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1. Zinc granules are placed in each of the four solutions A, B, C and D as shown below decolourisation would be observed in Alumanures Zine Copper Ferrous sulphate sulphate suiphale sulphate solution solution ~~ solution § — solution a) [B] and [D] c) [C] and [D] 2. BaClp + NaySO4 — BaSOq + 2NaCl. It is type of: a) Both Precipitation reaction and Double displacement reaction c) Decomposition reaction 3. Which of the following conducts electricity? Rainwater, distilled water, potable water. a) rain water, distilled water c) distilled water, potable water Section A b) [A] and [C] d) [A] and [B] b) Double displacement reaction d) Precipitation reaction b) rain water, potable water d) Rain water, distilled water, potable water {1] [1] (1] 4. A hydrocarbon with molecular formula C 4H 49 has: a) 10 covalent bonds b) 7 covalent bonds ¢) 13 covalent bonds d) 6 covalent bonds > During smelting, an additional substance is added which combines with impurities to form a fusible product known as: a) Flux b) Slag c) Gangue d) Mud 6. Dried fruit plastic bags sold in the market are filled with: a) Hydrogen gas b) All of these c) Helium gas d) Nitrogen gas 7. Ethane - with the molecular formula C2H¢ has a) 9 covalent bonds b) 8 covalent bonds ¢) 7 covalent bonds d) 6 covalent bonds 8. Which liquid did a student use for putting a drop on the slide before placing the coverslip while preparing a temporary mount of leaf epidermal peel? a) Water b) Iodine c) Glycerine d) Safranin 9. A zygote which has an X-chromosome inherited from the father will develop into a a) either boy or girl b) girl c) X- chromosome does not determine the sex d) boy of a child 10. A bisexual flower contains: a) Stamens only b) Both stamens and carpels. c) Carpels only d) Either stamens or carpels 11. Two pink colored flowers on crossing resulted in 1 red, 2 pink, and 1 white flower progeny. The nature of the : cross will be | a) self pollination b) double fertilisation ©) no fertilisation d) cross fertilisation 12. During deficiency of oxygen in tissues of human beings, pyruvic acid is converted into lactic acid in the (y 1] 184) (J {1] itt) (] 20. rat 22, 23. 24. 25. 26. 2). 28. c) Ais true but R is false. d) A is false but R is true Assertion (A): Man is an omnivore. Reason (R): Man eats food products obtained from both plants and animals. a) Both A and R are true and Ris. the correct b) Both A and R are true but R is not the explanation of A. correct explanation of A. ¢) A is true but R is false. d) A is false but R is true. Section B Write the balanced chemical equation for the following: a. Methane is burned insufficient air. b. Ethanol is treated with sodium. c. Ethanoic acid is reacted with sodium hydroxide. d. Ethanoic acid is treated with sodium carbonate. e. Ethanol is mixed with ethanoic acid in the presence of an acid. What is puberty? Mention any two changes that are common to both boys and girls in early teenage years. Plants excrete waste products from their body by various means. Justify the above statement. OR Why is it not advisable to sleep under a tree at night while resting under it during mid-day is not bad? ‘A cconcave lens has focal length of 15 cm. At what distance should the object from the lens be placed so that it forms an image at 10 cm from the lens? Also, find the magnification produced by the lens. Carnivores cannot be self-dependent and have to depend on herbivores. Explain. OR Calculate the percentage of energy that will be available to big fish in the following foods chain: Small algae, zooplankton, fish, big fish.The energy available to small algae from sun is 10000 J. Name four colours of the spectrum of white light which have wavelengths longer than blue light. Section C Nikita took Zn, Al, Cu, Fe, Mg and Na metal and put each metal in cold water and then hot water. She reacted the metal with steam (i) Name the metal which reacts with cold water. (ii) Which of the above metals react with steam? (iii) Name the metal which reacts with hot water. (iv) Arrange these metals in order of increasing reactivity. In what forms are metals found in nature? With the help of examples, explain how metals react with ox xygen, ‘water and dilute acids. Also, write chemical equations for the reactions. zs OR Give reasons for the following: i, Generally no hydrogen gas is evolved when metals react with dilute nitric acid. ii. Sodium hydroxide solution cannot be kept in aluminium containers iii. Sil i ily wi il ov metal does not combine easily with oxygen but silver Jewellery tarnishes after some time. iv, Sodium is obtained by the electrolysis of its molten chloride and not from its aqueous solution, y, Aluminium reacts with dilute hydrochloric acid slowly in the beginning. _ Describe the process of urine formation in kidneys, {i] {2] {2} [2] (2] (21 (2] (3] (31 (3) 3. 35. Differentiate between virtual image formed by & concave mirror i, Who provided the evidence of DNA as genetic material? iii. List three important features of double helical model of DNA. re ii, Why DNA is called polynucleotide? | and of a convex mirror. of |. Write the relationship between electrical resistance and electrical resistivity for a metallic conductor cylindrical shape. Hence derive the SI unit of electrical resistivily, s { o sect Axi ii. Find the resisivity of the material of a metallic conductor of length 2m and area of cross section 1.4 m2. The resistance of the conductor is 0.04 ohm. {3} | Study the following circuit and answer the questions that follows: av « 4 —$<<$—{1) C t ; wa 360 i. How much current Is flowing through a. 10M and b. 150 resistor? ii, What is the ammeter reading? Section D Write the structural formulae of all the isomers of hexane. 15) OR An organic compound A having the molecular formula CgHg0 is a liquid at room temperature. The organic liquid A ‘yeacts with sodium metal to evolve a 235 which burns causing a little explosion. When the organic liquid A is heated with concentrated sulphuric acid at 170°C, it forms a compound B which decolorises bromine water. Compound B adds on one molecule of hydrogen im the presence of Nias catalyst to form compound C which gives substitution reactions with chlorine. i, What is compound A? ji. What is compound B? ili. What type of reaction occurs when A is converted into B? iy, What is compound C? xy, What type of reaction takes place when B is converted into C? With the help of suitable diagrams exp! grams explain the various steps of budding in Hydra. {5] Hydra & : Budding In Hydra Set eae OR What are reflex actions? Give e i eee, xamples? Explain reflex arc by an exampl 7 of the following cases to show the ' ple with labelled diagram? . ‘ormal : Life) n of image, when the object is placed: \ ——_——_—=_— the stem is it? 29 Read the text carefully and answer the questions: Take two different coils of copper wire having large number of turn: them over a non-conducting roll as shown in the given figure. Connect the Coil-1, having large numbe in series with a battery anda plug key. Also connect the other Coil-2 with a galvanometer. Coat Coll-2 Galvancrneter fi) Explain the reason for the current which fs res| (ii) Define the phenomenon involved in this case- (iii) State what is observed in the galvanometer, when 1. the key is closed. 2. the key is opened. OR s, say 50 and 100 turns respectively. Insert r of tums, ponsible for the deflection in the galvanometer- A coil AB of copper wire is connected to a galvanometer as shown in the figure. What is observed when N-pole of a strong bar magnet Is WO “a | N 3 ) {. pushed into the coil? IL held stationary inside the coil? State the reason for each observation. 14) 
