Q. 2. Write the functional group present in the compound CH3NH2 and name it. 1
Q. 5. How can we locate the Pole Star in the sky at night? 1
Q. 6. What are ‘Jovian planets’? Write any two characteristics of Jovian planets. 2
Q. 8. What is the difference between ‘concrete cement’ and ‘reinforced concrete cement’ structures as used in building industry? Which one of these two structures is more resistant to force and which one is preferred for building floors? 2
Q. 11. Write chemical equations for reactions taking place when:
a) Manganese dioxide is heated with aluminium powder.
b) Steam is passed over hot iron.
c) A mixture of ammonia and oxygen is passed over platinum heated to 1073K. 3
Q. 12. Give reasons for the following: 3
a) Na, K and Ca metals form hydrides by combination with hydrogen gas, but most other metals do not.
b) Aluminium easily combines with oxygen but still it can be used for making kitchen utensils.
c) Dried fruit plastic bags sold in the market are filled with nitrogen gas instead of air
Q. 16. An 8 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 25 cm. The distance of the object from the lens is 30 cm Find the.
(b) nature and
(c) size of the image formed. 3
Q. 24. As a pollutant of the atmosphere, carbon monoxide is considered to be more dangerous than carbon dioxide. Why 2
Q. 25. What are transgenic organisms? Which property of DNA is used as a tool in genetic engineering? 2
Q. 27. What is the function of hepatic caeca in a grasshopper’ Draw a labelled diagram showing the digestive system of a grasshopper. 3
Q. 29. Name the two major divisions of the autonomic nervous system in man in the human body what is the effect of the following systems: 3
a) Blood vessels b) Urinary bladder.