Updated for 2026–27: This page contains an archived SCO Olympiad Class 10 Science previous-year practice paper with an embedded PDF, 10 practice questions and an answer key. The existing URL is being preserved because it already has Google search history, while the visible page now correctly identifies the resource as SCO Olympiad.

Use this paper as a diagnostic exercise: attempt it first without checking the key, mark every guessed answer, and then revise the science concept behind each mistake. For Class 10, this is more useful than memorising old option letters because many questions require multi-step reasoning in chemistry and physics.

Current curriculum note: NCERT’s current Class X Science textbook continues to cover core areas such as chemical reactions, acids and bases, carbon compounds, light and magnetic effects. The paper therefore remains useful for concept practice, but students should follow their current school textbook and teacher guidance for the latest sequence and assessment pattern.

SCO Olympiad Class 10 Science Previous Year Paper PDF – Free Download

The embedded PDF is an SCO Olympiad Class 10 Science practice resource. Students who want to continue with current preparation can explore SCO International Science Olympiad resources after reviewing their mistakes.

How to Use This Class 10 Science Olympiad Paper

• Attempt the paper once without checking the answer key.
• Use a timer and mark questions that took unusually long.
• Separate mistakes into concept errors, calculation errors and careless reading.
• Revise the weak topic from the current textbook before retrying the question.
• For numerical or reaction-based questions, write the reasoning or working rather than guessing from the options.

Important: this is an archived practice paper. Exam-day instructions, section names, response-sheet rules and scoring can change, so always follow the current SCO Olympiad paper, admit card and official guidance.

A student in class X was doing an experiment in a chemistry lab, he mixed lead nitrate and potassium iodide. After completing the experiment, he observed a lot of changes in the test tube.

1.  He saw a yellow precipitate of:

1. Potassium Nitrate.
2. Lead Iodide.
3. Potassium Iodide.
4. Potassium Oxide.

2. The chemical reaction involved in this reaction is:

1. Pb(NO₃)₃ + KI →PbI₂ + 2KNO₃
2. Pb(NO₃)₂ + 2KI →PbI₂ + 2KNO₃
3. Pb(NO₃)₂ + 3KI →PbI₂ + 3KNO₃
4. Pb(NO₃)₃ + 3KI →PbI₂ + 3KNO₃

3. Nitric acid is an oxidising acid and generally does not release hydrogen gas with metals. However, very dilute nitric acid can evolve hydrogen with some metals. Which option below is one such metal?

1. Aluminium
2. Copper
3. Magnesium
4. Sodium

4. The chemical name and formula of plaster of Paris is written as:

1. Calcium Sulphate decahydrate CaSO₄.10H₂O
2. Calcium Sulphate hemihydrate CaSO₄.1/2H₂O
3. Calcium Sulphate dehydrate CaSO₄
4. Calcium Sulphate dihydrate CaSO₄.2H₂O

5. Which of the following statement is correct:

1. Copper sulphate contains two molecules of water of crystallisation
2. Copper sulphate contains three molecules of water of crystallisation
3. Copper sulphate contains four molecules of water of crystallisation
4. Copper sulphate contains five molecules of water of crystallization

6. Match the items given in column A with the column B –

Column A	Column B
1. Ferrous Sulphate + heat	i) Exothermic reaction
2. Barium chloride + Sodium sulphate	ii) displacement
3. Respiration	iii) Precipitation reaction
4. Copper sulphate solution + Zinc	iv) Decomposition reaction

1. 1-(iii), 2-(ii), 3-(iv), 4-(i)
2. 1-(iv), 2-(iii), 3-(i), 4-(ii)
3. 1-(i), 2-(ii), 3-(iv), 4-(iii)
4. 1-(ii), 2-(iv), 3-(i), 4-(iii)

7. Which of the following statements about hydrocarbons are correct?

1. Saturated hydrocarbons generally undergo addition reactions.
2. Unsaturated hydrocarbons can undergo hydrogenation.
3. Butane is an unsaturated hydrocarbon.
4. Unsaturated hydrocarbons are generally more reactive than saturated hydrocarbons.

1. I and II
2. II, III and IV
3. II and IV
4. I and IV

Answer the Q- 8 and 9 on the basis of the diagram given below:

8.What type of energy conversion is observed in a solenoid?

1. Kinetic to Electrical
2.  Electrical to Kinetic
3. Electrical to Magnetic
4.  Magnetic to Electrical

9. The strength of magnetic field produced by a solenoid can be increased by:

1. Increasing number of cells
2. Increasing the number of turns of wire
3. Interchanging the polarities of the battery
4. Both (a) and (b)

10. A lens forms an image with magnification −1. If the object is 30 cm from the lens, what is the focal length of the lens?

1. 30.5cm                  
2. 30cm           
3. 15cm           
4. 7.5cm

Check your responses only after attempting all 10 questions.

Answer Key

Ques. 1	(b)	Ques. 6	(b)
Ques. 2	(b)	Ques. 7	(c)
Ques. 3	(c)	Ques. 8	(c)
Ques. 4	(b)	Ques. 9	(d)
Ques. 5	(d)	Ques. 10	(c)

Quick Explanations for Selected Answers

• Q1: Lead nitrate reacts with potassium iodide to form a bright yellow precipitate of lead iodide, PbI₂.
• Q2: The balanced reaction is Pb(NO₃)₂ + 2KI → PbI₂ + 2KNO₃.
• Q3: Very dilute nitric acid can evolve hydrogen with magnesium; nitric acid usually behaves as an oxidising acid with metals.
• Q5: Crystalline copper sulphate is CuSO₄·5H₂O, so it contains five molecules of water of crystallisation.
• Q7: Unsaturated hydrocarbons can undergo hydrogenation and are generally more reactive than saturated hydrocarbons, so statements II and IV are correct.
• Q10: Magnification −1 means a real inverted image of the same size, produced when the object is at 2F. If the object distance is 30 cm, 2F = 30 cm and the focal length is 15 cm.

Class 10 Science Olympiad FAQs

Is this PDF from SCO Olympiad?

Yes. The downloadable PDF and the practice questions on this page are SCO Olympiad Class 10 Science material retained as a previous-year practice resource.

Can I download the Class 10 Science Olympiad paper for free?

Yes. The embedded PDF can be opened or downloaded free for revision, timed practice and concept review.

Does this archived paper exactly match the current Class 10 syllabus?

Not necessarily. It remains useful for concept application and Olympiad-style reasoning, but students should follow the current NCERT or school textbook for the latest chapter sequence and assessment requirements.

Where can I continue with SCO Class 10 Science Olympiad preparation?

Continue with SCO International Science Olympiad resources and use the mistakes from this paper to decide which topics need further practice.

Related Science Olympiad Practice Resources

• Class 9 Science Olympiad previous-year paper
• Class 11 Science Olympiad previous-year paper
• Class-wise Olympiad previous papers