Class 12 Science Olympiad Previous Year Paper – Quick Guide

Updated for 2026–27: This is an archived SCO Olympiad Class 12 Science previous-year practice paper. The legacy URL is preserved because it already has Google search history, but the visible content is now correctly aligned with School Connect Olympiad.

Class 12 does not use one single combined NCERT Science textbook. Students normally study separate Physics, Chemistry and Biology books, so this paper is best used as mixed higher-secondary science practice rather than as a replacement for the current textbook sequence.

Use the paper to test concepts, identify weak areas and practise switching between Biology, Chemistry and Physics questions. For current SCO Olympiad information and preparation resources, visit SCO International Science Olympiad.

SCO Olympiad Class 12 Science Previous Year Paper PDF – Free Download

How to Use This Archived Class 12 Paper

• Attempt the questions before looking at the answer key.
• Mark each error as Physics, Chemistry or Biology so you can identify the subject area that needs revision.
• For numerical questions, write the formula and units before substituting values.
• For Chemistry and Biology questions, explain why the other options are wrong instead of memorising only the correct letter.
• Re-attempt incorrect questions after revising the concept.

Important: This is an archived practice paper. Current SCO exam instructions, response-sheet rules, permitted materials, timings and marking rules may change. Always follow the instructions on the current paper or admit card rather than relying on old OMR directions.

1. In the terminology used in this archived paper, GEAC stands for: 

1. Genome Engineering Action Committee 
2. Ground Environment Action Committee 
3. Genetic Engineering Approval Committee 
4. Genetic and Environment Approval Committee

2. The C-peptide of human insulin is: 

1. A part of mature insulin molecule 
2. Responsible for formation of disulphide bridges 
3. Removed during maturation of pro-insulin to insulin 
4. Responsible for its biological activity.

3. Approximately what percentage of photosynthetically active radiation (PAR) is captured by plants for photosynthesis in the standard textbook context? 

1. Less than 1% 
2. 2-10% 
3. 30% 
4. 50%

4. Which of the following reagents would not be a good choice for reducing an aryl nitro compound to an amine?

1. H2(excess)/Pt
2. LiAlH₄ in ether
3. Fe and HCl
4. Sn and HCl

5. Which of the following options are correct for [Fe(CN)₆]^3– complex?

1. d²sp³ hybridisation
2. sp³d² hybridisation
3. paramagnetic
4. diamagnetic

6. The correct order of acidity of the following chlorine oxyacids is:

1. HClO₄ < HClO₃ < HClO₂ < HClO
2. HClO < HClO₂ < HClO₃ < HClO₄
3. HClO < HClO₄ < HClO₃ < HClO₂
4. HClO₄ < HClO₂ < HClO₃ < HClO

7. Choose the correct answer out of the following choices:

Assertion – Haloalkanes are slightly soluble in water.

Reason – Intermolecular attractions between haloalkanes and solvent molecules have much more strength than intermolecular attractions between haloalkane molecules.

1. Both assertion and reason are correct statements, and reason is the correct explanation of the assertion.
2. Both assertion and reason are correct statements, but reason is not the correct explanation of the assertion.
3. The assertion is correct, but the reason is an incorrect statement.
4. An assertion is incorrect, but a reason is a correct statement.

8. A 220 V A.C. supply is connected between points A and B in below figure. What will be the potential difference V across the capacitor?

1. 220V
2. 110V
3. 0V
4. 220√2 V

9. The radius of curvature of the curved surface of a plano-convex lens is 20 cm. If the refractive index of the material of the lens be 1.5, it will:

1. act as a convex lens only for the objects that lie on its curved side.
2. act as a concave lens for the objects that lie on its curved side.
3. act as a convex lens irrespective of the side on which the object lies.
4. act as a concave lens irrespective of side on which the object lies.

10. The electrical conductivity of the metal decreases with temperature, because:

1. The energy of the electrons increases with temperature.
2. A metal expands on heating.
3. The atoms of the metal vibrate more at higher temperatures.
4. Metals have low specific heat.

Answer Keys:

Ques. 1	(c) — archived terminology	Ques. 6	(b)
Ques. 2	(c)	Ques. 7	(c)
Ques. 3	(b)	Ques. 8	(d)
Ques. 4	(b)	Ques. 9	(c)
Ques. 5	(a) and (c)	Ques. 10	(c)

Selected Answer Explanations

• Q1 – (c), archived terminology: the paper uses the older name “Genetic Engineering Approval Committee.” The official body is now called the Genetic Engineering Appraisal Committee; the name was changed in 2010.
• Q2 – (c): C-peptide is removed when proinsulin is processed into mature insulin.
• Q3 – (b): in the standard textbook context, plants capture roughly 2–10% of photosynthetically active radiation (PAR) for photosynthesis.
• Q4 – (b): for this NCERT Exemplar-style question, LiAlH₄ in ether is not the preferred reagent for converting an aryl nitro compound cleanly to an amine.
• Q5 – (a) and (c): [Fe(CN)₆]³⁻ is a low-spin inner-orbital complex with d²sp³ hybridisation and one unpaired electron, so it is paramagnetic.
• Q7 – (c): haloalkanes are only slightly soluble in water, but the stated reason is incorrect because their interactions with water are not strong enough to compensate for the disruption of water–water hydrogen bonding.
• Q8 – (d): a 220 V AC supply is an RMS value; the capacitor charges to the peak value, 220√2 V, in the ideal diode-capacitor arrangement shown.
• Q9 – (c): a plano-convex lens in air remains converging regardless of which side faces the object.
• Q10 – (c): as temperature rises, metal-lattice vibrations increase, causing more electron scattering and therefore lower electrical conductivity. The old key incorrectly listed option (a).

Class 12 Science Olympiad FAQs

Is this PDF from SCO Olympiad?

Yes. The PDF is an archived School Connect Olympiad Class 12 Science practice paper. The older URL has been retained to preserve search history.

Can I download the Class 12 Science Olympiad paper free?

Yes. Use the PDF download button above to save the archived paper for practice.

Does this paper exactly match the current Class 12 syllabus?

Not necessarily. It is a previous-year mixed-science paper. Current Class 12 learning is organised through separate Physics, Chemistry and Biology textbooks, and competition patterns can also change.

Where can I continue Science Olympiad preparation?

Continue with SCO International Science Olympiad resources and use previous papers as diagnostic practice rather than memorising answer letters.

Related Science Olympiad Practice

• Class 11 Science Olympiad Previous Year Paper
• Class 10 Science Olympiad Previous Year Paper
• Class-wise Olympiad Previous Papers
• Science Olympiad Learning Resources