CBSE

SAMPLE PAPER 3
Class 10 - Science
Time Allowed: 3 hours Maximum Marks: 80

General Instructions:

1. This question paper consists of 39 questions in 5 sections.

2. All questions are compulsory. However, an internal choice is provided in some questions. A student is expected to

attempt only one of these questions.

3. Section A consists of 20 objective-type questions carrying 1 mark each.

4. Section B consists of 6 Very Short questions carrying 02 marks each. Answers to these questions should be in the

range of 30 to 50 words.

5. Section C consists of 7 Short Answer type questions carrying 03 marks each. Answers to these questions should
be in the range of 50 to 80 words.

6. Section D consists of 3 Long Answer type questions carrying 05 marks each. Answers to these questions should

be in the range of 80 to 120 words.

7. Section E consists of 3 source-based/case-based units of assessment of 04 marks each with sub-parts.

Section A
1. The copper articles turn green when kept for long due to [1]

a) Corrosion b) Rusting

c) Precipitation d) Rancidity
2. Select endothermic reaction from the following: [1]

a) Burning of a candle. b) Process of respiration.

c) Decomposition of vegetable matter into d) Decomposition of calcium carbonate to

compost. form quick lime and carbon dioxide.
3. HNO3 is a strong acid because: [1]

a) It does dissociate into ions at all b) It doesn’t dissociate into ions at all

c) It dissociates partially in aqueous solution d) It dissociates completely in aqueous

solution
4. A solution reacts with crushed egg shells to give a gas that turns lime water milky. The solution contains [1]

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 a) LiCl b) KCl

c) HCl d) NaCl
5. A metal is heated with dil H2SO4. The gas evolved is collected by the method shown in the figure. Answer the [1]
following questions based on it:

Name the method used for the collection of gas.

a) Upward displacement method b) Downward replacement method

c) Downward displacement method d) Upward replacement method

6. A basic lining is given to a furnace by using: [1]

a) Silica b) Haematite

c) Calcined dolomite d) Copper sulphate

7. In which of the following compounds, -OH is the functional group? [1]

a) Butanoic acid b) Butanol

c) Butanal d) Butanone
8. In which kind of respiration more energy is released? [1]

a) All of these b) Photorespiration

c) Aerobic respiration d) Anaerobic respiration

9. Which of the following is secreted by the posterior lobe of Pituitary? [1]
A. Growth hormone
B. Thyroid-stimulating hormone
C. Oxytocin
D. Vasopressin

a) B and C b) A and C

c) C and D d) All of these

10. Which among the following is not the function of testes at puberty? [1]
i. formation of germ cells
ii. secretion of testosterone
iii. development of placenta
iv. secretion of estrogen

a) (i) and (ii) b) (iii) and (iv)

c) (ii) and (iii) d) (i) and (iv)

11. A trait in an organism is influenced by [1]

a) Both maternal & Paternal DNA b) Paternal DNA only

c) Neither maternal nor paternal DNA. d) Maternal DNA only

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12. As compared to daytime, the amount of carbon dioxide released by the plants during night is more because: [1]

a) It is stored in the leaves of plants during b) Plants do not respire during daytime.
daytime.

c) It is not produced during daytime. d) Major amount of carbon dioxide produced

is used up for photosynthesis during
daytime.
13. Which of the following can make a parallel beam of light when light from a point source is incident on it? [1]

a) Convex mirror as well as concave lens b) Two plane mirrors placed at 90° to each
other

c) Concave mirror as well as convex lens d) Concave mirror as well as concave lens
14. The lens system of human eye forms an image on a light sensitive screen, which is called as: [1]

a) Optic nerves b) Cornea

c) Ciliary muscles d) Retina

15. Disposable plastic plates should not be used because: [1]

a) They are made of non-biodegradable b) They are made of biodegradable materials.

material.

c) They are made of toxic materials. d) They are made of materials with light
weight.
16. Habitat is the special environment of an organism in which: [1]
A. It lives
B. It grows
C. It breeds
D. It gets food

a) All of these b) A and B

c) A and C d) A, B and C
17. Assertion (A): Brown fumes are produced when lead nitrate is heated. [1]
Reason (R): Nitrogen dioxide gas is produced as a byproduct due to the decomposition of lead nitrate.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

18. Assertion (A): Pores are unicellular bodies. [1]
Reason (R): The parent body simply breaks up into smaller pieces on maturation.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

19. Assertion (A): A proton moves horizontally towards a vertical long conductor having an upward electric [1]
current. It will deflect vertically downward.

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 Reason (R): Seeing the proton and the conductor from the side of the proton, the magnetic field at the site of the
proton will be towards the right. Hence the force F ⃗ = qν ⃗ × B
⃗
will deflect the proton vertically downward.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

20. Assertion (A): Ozone is both beneficial and damaging. [1]
Reason (R): Stop the release of chlorofluorocarbons to protect the ozone.

a) Both A and R are true and R is the correct b) Both A and R are true but R is not the
explanation of A. correct explanation of A.

c) A is true but R is false. d) A is false but R is true.

Section B
21. What is 'baking powder'? How does it make the cake soft and spongy? [2]
22. Explain how, offspring and parents of organisms reproducing sexually have the same number of chromosomes. [2]
23. How are water and minerals transported in plants? [2]
OR
With the help of diagram, show pulmonary circulation in man.
24. What is the cause of refraction of light when it passes from one medium to another? [2]
25. Draw a diagram to show the pattern of magnetic field lines on a horizontal sheet of paper due to a straight [2]
conductor passing through its centre and carrying current vertically upwards. Mark on it (i) the direction of
current in the conductor and (ii) the corresponding magnetic field lines. State right hand thumb rule and check
whether the directions marked by you are in accordance with this rule or not.
OR
In the circuit given below, the resistors R1, R2 and R3 have the values 10 Ω , 20 Ω and 30 Ω respectively, which have

been connected to a battery of 12 V. Calculate

a. the current through each resistor,
b. the total circuit resistance, and
c. the total current in the circuit.

26. We water the soil but it reaches the topmost leaves of the plants. Explain in brief the process involved. [2]
Section C
27. A group of a students looked at different metals and metal sulphate solutions given is a tabular form. From the [3]
data, answer the following:

Metal Metal sulphate solution Colour

Chromium Chromium sulphate Green

Cobalt Cobalt sulphate Pink

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 Copper Copper sulphate Blue

Magnesium Magnesium sulphate Colourless

i. Which metal reacts with all other sulphate solutions?

ii. Which metal did not react with any other metal sulphate solution?
iii. Arrange the metals in decreasing order of reactivity.
28. State three reasons for the following facts: [3]
i. Sulphur is a non-metal.
ii. Magnesium is a metal.
One of the reasons must be supported with a chemical equation.
OR
Give the characteristic tests for H2.

29. What would be the consequences of a deficiency of haemoglobin in our bodies? [3]
30. A child questioned his teacher that why do organisms resemble their parents more as compared to grandparents. [3]
In which way will the teacher explain to the child?
31. A pencil when dipped in water in a glass tumbler appears to be bent at the interface of air and water. Will the [3]
pencil to be bent to the same extent, if instead of water we use liquids like, kerosene or turpentine? Support your
answer with reasons.
32. A battery E is connected to three identical lamps P, Q and R as shown in figure: [3]

Initially the switch S is kept open and the lamp P and Q are observed to glow with same brightness. Then switch
S is closed. How will the brightness of the glow of bulbs P and Q will change? Justify your answer.
33. For a heater, rated 4 kW and 220 V, calculate the following: [3]
a. The current
b. Energy consumed in 2 hours
c. If 1 kWh is priced at ₹4.50, then the cost of energy consumed
Section D
34. i. Draw the structure of the following compounds: [5]

a. Butanoic acid
b. Chloropentane
ii. How are structure (i) and structure (ii) given below related to one another? Give reason to justify your
answer.

Draw one more possible structure for above case.

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 iii. Differentiate between saturated and unsaturated carbon compounds on the basis of their general formula.
OR
a. Carry out the following conversions giving complete conditions for the reaction to take place in each case:
i. Ethanoic acid from Ethanol
ii. Ethane from Ethene
iii. Ester from Ethanoic acid and ethanol
Also state the names given to all the above conversions.
b. Detergents are preferred over soaps. Why? (Give one reason)

35. a. What is puberty? Write any two changes that occur in boys during early teenage years. [5]
b. List two functions performed by testis in human males.
Mention one role each of (i) Vas deferens, (ii) Seminal Vesicle (iii) Urethra and (iv) Scrotum in human male
reproductive system.
OR
i. Leaves of chhui-mui plant begin to fold up and droop in response to a stimulus. Name the stimulus and write the
cause for such a rapid movement. Is there any growth involved in the movement?
ii. Define geotropism in plants. What is meant by positive and negative geotropism? Give one example of each type.

36. i. Draw a ray diagram to show the path of the reflected ray in each of the following cases: [5]
A ray of light incident on a convex mirror
1. parallel to its principal axis, and
2. is directed towards its principal focus
ii. A 1.5 cm tall candle flame is placed perpendicular to the principal axis of a concave mirror of focal length 12
cm. If the distance of the flame from the pole of the mirror is 18 cm, use mirror formula to determine the
position and size of the image formed.
OR
i. State laws of refraction of light.
ii. Draw a ray diagram to show refraction of a ray of light through a rectangular glass slab. How is the emergent ray
related to incident ray? Mark lateral displacement in the diagram.
Section E
37. Read the following: [4]
H H H H H H

| | | | | |

H − C ≡ C − C − H, H − C − Br, H − C − C − OH, H − C − C − H, H − C ≡ C − H ,
| | | | | |

H H H H H H
(P) (Q) (T)
(R) (S)

i. Which of the compounds P, Q, R, S, T, U belong to same homologous series? (1)

ii. Write the name of compound R. Also write the functional group present in it. (1)
iii. What is the IUPAC name of compound T and U (2)
OR
What are unsaturated hydrocarbons? Which of the compounds P, Q, R, S, T , U are example of unsaturated
hydrocarbons? (2)
38. Read the following text carefully and answer the questions that follow: [4]
Refer to the schematic representation of albinism which is an inherited condition caused by a recessive allele (a).

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 ‘A’ is the dominant allele for the normal condition. The inheritance of certain genetic traits for two or more
generations is represented in a pedigree or family tree. Study the given pedigree chart and answer the following
questions.

i. What could be the genotypes of X and Y? (1)

ii. What could be the genotype of generation - 1 male and female? (1)
iii. If X married an albino female, then what is the probability that their children would be albino? (2)
OR
If Y married a normal homozygous male, then what is the probability that their children would be albino? (2)
39. Read the following text carefully and answer the questions that follow: [4]
Consider the following electrical circuit diagram in which nine identical resistors of 3 Ω each are connected as
shown. If the reading of the ammeter A1 is 1 ampere, answer the following questions:

i. What is the relationship between the readings of A1 and A3? Give reasons for your answer. (1)

ii. What is the relationship between the readings of A2 and A3? (1)
iii. Determine the reading of the voltmeter V1. (2)
OR
Find the total resistance of the circuit. (2)

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