CBSE sample paper9 class x science 2008

---------------------------------------------------------------------------------------------------www.cbseguess.com Other Educational Portals www.icseguess.com | www.ignouguess.com | www.dulife.com | www.magicsense.com SCIENCE SAMPLE PAPER 2008 Maximum marks: 60 Time : 21/2 hours. 1. What is amalgam ? Mention the constituents of solder. (1/2 + 1/2 = 1) 2. Why the mixture of silver chloride turns grey when exposed to sunlight? (1) 3. Why we cannot see any object placed closer than 25cm? (1) 4. Give any 2 uses of electromagnets. (1) 5. Write the main products when brine solution is electrolysed. (1) 6. What is the main advantage of AC generator over DC generator? (2) 7. Why graphite electrodes are used in the electrolysis of sodium chloride solution? (2) 8. Why curd and other food stuff should not be stored in brass vessels? (3) 9. Write Oestord’s experiment in brief? (3) 10. A wire of P resistance is stretched twice its length. (i) What happens to its thickness and temperature? (ii) What happens to its resistivity? Give the SI unit of resistivity. (3) 11. Ist GROUP 2nd GROUP 17th GROUP 18th GROUP Ist PERIOD A F 2nd PERIOD C 3rd PERIOD D B (i) Name a non-metal having valency 0. (ii) Name the group of elements present in the group B. (iii) What is the atomic number of the group A. (iv) Out of A and D which has a bigger atomic radius and why? 12. Why were the noble gases given separate positions in the periodic table? (3) 13. Mention the main features of the magnetic field lines around a current carrying circular loop. (3) 14. Give the brief advantages of biomass energy with comparison to energy obtained from wood. (3) This watermark does not appear in the registered version -http://www.clicktoconvert.com---------------------------------------------------------------------------------------------------www.cbseguess.com Other Educational Portals www.icseguess.com | www.ignouguess.com | www.dulife.com | www.magicsense.com 15. Give reasons for the following: (a) Plaster of Paris should be stored in Moisture proof container. (b) Acids do not show acidic properties during lack of moisture. (c) Charcoal is considered to be better than wood. (d) Household circuits are connected in parallel. (e) Fuse wire is used as a safety device in electric circuits. OR How are electromagnets formed? Give the construction and working of a DC generator. (5) 16. (i) State Right hand rule of Fleming. (ii) Give the relationship between magnetic field , current and motion of conductor. (iii) Give short notes about the characteristic properties of periods. ( 2 + 1 +2 = 5) OR Compare and contrast ethanol and ethanoic acid and also mention about their physical properties. What is an ester? Give its main use. ( 3 + 1 + 1 = 5) BIOLOGY 17. What is the role of mucus in our stomach ? (1) 18.W hat is a neuro-muscular junction? Add a note about neuro-transmittor. (1) 19. How are small intestine designed to absorb the digested food? ( 1 ) 20. What are olfactory lobes? What is a cerebro-spinal fluid. (1) 21.Mention three main points of differences between ozone and O2. (2) 22. State in brief the 10% law of energy transfer in a food chain. (2) 23. Explain why the lungs contain a residual volume of air. (2) 24. Explain Darwin’s theory of natural selection. (3) This watermark does not appear in the registered version -http://www.clicktoconvert.com---------------------------------------------------------------------------------------------------www.cbseguess.com Other Educational Portals www.icseguess.com | www.ignouguess.com | www.dulife.com | www.magicsense.com 25. Why we need to conserve our resources like coal and petroleum ? (3) 26. Describe the water harvesting system in Khadins with reference to the water scarcity prevailing in the country. OR Draw and explain the structure and function of each and every organ in the excretory system in human beings. (4) ALL THE BEST This watermark does not appear in the registered version -http://www.clicktoconvert.com