Class 9 Science Olympiad: Practice Questions & Answers

Updated for 2026: this page offers 15 original Class 9 Science Olympiad questions with worked answers covering Biology, Chemistry and Physics. Use them to practise key concepts and identify topics to revise.

For current preparation, Class 9 students should use the dedicated SCO Biology, Chemistry and Physics pathways, each of which now provides its own 2026 syllabus, sample paper, answer key and previous-year paper.

Current SCO Class 9 Science Resources for 2026

Class 9 Olympiad hub — choose the current subject pathway.
Class 9 Biology Olympiad — syllabus, sample paper, answer key and previous-year paper.
Class 9 Chemistry Olympiad — current chemistry practice resources.
Class 9 Physics Olympiad — current physics practice resources.

Recommended sequence: try the questions below → check the worked explanations → identify your weakest science topic → revise the relevant chapter → use your chosen organiser’s current sample paper.

Schedule note: use the live SCO exam calendar for active dates because individual subject pages can retain an older “next exam” label after a slot has passed.

How to Use These Class 9 Science Questions

Attempt the questions without checking the answer key.
Mark every guessed answer, even when it turns out to be correct.
Classify each error as Biology, Chemistry, Physics, reasoning or reading/diagram interpretation.
Review the explanation, then solve one fresh question on the same concept.
Use the instructions from your chosen Olympiad organiser for any timed examination; the questions on this page are designed for learning.

15 Class 9 Science Olympiad Practice Questions with Answers

Practise Biology, Chemistry and Physics with original multiple-choice questions. Each answer includes a worked explanation, so you can study directly on the page without an image or a separate answer sheet.

Physics

Question 1. A 5 kg box is lifted vertically by 4 m. What is the gain in gravitational potential energy if g = 10 m/s²?
A. 20 J | B. 50 J | C. 200 J | D. 500 J
Answer: C. 200 J. Potential energy = mass × gravity × height = 5 × 10 × 4 = 200 J.
Question 2. Two equal forces of 12 N act on an object in exactly opposite directions. What is the net force?
A. 0 N | B. 12 N | C. 24 N | D. 144 N
Answer: A. 0 N. Equal opposite forces cancel; the net force is zero.
Question 3. A cyclist travels 150 m in 30 seconds. What is the average speed?
A. 3 m/s | B. 5 m/s | C. 30 m/s | D. 180 m/s
Answer: B. 5 m/s. Speed = distance ÷ time = 150 ÷ 30 = 5 metres per second.
Question 4. Which is the correct SI unit of force?
A. Joule | B. Pascal | C. Newton | D. Watt
Answer: C. Newton. Force is measured in newtons, named after Isaac Newton.
Question 5. What energy transformation mainly occurs in a torch powered by a battery?
A. Light into chemical | B. Chemical into electrical and light | C. Sound into heat | D. Heat into chemical
Answer: B. Chemical into electrical and light. Battery chemical energy is converted to electrical energy, then to light and some heat.

Chemistry

Question 6. Which process removes a liquid from a salt solution by heating, leaving solid salt behind?
A. Condensation | B. Evaporation | C. Filtration of dissolved salt | D. Magnetic separation
Answer: B. Evaporation. As water evaporates, dissolved salt remains.
Question 7. Which is a pure substance made of only one type of atom?
A. Air | B. Soil | C. Copper | D. Seawater
Answer: C. Copper. Copper is an element containing copper atoms. The others are mixtures.
Question 8. How many atoms are present in one molecule of water, H₂O?
A. 2 | B. 3 | C. 4 | D. 1
Answer: B. 3. Water contains two hydrogen atoms and one oxygen atom: three in all.
Question 9. A liquid changes into gas at its surface below its boiling point. What is the process?
A. Freezing | B. Evaporation | C. Melting | D. Condensation
Answer: B. Evaporation. Evaporation can occur at the surface of a liquid at temperatures below boiling.
Question 10. Which mixture can be separated using a magnet?
A. Salt dissolved in water | B. Sugar dissolved in water | C. Iron filings and sand | D. Vinegar and water
Answer: C. Iron filings and sand. Iron filings are attracted to a magnet while sand is not.

Biology

Question 11. Which plant tissue carries water from roots to other parts of a plant?
A. Phloem | B. Xylem | C. Epidermis | D. Parenchyma
Answer: B. Xylem. Xylem mainly transports water and dissolved minerals upward.
Question 12. Which cellular structure is the main site of photosynthesis in green plants?
A. Nucleus | B. Chloroplast | C. Vacuole | D. Ribosome
Answer: B. Chloroplast. Chloroplasts contain chlorophyll and carry out photosynthesis.
Question 13. Which tissue joins a muscle to a bone?
A. Ligament | B. Tendon | C. Cartilage | D. Xylem
Answer: B. Tendon. Tendons connect muscle to bone; ligaments connect bone to bone.
Question 14. Which cell component controls what enters and leaves a cell?
A. Cell membrane | B. Cell wall only | C. Cytoplasm only | D. Nucleolus
Answer: A. Cell membrane. The cell membrane selectively regulates the movement of materials in and out.
Question 15. Which process releases energy from food inside living cells?
A. Photosynthesis | B. Transpiration | C. Cellular respiration | D. Diffusion
Answer: C. Cellular respiration. Cells release usable energy from food molecules through respiration.

Fresh Class 9 Science Mini Challenge

Which change will usually increase evaporation from an open container?
A. Lower temperature B. Smaller exposed area C. Higher temperature D. Higher humidity
A 5 kg object is raised vertically by 4 m. Taking g = 10 m/s², what is the gain in gravitational potential energy?
A. 20 J B. 50 J C. 200 J D. 500 J
Which plant tissue mainly provides mechanical strength because of thick lignified walls?
A. Parenchyma B. Sclerenchyma C. Xylem parenchyma D. Meristem
Which statement best describes a colloid?
A. A completely homogeneous molecular solution B. A heterogeneous mixture with dispersed particles that do not settle easily C. A pure substance D. A suspension whose particles settle immediately
Two equal and opposite horizontal forces act on a stationary object. What is the net force?
A. Equal to one force B. Double one force C. Zero D. Cannot be determined

Answers: 1-C, 2-C, 3-B, 4-B, 5-C.

4-Week Class 9 Science Olympiad Practice Plan

Week	Focus	Target
1	Attempt this mixed paper and classify errors into Biology, Chemistry, Physics and reasoning.	Identify the weakest subject and repeated error type.
2	Revise two weak chapters from the current subject pathway and solve fresh concept questions.	Correct conceptual gaps before more timed papers.
3	Attempt the current 2026 sample paper for Biology, Chemistry or Physics under timed conditions.	Improve accuracy, diagrams, calculations and pacing.
4	Review with the current answer key, then attempt the corresponding previous-year paper.	Reduce repeated mistakes and improve consistency.

Class 9 Science Error-Log Checklist

Question/topic: write the chapter or concept tested.
Error type: concept, calculation, diagram, reading, guessed answer or time pressure.
Why it happened: missing knowledge, careless step, misunderstood wording or weak recall.
Correction: write the correct principle in one or two lines.
Fresh practice: solve at least one new question on the same idea.
Recheck date: return to the concept after several days to see whether the mistake repeats.

A good Olympiad error log tracks why an answer was wrong, not only which option was correct. Repeated error patterns are more useful than the raw score when planning revision.

Related Class 9 Science Olympiad Resources

Class 9 Science Olympiad Sample Paper FAQs

Is this the current 2026 Class 9 Science exam paper?

No. No. These are original practice questions, not an official 2026 examination. For official exam formats and papers, choose the current SCO Biology, Chemistry or Physics resources.

Why is a mixed-science paper still useful?

It quickly reveals whether the student’s weakest area is Biology, Chemistry, Physics or general reasoning. That makes it useful as a diagnostic before moving into subject-specific current practice.

How can I check my answers?

Each practice question above includes its correct choice and a written explanation. Work through the steps yourself first, then compare your method with the solution.

What should I do after this paper?

Choose the weakest subject, revise the related chapters, attempt its current 2026 sample paper, review with the answer key and then complete the current previous-year paper.