Indian School Al Wadi Al Kabir s2

INDIAN SCHOOL AL WADI AL KABIR DEPARTMENT OF SCIENCE 2016-17 CBSE BOARD PAPER – SA II – SCIENCE ( 086)

1. Derive the formula of the compound formed between Na+ and SO42 .(1) 2. What is the charge and mass of an electron ? (1) 3. What is the limitation in making anti-viral drugs which does not apply to antibacterial drugs ? (1) 4. Do, molecules of air undergo displacements due to propagation of sound waves through them ? Justify your answer. (2) 5. Define potential energy. Write an expression for potential energy. Write the SI unit of potential energy. (2) 6. (a) When 10g of sulphur is burnt in 10g of oxygen 20g of sulphur dioxide is produced ? Find the mass of sulphur dioxide formed on burning 20g of sulphur in 30g of oxygen ? Justify your answer by stating the law which governs your answer. (3) (b) State the postulate of Dalton’s atomic theory which explains the above law. 7. Show the electron distributions of a magnesium atom and a magnesium ion diagrammatically and also give their atomic numbers. (3) 8. (a) What are valence electrons ? Give example. (b) State the property of an element which can be used for its identification. (3)

9. Earthworm, Leech, Prawn and Centipede (scolopendra) have segmented body organization. Would you place them in the same phylum ? If yes, name the phylum. If no, name the phyla and state two characteristics based on which we classify them in different phyla. (3) 10. According to a newspaper report, some areas in Delhi received grey coloured water in their taps. It was reportedly due to mixing of contents at some points due to leakage in sewer and water supply pipes. Which kind of diseases are likely to spread due to such problems and why ? Give two specific names of diseases that can thus be spread. (3) 11. Classify the following organisms into their respective kingdoms as per Whittaker’s five kingdom classification : Amoeba, Euglena, Birds, Herbs, Cats, Lactobacillus. (3) 12. Define potential energy. An object of mass 9 kg is at a certain height above the ground. If the potential energy of the object at this height is 540J, find the height of the object above the ground. (g=10 m/s2) (3) 13. A boat having a length 3 m and breadth 2 m is floating on water. The boat sinks by 1 cm, when a man gets on it. What is the mass of the man? (3) 14. Which part vibrates in the following musical instruments vibrate to produce sound? (a) Shahnai (b) Flute (c) Piano Also identify the type of wave produced in each case. (3) 15. (a) Define relative density. (b) Find the relative density of mercury if its density is 13.6x103kg/m3. (3) 16. Ravi lives in a village and his school is 5 km away from his house. His father suggested him to buy a scooty to go to school but Ravi opted for a bicycle instead. (i) What kind of energy transformation takes place while Ravi rides a bicycle ? (ii) What do you conclude about Ravi's nature ? (iii) Suggest one way in which you can contribute to the environment. (3)

17. (a) Define atomic mass unit. (b) Which two reasons prompted the scientists to choose oxygen as a reference initially ? (c) What is meant by the fact that the atomic mass of nitrogen is 14 ? (5) 18. Draw a diagram of Euglena and label the following parts : Flagellum, photoreceptor, eyespot, chloroplast, nucleus, contractile vacuole. (5) 19. (a) ‘Making antiviral medicines is harder than making antibacterial medicines’. Explain this statement. (b) How is the antibiotic penicillin effective against many bacteria ? (5) 20. (a) Write an expression for potential energy of an object with mass a placed at height h. Write SI unit of potential energy. (b) Find the ratio of changed potential energy to the original potential energy if the mass of the object is halved. (c) Find the ratio of changed potential energy to the original potential energy if the object is now placed at half of its original height from the ground. (5) 21. Define kinetic energy. Write an expression for kinetic energy and the SI unit of kinetic energy. Two cars are moving with velocities 36 km/h and 54 km/h on a highway. Find the ratio of their kinetic energies if mass of the cars is 400 kg and 600 kg respectively. (5)

Section – B(1 MARK EACH)

22. The velocity of a sound wave, which covers a distance of 9.6 metres in 0.4 seconds is : (a) 27 m/s (b) 24 m/s (c) 2.43 m/s (d) 24.3 m/s 23. A circular pillar of radius 25 cm supports a weight of 484 N. The pressure exerted on the pillar is : (a) 2464 Pa (b) 121 Pa (c) 2000 Pa (d) 2500 Pa 24. Which of the following will cause the change in speed of the pulse : (i) increasing distance between two ends of slinky (ii) decreasing number of turns in slinky (iii) changing the material of the slinky (iv) changing the radius of each turn of slinky

(a) (i) and (iii) (b) (ii) and (iv) (c) (iii) and (iv) (d) (ii) and (iii) 25. After observing the specimen of a plant four students sketched it as shown above and identified the division of the planta kingdom to which it belongs. The correct identification is : (a) Pteridophyta (b) Bryophyta (c) fungi (d) algae

26. Four students P, Q, R and S carried out different chemicals reactions in the chemistry laboratory to verify the law of conservation of mass. (P) Heated ferrous sulphate crystals in a China dish. (Q) Added barium chloride solution of sodium sulphate solution in a sealed container. (R) Passed carbon dioxide gas through lime water in a conical flask. (S) Added dilute hydrochloric acid to Zinc granules in a test tube. Which student will give the best result ? (a) P (b) Q (c) R (d) S 27. A student carried out a chemical reaction between 14.55 g of aqueous silver chloride and 8.5 g of aqueous sodium nitrate. 5.85 g of sodium chloride was formed. What is the mass of silver nitrate formed ? (a) 17.5 g (b) 17.2 g (c) 18.05 g (d) 18 g 28. Dicotyledonous plants often have : (a) cambium absent (b) isobilateral leaves (c) floral parts in units of three (d) reticulate venation 29. After observing the specimens of two leaves four students A, B, C and D reported as :

A : Both A and B are leaves of dicotyledonous plant B : Both A and B are leaves of monocotyledonous plant C : A is of monocotyledonous plant and B is of dicotyledonous plant D : B leaf is of monocotyledonous plant and A is of dicotyledonous plant

Correct report is given by student : (a) A (b) B (c) C (d) D 30. The stage in the life cycle of a mosquito in which the organism is very active and requires a lot of food is : (a) Pupa (b) Larva (c) Adult (d) Egg 31. A student notes down the observations in the two spring balances and the measuring cylinder as shown below. How much is the volume of the solid ? Mass of the solid is 60 g then what will be the density of the material of the solid ?

32. What is meant by relative density of a material ? Give its SI units. (2) 33. Draw the diagram of an earthworm and write its two adaptive features. (2)

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