» CBSE Science Sample Question Paper : Set II : CBSE Sample Question Papers

Section - A

1. Name one gaseous fossil fuel.
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2. Complete the path of ray of light after reflection at the mirror in the given diagram ;
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3. Express one light year in terms oi’ SI unit of distance.
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4. Give an example of a photochemical reaction.
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5. An organic component is a constituent of beer, whisky and some cough syrup. It is produced by the fermentation of sugar. Identify the organic compound.
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6. Name any two Jovian Planets. Write their common features.
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7. A current carrying straight conductor is placed in east-west direction. What will be the direction of the force experienced by this conductor due to earth’s magnetic field ? How will this force get affected on: (a) reversing the direction of flow of current ? (b) doubling the magnitude of current ?
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8. How do we obtain information about the interior of earth ?
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9. What kind of energy transformation takes place in an electric motor ? Name any tv/o devices which use electric motor as an essential component in their working.
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10. Write the equilibrium constant expression for the following chemical reaction :
N₂(g) + O₂(g) = 2NO(g)
What does a very small value of K_c - 4.8 x 10^-31 for this reaction indicate ?
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11. An object of size 5 cm is placed at a distance of 25 cm from the pole of a concave mirror of radius of curvature 30 cm. Calculate the distance and size of the image so formed. What will be the nature of the image ?

OR
An object of size 3 cm is placed at a distance of 15 cm from a convex lens of focal length 10 cm. Calculate the distance and size of the image so formed. What will be the nature of the image ?
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12. Two electric lamps rated 100 W, 220 V and 25 W, 220 V are connected in parallel to a 220 V supply. Calculate the total electric current in the circuit.

OR
A metallic coil connected to a 220 V supply, has a resistance of 110 ohms (while hot). How long will it lake this coil to heat I kg of water from 20^°C to 70^°C? Assume that whole of heat produced by the coil is taken up by water. ( Sp. Heat capacity of water = 4186 J/kg^°C)
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13. Describe with chemical equations, what happens when : Carbon dioxide gas reacts with ammonical brine in Solvay process.
(ii) Bleaching powder is left exposed to the air containing carbondioxide gas.
(iii) A mixture of finely powdered sand and sodium carbonate is heated in a tank furnace.
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14. Give chemical tests to ;
(I) detect the presence of ethanol.
(ii) show that methanol contains an aldehyde group.
(iii) show a saponification reaction.
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15. An organic compound A having molecular formula C₂H₄O, reacts with sodium metal and evolves a gas B which readily catches fire. A also reacts with ethanol in the presence of concentrated sulphuric acid to form sweet smelling substance C used in making perfumes.
(i) Identify the compounds A, B and C.
(ii) Write balanced chemical equations to represent the conversion of :
(a) Compound A into Compound B
(b) Compound A into Compound C
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