Exercise Solutions Available
Step-by-step answers for all textbook questions in this chapter
Instructions
- Time: 2 hours 30 minutes
- Maximum Marks: 75
- Answer all questions in Section A; choose from Sections B and C as instructed.
Section A — One Mark Questions (15 × 1 = 15 marks)
1. What is the SI unit of temperature? 2. Define least count of a measuring instrument. 3. State Archimedes' principle. 4. Which mode of heat transfer does not require any medium? 5. Name the instrument used to measure electric current. 6. Write the chemical formula of water. 7. What is the atomic number of oxygen? 8. State Mendeleev's periodic law. 9. What colour does blue litmus turn in an acid? 10. Name the hardest allotrope of carbon. 11. Write the equation for photosynthesis (word equation). 12. Name the tissue that transports water in plants. 13. Which microorganism causes malaria? 14. What is a zygote? 15. Define health according to WHO.
Section B — Short Answer (5 × 3 = 15 marks)
Answer any five of the following.
16. Distinguish between contact forces and non-contact forces with two examples each. 17. Explain the three modes of heat transfer with one example each. 18. State Ohm's law. Calculate the current in a circuit with voltage 9 V and resistance 3 Ω. 19. Write the electronic configuration of sodium (Z = 11) and chlorine (Z = 17). State their valency. 20. Distinguish between physical and chemical changes with two examples each. 21. Explain the difference between aerobic and anaerobic respiration with equations. 22. Name four communicable diseases, their causative organisms, and one mode of spread each.
Section C — Long Answer (5 × 9 = 45 marks)
Answer all questions. Each question has internal choice.
23. (a) State the laws of reflection. With a diagram, explain image formation in a plane mirror. OR (b) Explain the allotropes of carbon with their structures and uses. Draw diagrams for diamond and graphite.
24. (a) Explain the structure of an atom. Describe the three subatomic particles with their charges, masses, and locations. OR (b) Describe the process of digestion in humans. Include the organs, digestive juices, and enzymes involved.
25. (a) State Archimedes' principle. Describe an experiment to verify it. Write two applications. OR (b) Explain the process of photosynthesis in detail. Include the chemical equation, conditions, and factors affecting the rate of photosynthesis.
26. (a) Explain series and parallel circuits with formulae and diagrams. Give one practical use of each. OR (b) Classify diseases into communicable and non-communicable. Describe four communicable diseases with causative organisms and prevention methods.
27. (a) Compare the properties of acids and bases. Describe neutralisation with two examples. Explain the pH scale. OR (b) Explain the methods of asexual and sexual reproduction in plants with examples.
Time Plan for This Paper
- First 10 minutes: Read all questions.
- Section A: 20 minutes.
- Section B (five questions): 30 minutes.
- Section C (five questions): 60 minutes.
- Final 10 minutes: Check units, spelling, diagrams, and equations.
Correction Checklist
After completing this paper:
- [ ] Did I write units for every numerical answer?
- [ ] Are all diagrams labelled clearly?
- [ ] Did I include textbook keywords in descriptive answers?
- [ ] Are equations balanced?
- [ ] Did I answer the correct number of questions per section?