b) Dispersed phase - the solute like component in a colloid form the dispersed phase.
Dispersed medium - the component in which the dispersed phase is suspended is the
dispersed medium
Or
(a) Mass of solute = 36 g, Mass of solvent = 100g, Mass of solution = 100 + 36 = 136g
Concentration of solution = (Mass of solute / Mass of solution) x 100
= (36/136) x 100 = 26.47%
(b) If temperature increases, solubility increases and if temperature decreases, solubility
decreases.
(c) Because particle size is bigger in suspensions hence it is easier to distinguish the
particles of solute.
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Sample Paper 2 - Solution
Ans21.
Or
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Sample Paper 2 - Solution
Ans22. First Law of Motion- A body continues to be in a state of rest or in a state of uniform
motion along a straight line; unless an external force is applied on the body to change the
state.
Third Law of Motion- To every action, there is always an equal and opposite reaction and
they act on two different bodies.
or
a) Second law of motion - The rate of change of linear momentum of a body is directly
proportional to the external force applied on the body, and this change takes place always
in the direction of the applied force.
One Newton force is that much force which produces an acceleration of 1m/s2 in a body of
mass one kilogram.
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Sample Paper 2 - Solution
(b) Law of conservation of momentum - The sum of momentum of the two objects before
collision is equal to the sum of momentum after the collision provided there is no external
unbalanced force acting on them.
Recoil of a gun:
Let m1=mass of shell, m2=mass of gun
Before firing, both the gun and the shell are at rest, therefore total momentum of bullet and
shell = 0
On firing, let v1=velocity of shell, v2=velocity of gun
Total momentum on firing = m1v1 + m2v2
Applying law of conservation of momentum,
m1v1 + m2v2 = 0
Negative sign shows that v2 is in a direction opposite to v1, i.e., the gun recoils when the
shell moves forward.
As m2>>m1, therefore v2<<v1, i.e., as the gun is much heavier than the bullet, the recoil
velocity of the gun is much smaller than the velocity of the bullet.
Ans23.
(a) When a living plant cell is kept in hypertonic solution, it loses water through
osmosis, so there is shrinkage of the contents of the cell away from cell wall. The
phenomenon is known as plasmolysis.
(b) Passage of water from a region of its higher concentration to the region of its lower
concentration through a semi permeable membrane is known as osmosis.
(c) The process in which lipids and proteins are used for making new cell membrane is
called membrane biogenesis.
(d) The process in which unicellular organism like Amoeba engulfs food particle by
producing pseudopodia around it is called endocytosis.
(e) When a plasmolysed cell is placed in water or hypotonic solution, it absorbs water
and contents of the cell swell up, the condition is termed as deplasmolysis.
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Sample Paper 2 - Solution
Or
(a)
(b) Nucleus is covered by double porous nuclear membrane. It has entangled mass of
thread-like structures called chromatin material. It has nucleolus and nucleoplasm.
Chromatin fibres get changed into prominent rod-shaped chromosomes during the cell
division process. Chromosomes are made of DNA and proteins. Functional segments of
DNA are called genes. DNA contains the information for constructing and organising cells.
(c)
(i) Nucleus controls all the chemical activities of the cell.
(ii) Nucleus plays an important role in cellular reproduction. It transfers characters
from parent cell to daughter cell through genes.
Ans24.
a. Chemicals which are used to kill pests, fungi, weeds and rodents are called
pesticides.
b. Excessive use of pesticides creates problems, since they can be poisonous to many
plant and animal species and cause environmental pollution.
c. Use of resistant varieties and summer ploughing.
d. Prior to sowing of the crop seeds, some plants like sun hemp or guar are grown and
then mulched by ploughing them into the soil.
Green manure helps in enriching the soil with nitrogen and phosphorous.
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Sample Paper 2 - Solution
Or
Irrigation is important to ensure that crops get water at the right stages during growing.
The different kinds of irrigation systems adopted to supply water to agricultural lands are:
(i) Wells- There are two types of wells, dug wells and tube wells. In a dug well, water is
collected from water bearing strata. Tube wells can tap water from the deeper
strata.
(ii) Canals- This is an elaborate and extensive irrigation system. In this system, canals
receive water from one or more reservoirs or from rivers.
(iii) River Lift system- In areas where canal flow is insufficient or irregular due to
inadequate reservoir release, the lift system is more rational.
(iv) Tanks- These are small storage reservoirs, which intercept and store the run-off of
smaller catchment areas.
Section B
Ans25. Copper sulphate gives a blue coloured solution since it is a coloured salt whereas
barium chloride and sodium chloride are white salts and sugar solution is transparent.
Ans26. A translucent mixture is formed since egg white forms a colloid with water.
Ans27. The mixture gives a transparent solution since sand being insoluble in water
separates out giving a clear solution of water.
Ans28. C; the thermometer must be dipped in the water level and should be close to the
middle of the water level.
Ans29. Common salt and water since common salt completely dissolves in water to form a
true solution.
Ans30. Volatile solids from non - volatile solids since on heating the volatile solid will
sublime and get converted to gaseous state leaving behind the non-volatile solid.
Ans31. Milk churned with water since milk and water both are in liquid state.
Ans32. By heating iron filings with sulphur
Fe + S
FeS
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Sample Paper 2 - Solution
Ans33. Action and reaction forces are equal in magnitude but opposite in direction.
Ans34. Rockets work on the principle of Newton's third law of motion.
Ans35. The dead sclerenchyma provides mechanical strength to the plant.
Ans36. All these are the characteristics of plant cells.
Ans37.



A is axon which is long, single, tube like structure.
B is dendrite which is hair like structure arising from the cell body.
C is cytoplasm which is filled in the cell body.
Ans38. Because potato extract is starch which turns black when iodine solution is poured
over it.
Ans39. Different stains are used to stain the cells to highlight the cell organelles.
Ans40. Striated muscle fibres have long, cylindrical cells with striations i.e. light and dark
bands.
Ans41. Sclerenchyma cells have thickened, hard and lignified walls.
Ans42. Because HCl reacts with metanil yellow to produce pink colour.
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