Class 9 Science: Sample Question Paper- 4 (With Solutions) PDF Download

Class IX
Science
Sample Question Paper 2020-21
Max. Marks : 80
Duration : 3 hrs.

General Instructions:
Read the following instructions very carefully and strictly follow them : 
1. The question paper comprises four sections A, B, C and D. There are 36 questions in the question paper. All questions are compulsory.
2. Section–A – question no. 1 to 20 - all questions and parts thereof are of one mark each. These questions contain multiple choice questions (MCQs), very short answer questions and assertion - reason type questions. Answers to these questions should be given in one word or one sentence.
3. Section–B – question no. 21 to 26 are short answer type questions, carrying 2 marks each. Answers to these questions should be in the range of 30 to 50 words.
4. Section–C – question no. 27 to 33 are short answer type questions, carrying 3 marks each. Answers to these questions should be in the range of 50 to 80 words.
5. Section–D – question no. 34 to 36 are long answer type questions carrying 5 marks each. Answer to these questions should be in the range of 80 to 120 words.
6. There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions.
7. Wherever necessary, neat and properly labelled diagrams should be drawn.

Section – A

Q.1. Name the tissue which is responsible for increase in length of stem and root.   (1 Mark)
OR
What is the source of cork?  (1 Mark)
Ans. Apical meristem.
OR
Cork is obtained from the bark of a tree i.e., oak plant’s stem.

Q.2.When work done by a force is zero?  (1 Mark)
Ans. Work done by a force is zero when the direction of applied force and displacement of an object is perpendicular to each other.
W = Fscos 90° = 0

Q.3. A mixture of sulphur and carbon disulphide is
(a) Heterogeneous and shows Tyndall effect
(b) Homogeneous and shows Tyndall effect
(c) Heterogeneous and does not show Tyndall effect
(d) Homogeneous and does not show Tyndall effect
Ans. a
Solution. A mixture of sulphur and carbon disulphide is a heterogeneous colloid and shows Tyndall effect. In a colloidal solution, the particles are big enough to scatter light. This phenomenon of scattering of light by colloidal particles is known as Tyndall effect.

Q.4. Write the chemical symbol for nitrogen gas.  (1 Mark)
Ans. N₂

Q.5. What is the primary cause of haemophilia?  (1 Mark)
Ans. Primary cause of haemophilia is change in chromosome sequence.

Q.6. Write any two observation which support the fact that atoms are divisible.  (1 Mark)
Ans.  (i) Discovery of electrons and protons.
(ii) Discovery that radioactivity is nothing but disintegration of atoms.

OR
What will happen to an element ‘Z’ if its atoms gain three electrons?  (1 Mark)
Ans. It will change into trivalent anion i.e., Z^3–.

Q.7. How is gravitation different from gravity?  (1 Mark)
Ans. Gravitation is the force of attraction between any two  bodies while gravity refers to attraction between any body and the earth.

Q.8. An ant travels from P to Q and then moves from Q to R (as shown in the diagram). Show its resultant displacement in the diagram.  (1 Mark)

Ans. PR

Q.9. Name the process by which Amoeba acquires its food.  (1 Mark)
Ans. Endocytosis

OR
Define Eukaryotic cell.  (1 Mark)
Ans. A cell containing a membrane-bounded nucleus and membrane-bounded organelles is called a eukaryotic cell.

Q.10. State the energy conversions in a dry cell.  (1 Mark)
Ans. Chemical to electrical to light energy or chemical to electrical to sound energy.

Q.11. Write the formula to calculate the speed of a body moving along a circular path of radius ‘r’ when it has completed n revolutions in time t.  (1 Mark)
Ans.

OR
Give an example where object is at rest and also in motion at the same time.  (1 Mark)
Ans. A passenger travelling in a bus is at rest with respect to the fellow passengers but is in motion with respect to the surroundings.

Q.12. Name two components of chromosomes.  (1 Mark)
Ans. Proteins and DNA.

OR
Define Cell organelle.  (1 Mark)
Ans. It is a specialized sub-unit within a cell that has a specific  function, and is usually enclosed within its own membrane.

Q.13. Name the causative organism of cholera.  (1 Mark)
Ans. Vibrio cholerae.

For question numbers 14, 15 and 16, two statements are given- one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below: 
Q.14. Assertion: Cream can be separated from curd by centrifugation.
Reason: In centrifugation, immiscible liquids separate out in layers depending on their densities.  (1 Mark)
(a) Both A and R are true, and R is correct explanation of the assertion.
(b) Both A and R are true, but R is not the correct explanation of the assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.
Ans. c
Solution. Cream can be separated from curd by centrifugation. In this technique, the denser particles are forced to settle at the bottom and the lighter particles stay at the top when spun rapidly. In separating funnel technique, immiscible liquids separate

Q.15. Assertion: Influenza spreads faster.
Reason: It is an air-borne disease.   (1 Mark)
(a) Both A and R are true, and R is correct explanation of the assertion.
(b) Both A and R are true, but R is not the correct explanation of the assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.
Ans. a
Solution. Influenza is an infectious air-borne disease and hence spreads easily.

OR
Assertion: AIDS is a syndrome and not a disease.
Reason: AIDS affect many parts of the body.  (1 Mark)
(a) Both A and R are true, and R is correct explanation of the assertion.
(b) Both A and R are true, but R is not the correct explanation of the assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.
Ans. a
Solution. Disease affects only one part but syndrome affects multiple organs in our body. Hence, AIDS is a syndrome as it affects many parts like the respiratory tract etc.

Q.16. Assertion: Motion of satellites around their planets is considered an accelerated motion. 
Reason: During their motion, the speed remains constant, while the direction of motion changes continuously.  (1 Mark)
(a) Both A and R are true, and R is correct explanation of the assertion.
(b) Both A and R are true, but R is not the correct explanation of the assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.
Ans. a
Solution. Satellites revolve around their planets in almost circular orbits with constant speed. Thus, during their motion, the speed remains constant, while the direction of motion changes continuously. As a result, there is a change in their velocity. Therefore, the motion of satellites around their planets is considered as accelerated motion.

Q. No 17 - 20 contain five sub-parts each. You are expected to answer any four sub parts in these questions.

Q.17. Read the following and answer any four questions from 17 (i) to 17 (v) 
A large bus and a van, both moving with a velocity of magnitude v, have a head-on-collision and both the vehicles stop after the collision. The time of the collision is 1 sec.

(i) The vehicle, which experiences smaller force of impact is ___ .   (1 Mark)
(a) Van
(b) Bus
(c) Van and Bus both
(d) There will not be any effect on any of the vehicle
Ans. a

(ii) The vehicle, which experiences the smaller momentum change is _____.   (1 Mark)
(a) Bus
(b) Van
(c) Bus and Van both
(d) There will not be any effect on any of the vehicle
Ans. b

(iii) The vehicle, which experiences the greater acceleration is ____ .  (1 Mark)
(a) Bus and Van both
(b) Bus
(c) Van
(d) There will not be any effect on any of the vehicle
Ans. c

(iv) Which vehicle according to you will suffer the less damage?  (1 Mark)
(a) Van
(b) Bus and Van both will have similar impact
(c) Bus
(d) There will not be any effect on any of the vehicle
Ans. c

(v) If there was heavy truck in place of van, which one will be more affected?   (1 Mark)
(a) Bus
(b) Truck
(c) Bus and Truck both
(d) There will not be any effect on any of the vehicle
Ans. a

Q.18. Read the following and answer any four questions from 18 (i) to 18 (v).
Tissue ‘A’—Repairs the injured tissues and fills spaces within organs.
Tissue ‘B’—Serves as a fat reservoir and also carries out the function of insulator.

(i) Identify the animal tissues based on the given descriptions.
(a) Tissue A is adipose tissue, Tissue B is areolar tissue.
(b) Tissue A is areolar tissue, Tissue B is adipose tissue.
(c) Both are adipose tissues
(d) Both are areolar tissues.
Ans. b

(ii) The location of above tissues in human body is:

Ans. d
Solution. Location of areolar tissue: Present between the skin and muscles, around blood vessels and nerves and in bone marrow.
Location of adipose tissue: Below the skin and between internal organs. 

(iii) What will happen if cells are not organised in tissues?   (1 Mark)
(a) Various life processes will be neatly organised.
(b) All the cells in the body will function smoothly.
(c) There will be no coordination in the functioning of cells and body.
(d) There will be no effect.
Ans. c

(iv) Which of these functions throughout life without getting fatigue?   (1 Mark)
(a) Voluntary muscles
(b) Muscles of facial region
(c) Bones and cartilage
(d) Cardiac muscle
Ans. d

(v) Identify an example of animal tissue from the following :   (1 Mark)
(a) Aerenchyma
(b) Areolar tissue
(c) Meristematic tissue
(d) Chlorenchyma
Ans. b

Q.19. Read the following and answer any four questions from 19 (i) to 19 (v) 
Human beings live in societies and different localities like villages or cities, which determine the social and physical environment, both are to be kept in harmony. Public cleanliness is important for individual health. A lot of money is required for maintaining better living conditions. We need good food for healthy body and for this we have to earn more. For the treatment of diseases also, one has to be in good economic condition.

(i) What is good health?   (1 Mark)
(a) Health is a state of being well enough to function well physically, mentally and socially.
(b) Health is a state of being well enough to function well physically only, mental and social wellness is not required for it.
(c) Health is a state of being well enough to function well mentally and socially, physical fitness is not required for it.
(d) Health is a state in which a person is physically, mentally and socially disturbed.
Ans. a

(ii) Mention any three basic conditions required for good health.  (1 Mark) 
(a) Junk food, unclean house, contaminated water

(b) Balanced diet, Personal hygiene, Clean surrounding
(c) Polluted air, Uncovered food, Unbalanced diet
(d) Balanced diet, unclean surroundings, polluted water
Ans. b

(iii) Which part of the body is attacked by the bacteria causing tuberculosis if they enter through nose?   (1 Mark)
(a) Mouth
(b) Gut
(c) Lungs
(d) Kidney
Ans. c

(iv) How can we prevent the spread of air-borne diseases?  (1 Mark)
(a) By using clothes of infected person
(b) By drinking boiled water
(c) By drinking contaminated water
(d) By covering mouth while coughing or sneezing
Ans. d

(v) State True or False: Public cleanliness is important for individual health.   (1 Mark)
Ans: False

Q.20. Read the following and answer any 4 questions from 20 (i) to 20 (v).

(i) Which of the graphs indicate negative acceleration? Why?   (1 Mark)
(a) Graph I; since velocity decreases with time.
(b) Graph II; since velocity increases with time.
(c) Graph III; since velocity decreases with time.
(d) None of the graph shows negative acceleration.
Ans. a

(ii) What do you infer from the graph where velocity time graph is parallel to the time axis?  (1 Mark)
(a) Since velocity is constant the acceleration of the body is negative.
(b) Since velocity is constant the acceleration of the body is zero.
(c) Since velocity is varying the acceleration of the body is zero.
(d) Since velocity is zero  the acceleration of the body is zero.
Ans. b

(iii) Which of the graphs represent a body moving with initial velocity not equal to zero but with constant acceleration? Justify your answer.  (1 Mark)
(a) Graph II; since the velocity-time graph does not pass through the origin.
(b) Graph I; since the velocity-time graph does not pass through the origin.
(c) Graph III; since the velocity-time graph does not pass through the origin.
(d) None of the graphs represents a body moving with initial velocity not equal to zero but with constant acceleration.
Ans. c

(iv) Name the type of motion in which speed remains constant but the velocity of body changes.   (1 Mark)
(a) Uniform linear motion
(b) Uniform circular motion
(c) Non-Accelerated motion.
(d) Accelerated motion.
Ans. d

(v) Which two variables do the given graphs indicate?  (1 Mark)
(a) Speed and distance
(b) Velocity and time
(c) Speed and time
(d) Distance and time
Ans. b

Section – B

Q.21. An atom has 2 electrons in its outermost shell M. What is the atomic number of the element ? Also mention its name.  (2 Mark)
Ans. Atomic number of element = 12
   K      L     M
   2       8     2
Element is magnesium.

OR
Define valency. What conclusions can be drawn about the reactivity of an atom from its valency?  (2 Mark)
Ans. Valency: The combining capacity of an atom is known as its valency. Valency is the no. of electrons in outermost shell of an atom. The no. of electrons gained or lost or shared gives us the combining capacity of an atom and this decides whether an atom is reactive or not.

Q.22. State a difference between pure and impure substances.  (2 Mark)
Ans. Pure substances contain only one kind of particles or two or more particles in a fixed ratio, e.g. sugar, salt etc. While impure substance contains more than one kind of particles, e.g. milk, minerals etc.

Q.23. Write the formula of the compounds formed by the following ions:  (2 Mark)

(i) Cr³⁺ and SO₄^2– 
(ii) Pb²⁺ and NO₃^1–
Ans. (i)

(ii)

OR
Differentiate between :   (2 Mark)
(i) Atoms and molecules.
(ii) Molecular mass and formula unit mass.
Ans. (i) Atoms cannot exist independently whereas molecules can exist independently
(ii) Molecular mass is the sum of masses of the atoms in the molecule whereas formula unit mass is the sum of atomic masses of all the atoms in a formula unit of an ionic compound.

Q.24. Explain giving reasons :  (2 Mark)
(i) Balanced diet is necessary for maintaining healthy body.
(ii) Our surrounding areas should be free of stagnant water.
Ans. (i) Food is necessary for the growth and development of the body. Balanced diet provides raw materials and energy in appropriate amount in the form of protein, carbohydrates, fats, minerals etc. which, in turn, are essential for the proper growth and functioning of the healthy body. Lack of single nutrient may cause deficiency diseases.
(ii) Stagnant water provides a breeding ground for several disease-causing insects, especially mosquitoes. Mosquito acts as a vector for several diseases like malaria, dengue, etc. So, if we keep our surroundings clean and free from stagnant water, then these vectors will not find any place for breeding and automatically their population will decrease. This, in turn, will prevent the spread of insect-borne diseases.

Q.25. Name the separation techniques which you will apply for the separation of the following mixtures:
(i) Small pieces of metal in the engine oil of a car.
(ii) Wheat grains from husk.  (2 Mark)
Ans. (a) Filtration.
(b) Winnowing.

Q.26. Write the symptoms when following organs are targeted by microbes :
(i) Lungs
(ii) Liver  (2 Mark)
Ans. (i) Lungs : Cough, breathlessness
(ii) Liver : Digestive problems, metabolic problems, immune disorders.

Section - C

Q.27. Identify the simple permanent plant tissue with the following descriptions and also mention their location in the plant body :
(i) Cells have irregular wall thickenings.
(ii) Tissues with large intercellular spaces and cells having large air cavity.
(iii) Cells are long, narrow and dead in nature.  (3 Mark)
Ans. (i) Collenchyma,
(ii) Aerenchyma,
(iii) Sclerenchyma.
Location: Collenchyma: leaf stalks below the epidermis. Aerenchyma : stem and leaves of aquatic plants. Sclerenchyma : hard part of the plant (seed coat, mid rib etc.)

OR
Name the type of epithelial tissue that lines the following:
(i) Oesophagus
(ii) Respiratory tract
(iii) Kidney tubules
(iv) Inner lining of intestine
(v) Blood vessels
(vi) Ducts of salivary glands  (3 Mark)
Ans. (i) Squamous epithelium
(ii) Ciliated epithelium
(iii) Cuboidal epithelium
(iv) Columnar epithelium
(v) Squamous epithelium
(vi) Cuboidal epithelium

Q.28. (a) Under what conditions work is said to be done ?
(b) A porter lifts a luggage of 15 kg from the ground and puts it on his head 1.5 m above the ground. Calculate the work done by him on the luggage.  (3 Mark)
Ans. (a) (i) Force should be applied.
(ii) Body should move in the line of action of force.
(iii) Angle between force and displacement should not be 90°.
(b) Mass of luggage, m = 15 kg and
Displacement, s = 1.5 m
Work done, W = F × s = mg × s
= 15 × 10 × 1.5 = 225 J

Q.29. Identify the type of tissues in the following :  (3 Mark)
(i) Vascular bundle
(ii) Inner lining of the intestine
(iii) Lining of kidney tubule
(iv) Iris of the eye
(v) Muscles of the heart
(vi) Bronchi of lungs.
Ans. (i) Complex tissues
(ii) Columnar epithelium
(iii) Cuboidal epithelium
(iv) Involuntary muscular tissues
(v) Cardiac muscles
(vi) Ciliated cuboidal epithelium.

Q.30. Find the momentum of a body of mass 100 g having kinetic energy 500 J.  (3 Mark)
Ans. Using the formula for K.E. we get,
K.E. = 1 / 2 mv²
m = 100, g = 0.1 kg
K.E. = 500 J
v² = 2 x 500 / 0.1 = 10000
v = 100 m/s
Momentum = Mass × Velocity
= 0.1 × 100 = 10 kg m/s

Q.31. Which accident will be more damaging, collision between two trucks moving with a speed of 50 km/hr or collision between two cars moving with a speed of 50 km/hr ? Explain. (3 Mark)
Ans. Collision between trucks, because more is the mass, more is the inertia and therefore more is the momentum. Mass of the trucks is more than that of cars so collision of trucks will cause more damage.

Q.32. (i) State Newton’s third law of motion.
(ii) If someone jumps to the shore from a boat, the boat moves in the opposite direction. Explain.  (3 Mark)
Ans. (i) To every action, there is always an equal and opposite reaction.
(ii) The boat moves in the opposite direction due to the force exerted by the man to help him move in the forward direction which is the reaction force.

Q.33. (i) Name the type of energy possessed by a freely falling body of mass ‘m’ at the highest point ‘h’.
(ii) Define the energy.
(iii) A freely falling object eventually stops on reaching the ground. What happens to its kinetic energy?   (3 Mark)
Ans. (i) Potential energy.
(ii) Energy possessed by a body by virtue of its position.
(iii) It gets converted into heat and sound.

Section - D

Q.34. (i) What are the consequences of the following conditions?
(a) A cell having higher water concentration than the surrounding medium.
(b) A cell having lower water concentration than the surrounding medium.
(c) A cell having equal water concentration to its surrounding medium.
(ii) Name the materials of, which the cell membrane and cell wall are composed of.   (5 Mark)
Ans. (i) (a) When a cell possesses higher water concentration in the surrounding medium then exosmosis occurs in the cell due to the difference in concentration. As a result, the cell shrinks.
(b) When a cell has low water concentration than surrounding medium then endosmosis occurs that results in the swelling of the cell.
(c) A cell having equal water concentration to its surrounding medium will not show any change.
(ii) Cell wall is composed of cellulose and cell membrane is composed of lipids and proteins

OR
Draw a neat diagram of an animal cell and label any four parts of it.  (5 Mark)
Ans.

Q.35. (i) Calculate the number of electrons, protons and neutrons in an atom of an element with atomic number 20 and mass number 40. Write electronic configuration and draw the structure of the atom.
(ii) An atom has complete K and L shells. Is this an atom of a metal, non-metal or noble gas ? Justify.   (5 Mark)
Ans. (i) e = 20, p = 20, n = 40 – 20 = 20,
Electronic Configuration = 2, 8, 8, 2.
(ii) Atom has K shell = 2 e, L shell = 8 e
As K and L shells are completely filled.
∴ Total electrons = 2 + 8 = 10 e–
⇒ complete shell with 8 e–
Here the outer most shell completely filled as its capacity or 8 electrons.
∴ Noble gas.

Q.36. Hydrogen has three isotopes. State the composition of their nuclei and write their mass numbers. Also represent them in the form of symbols.  (5 Mark)
OR
Write postulates of Thomson’s model of an atom with diagram. What were the limitations of this model?  (5 Mark)
Ans. Isotopes of hydrogen are : Protium ₁H¹ (1 proton, 0 neutron), Mass no. 1 Deuterium ₁H² (1 proton, 1 neutron), Mass no. 2 Tritium ₁H³ (1 proton, 2 neutrons), Mass no. 3
OR
Postulates of Thomson’s model of an atom are :
(i) An atom is uniform sphere of positive charges (due to presence of protons) as well as negative charges (due to presence of electrons), which are embedded in it. This model is called, watermelon or plum pudding model’.
(ii) An atom, as a whole, is electrically because the negative and positive charges are equal in magnitude.
Limitations of Thomson’s model of atom were : 
(i) The model failed to explain how protons and electrons could be arranged in an atom so close to each other.
(ii) α-particles are charged particles having two units of positive charge and four units of mass, i.e., they are double charged helium ions (He²⁺)