Tamil Nadu Class 9 Science Model Paper 1 — Samacheer Kalvi

Instructions

• Section A: 15 × 1 = 15 marks
• Section B: 8 × 3 = 24 marks (Answer any 8 out of 10)
• Section C: 4 × 5 = 20 marks (Answer any 4 out of 5)
• Section D: 1 × 16 = 16 marks (PTA questions / Extended response)

Section A — One Mark Questions (15 marks)

1. State the SI unit of electric current. 2. Define displacement. 3. What is the principle behind a hydraulic press? 4. Who discovered the magnetic effect of current? 5. Name the fourth state of matter. 6. Write the electronic configuration of Chlorine (Atomic No. 17). 7. What is the minimum distance for an echo to be heard? 8. State the law of conservation of mass. 9. Define transpiration. 10. Name the largest phylum in the animal kingdom. 11. Which vitamin deficiency causes Scurvy? 12. What is the general formula for alkenes? 13. Name the part of the brain responsible for balance and coordination. 14. Define significant figures. 15. State Ohm's law in words.

Section B — Short Answer Questions (3 marks each, answer any 8)

1. A car starts from rest and reaches 30 m/s in 10 seconds. Calculate (a) acceleration and (b) distance covered. 2. Distinguish between physical and chemical changes with two examples each. 3. Explain the three characteristics of sound: pitch, loudness, and quality. 4. State and explain Pascal's law with one application. 5. Write the electronic configurations of Na (11) and Cl (17). What are their valencies? 6. Distinguish between Kwashiorkor and Marasmus. 7. Draw and label the parts of a neuron. 8. Explain the factors that affect the rate of evaporation. 9. Distinguish between monocots and dicots with three differences. 10. A 100 W bulb is used for 8 hours daily for 30 days. Find the total energy consumed in kWh.

Section C — Long Answer Questions (5 marks each, answer any 4)

1. Derive the three equations of motion graphically using a velocity–time graph. 2. Describe the Bohr model of the atom. State its postulates. Write electronic configurations of the first 10 elements. 3. Trace the history of periodic classification of elements from Dobereiner to Moseley. Describe the modern periodic table. 4. Explain the process of photosynthesis with the equation. What are the factors that affect it? 5. Describe the five classes of vertebrates with two features and two examples each.

Section D — Extended Response (16 marks)

Choose one of the following and write a detailed answer:

Option 1: Explain the heating effect and magnetic effect of electric current. Give the applications of each and describe one experiment to demonstrate each effect.

Option 2: Write a detailed note on the classification of plants (Thallophyta to Angiosperm) with features, examples, and their importance. Include a diagram of the plant cell.

Time Management Plan

After the Paper — Correction Plan

Mark every wrong answer in one of these categories:

• Concept not understood
• Formula not remembered
• Diagram not practised
• Careless mistake (units, spelling)

Revise each category separately before the actual exam.