8th Science Annual Examination (2018-19)
Time: 3 hours
- All questions are compulsory.
- Read the paper carefully and write all your answers only on the Answer Sheets provided separately.
- Draw the diagrams neatly only with a pencil.
Very short answer questions: [1×3=3]
Question: 1. Which gland is known as the master switch board?
Question: 2. What is menopause?
Question: 3. Write the ionic form of Mg and O.
Short answer questions (I): [2×6=12]
Question: 4. Briefly explain how a bats catches its prey.
Question: 5. With the help of a simple diagram explain what happens to light when it passes from a denser medium to a rarer medium.
Question: 6. Who is responsible for the gender of the baby? Explain.
Question: 7. Give two points of difference between chloroplast and chromoplast.
Question: 8. The elephant weighs 10,000 N stands on one foot of area 1000 cm². How much pressure would it exert on the ground?
Question: 9. Explain why hydrogen is not used as a domestic fuel?
Short answer questions (II): [3×10=30]
Question: 10. Two tyres of a tractor are very wide and huge. Why? What is the SI unit unit of pressure?
Question: 11. Where is image formed in our eyes when we seen (i) a nearby object (ii) a far off object. Explain.
Question: 12. How does shrillness or pitch is affected by frequency? Explain giving examples.
Question: 13. Illustrate the harmful effects of excessive use of fertilizers, pesticides, insecticides etc. on the quality of soil.
Question: 14. What is animal husbandry? List some food products that we get from animals.
Question: 15. How is rapid combustion different from spontaneous combustion? Explain giving examples.
Question: 16. Are the cells present in your body eukaryotic? Give reason for your answers.
Question: 17. Why are liquid fuels better than solid fuels? (three points)
Question: 18. Study the circuit carefully. Will the bulb glow? Why? Will it glow if lemon juice is replaced with salt water? [1+1+1]
Question: 19. Explain reproduction in hydra with the help of diagrams.
Question: 20. Explain any three physical changes that take place in females during puberty.
Long answer questions: [5×7=35]
Question: 21. Briefly explain how we extract petrol from petroleum. Draw diagram to support your answer.
Question: 22. (a) Identify A,B,C,D,E and F
(b) What is the function of E and F
Question: 23. List different ways of sowing seeds. Explain any one method in detail. What precautions should we take while sowing seeds?
Question: 24. (a) Identify the process taking place in the given cell.
(b) Identify the anode and cathode.
(c) Name the electrolyte.
(d) What would happen if the thin plate is replaces with a wooden stick?