CBSE Class 10 Science · Exam Practice

Science Practice Paper — Set 2

Science Practice Paper — Set 2. CBSE Class 10 Science, covering metals, carbon compounds, electricity, light, the human eye, control and coordination, reproduction and heredity, with a full answer key and worked solutions.

🎯 Full Marks: 50⏱️ Time: 1½ Hours📝 Questions: 30
SectionType of questionsQsMarks
AMultiple Choice Questions1010
BFill in the Blanks & True / False88
CShort Answer Questions816
DProblem Solving416
Total3050
Before you start
  • This paper samples across the CBSE Class 10 Science chapters on MuskMeadow: metals, carbon compounds, electricity, light, the human eye, control and coordination, reproduction and heredity.
  • Attempt the paper first, without looking at the answer key at the bottom of the page.
  • Show your working for Sections C and D — method marks are given even if the final answer is wrong.
  • This is a MuskMeadow practice paper. It is not an official CBSE paper and its mark scheme does not copy the board's exact pattern.
10 MARKS

Section A — Multiple Choice Questions

Choose the correct option. (1 mark each)

1. The metal that is liquid at room temperature is

A. sodiumB. mercuryC. ironD. zinc

2. The functional group present in alcohols is

A. –COOHB. –CHOC. –OHD. –Cl

3. A solution with pH 2 is

A. strongly acidicB. weakly acidicC. neutralD. basic

4. Pollination is the transfer of pollen from the anther to the

A. ovaryB. stigmaC. styleD. sepal

5. The defect of vision called myopia is corrected using a

A. convex lensB. concave lensC. plane mirrorD. bifocal lens

6. A device used to protect a circuit from overloading is a

A. switchB. fuseC. resistorD. battery

7. The number of carbon atoms in butane is

A. 2B. 3C. 4D. 5

8. The plant hormone that promotes cell division is

A. auxinB. gibberellinC. cytokininD. abscisic acid

9. The image formed by a plane mirror is always

A. real and invertedB. virtual and erectC. real and erectD. virtual and inverted

10. 1 kilowatt-hour is equal to

A. 3.6 × 10⁶ JB. 3.6 × 10³ JC. 1000 JD. 60 J
8 MARKS

Section B — Fill in the Blanks & True / False

Fill in each blank, or write True / False. (1 mark each)

11. The enzyme present in saliva that digests starch is ______.

12. Ionic compounds generally have high melting points. (   )

13. The lens formula is 1/v − 1/u = ______.

14. Vegetative propagation produces offspring that are genetically identical to the parent. (   )

15. The SI unit of electric charge is the ______.

16. Fertilisation in human females normally takes place in the ______.

17. Acids turn blue litmus red. (   )

18. Coating iron with a layer of zinc to prevent rusting is called ______.

16 MARKS

Section C — Short Answer Questions

Show your working. (2 marks each)

19. Balance: Al + O₂ → Al₂O₃.

20. A bulb is rated 100 W, 220 V. Find the resistance of its filament.

21. An object 5 cm tall forms an image with magnification −2. Find the image height and describe the image.

22. Name two methods of preventing the rusting of iron.

23. Write the molecular formulae of ethane and ethanol.

24. What is a reflex action? Give one example.

25. A current of 2 A flows through a 5 Ω resistor for 10 s. Find the heat produced.

26. How many chromosomes does a human gamete (sperm or egg) contain?

16 MARKS

Section D — Problem Solving

Show all steps. (4 marks each)

27. Resistors of 2 Ω, 3 Ω and 6 Ω are connected in parallel across a 6 V battery. Find (a) the equivalent resistance, (b) the current in each resistor and (c) the total current.

28. A concave mirror has focal length 15 cm. Find the image distance and magnification when an object is placed (a) 30 cm and (b) 10 cm in front of it, and describe each image.

29. (a) Write the molecular formulae of the first three alkanes. (b) Write the balanced equation for the complete combustion of methane. (c) Using C = 12, H = 1, O = 16, find the mass of carbon dioxide produced from 16 g of methane.

30. Name the part of the brain that controls (a) thinking and memory, (b) balance and posture, (c) involuntary actions such as the heartbeat. (d) Which gland releases growth hormone?

CBSE Class 10 Science · Science Practice Paper — Set 2 · Answer Key

Answers & Worked Solutions

Check your paper, then read the solutions for the questions you missed.

Section A — Multiple Choice Questions (10 marks)
Q1. B. mercury

Mercury is the only common metal that is liquid at room temperature.

Q2. C. –OH

Alcohols contain the hydroxyl (–OH) group.

Q3. A. strongly acidic

pH well below 7 means a strong acid (like lemon juice).

Q4. B. stigma

Pollen lands on the stigma, the receptive tip of the carpel.

Q5. B. concave lens

In myopia the eye focuses in front of the retina; a concave lens diverges the rays.

Q6. B. fuse

A fuse wire melts when current exceeds a safe limit.

Q7. C. 4

But- means four: C₄H₁₀.

Q8. C. cytokinin

Cytokinins stimulate cell division (found in fruits and seeds).

Q9. B. virtual and erect

It is formed behind the mirror and cannot be taken on a screen.

Q10. A. 3.6 × 10⁶ J

1 kWh = 1000 W × 3600 s = 3.6 × 10⁶ J.

Section B — Fill in the Blanks & True / False (8 marks)
Q11. amylase

Salivary amylase begins the digestion of starch in the mouth.

Q12. True

Strong electrostatic forces hold the ions together.

Q13. 1/f

u, v and f are measured with the sign convention.

Q14. True

No gametes are involved.

Q15. coulomb

1 C = 1 A × 1 s.

Q16. oviduct (fallopian tube)

The ovum and sperm meet there.

Q17. True

This is the standard litmus test for acids.

Q18. galvanisation

Zinc protects the iron even if the layer is scratched.

Section C — Short Answer Questions (16 marks)
Q19. 4Al + 3O₂ → 2Al₂O₃
  1. Balance oxygen first: 3 O₂ and 2 Al₂O₃ give 6 O atoms.
  2. Then 4 Al on the left: 4Al + 3O₂ → 2Al₂O₃.
Q20. 484 Ω
  1. P = V²/R, so R = V²/P.
  2. R = 220²/100 = 48400/100 = 484 Ω.
Q21. −10 cm: real and inverted
  1. Image height = m × object height = −2 × 5 = −10 cm.
  2. Negative sign: the image is inverted (and real); magnitude 2 means enlarged.
Q22. Painting; galvanisation
  1. Painting or oiling keeps air and moisture away.
  2. Galvanisation (zinc coating), alloying (stainless steel) or tin-plating also work.
Q23. C₂H₆; C₂H₅OH
  1. Ethane is a two-carbon alkane: C₂H₆.
  2. Ethanol is ethane with one H replaced by –OH: C₂H₅OH.
Q24. Quick, involuntary response to a stimulus
  1. A reflex action is a sudden, automatic response that does not wait for the brain’s decision.
  2. Example: pulling the hand away from a hot object.
Q25. 200 J
  1. H = I²Rt.
  2. H = 2² × 5 × 10 = 200 J.
Q26. 23
  1. A human body cell has 46 chromosomes (23 pairs).
  2. Gametes are formed by meiosis and have half: 23.
Section D — Problem Solving (16 marks)
Q27. (a) 1 Ω (b) 3 A, 2 A, 1 A (c) 6 A
  1. (a) 1/R = 1/2 + 1/3 + 1/6 = 6/6 = 1, so R = 1 Ω.
  2. (b) Each has 6 V across it: I = 6/2 = 3 A, 6/3 = 2 A, 6/6 = 1 A.
  3. (c) Total current = 3 + 2 + 1 = 6 A (also 6/1 = 6 A ✓).
Q28. (a) v = −30 cm, m = −1 (b) v = +30 cm, m = +3
  1. Take f = −15 cm.
  2. (a) u = −30: 1/v = 1/f − 1/u = −1/15 + 1/30 = −1/30, so v = −30 cm; m = −v/u = −1. Real, inverted, same size (object at the centre of curvature).
  3. (b) u = −10: 1/v = −1/15 + 1/10 = 1/30, so v = +30 cm; m = −v/u = +3. Virtual, erect and enlarged.
Q29. (a) CH₄, C₂H₆, C₃H₈ (b) CH₄ + 2O₂ → CO₂ + 2H₂O (c) 44 g
  1. (a) Methane CH₄, ethane C₂H₆, propane C₃H₈.
  2. (b) CH₄ + 2O₂ → CO₂ + 2H₂O.
  3. (c) 16 g CH₄ (1 mole, 12 + 4 = 16) gives 44 g CO₂ (12 + 32 = 44), since one CH₄ gives one CO₂.
Q30. (a) cerebrum (b) cerebellum (c) medulla (d) pituitary
  1. (a) The cerebrum (fore-brain) handles thinking, memory and voluntary action.
  2. (b) The cerebellum maintains balance and posture.
  3. (c) The medulla oblongata controls involuntary actions such as heartbeat and breathing.
  4. (d) The pituitary gland secretes growth hormone.
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