SUMMATIVE ASSESSMENT - I (2011) Lakdfyr ijh{kk&i (2011) 570041 SCIENCE / fokku Class X / & X Time allowed : 3 hours Maximum Marks : 80 fu/kkzfjr le; % 3?k.Vs vf/kdre vad % 80 General Instructions : i). The question paper comprises of two sections, A and B. You are to attempt both the sections. ii). All questions are compulsory. iii). There is no overall choice. However, internal choice has been provided in all the three questions of five marks category. Only one option in such questions is to be attempted. iv). All questions of section A and all questions of section B are to be attempted separately. v). Questions 1 to 4 in section A are one mark questions. These are to be answered in one word or one sentence. vi). Questions 5 to 13 in section A are two marks questions. These are to be answered in about 30 words each. vii). Questions 14 to 22 in section A are three marks questions. These are to be answered in about 50 words each. viii). Questions 23 to 25 in section A are five marks questions. These are to be answered in about 70 words each. ix). Questions 26 to 41 in section B are multiple choice questions based on practical skills. Each question is a one mark question. You are to select one most appropriate response out of the four provided to you. a lkeku; funsz k % (i) bl iz u i= dks nks Hkkxksa, Hkkx v vksj Hkkx c es ckavk x;k gsa vkidks nksuksa Hkkxksa ds iz uksa ds mrrj fy[kus gsaa (ii) lhkh iz u vfuok;z gsaa (iii) iwjs iz u i= ij dksbz p;u izkir ugha gs ijurq ikap&ikap vadks ds rhu iz uksa esa Hkhrjh p;u fn;k x;k gsa bu iz uksa esa vki dsoy,d Hkhrjh p;u dks mrrj fy[kus ds fy, pqu ldrs gsaa (iv) vkidks Hkkx v vksj Hkkx c ds lhkh iz uksa ds mrrj i`fkd&i`fkd fy[kus gksaxsa (v) Hkkx v ds iz u la[;k 1 ls 4 ds iz u,d&,d vad ds gsaaa buds mrrj,d kcn vfkok,d okd; esa nsaa (vi) Hkkx v ds iz u la[;k 5 ls 13 ds iz u nks&nks vadksa ds gsaa buds mrrj yxhkx 30&30 kcnksa esa nsus gsaa (vii) Hkkx v ds iz u la[;k 14 ls 22 ds iz u rhu&rhu vadksa ds gsaa buds mrrj yxhkx 50&50 kcnksa esa nsus gsaa (viii) Hkkx v ds iz u la[;k 23 ls 25 ds iz u ikap&ikap vadksa ds gsaa buds mrrj yxhkx 70 kcnksa esa nsus gsaa (ix) Hkkx c ds iz u la[;k 26 ls 41 ds iz u iz;ksxkred dks ky ij vk/kkfjr cgqfodyih iz u gsaa izr;sd iz u,d vad dk gsa fn, x;s pkj fodyiksa esa ls vkidks dsoy,d lcls mi;qdr fodyi pquuk gsa SECTION-A / ' ' 1. State the chemical change that takes place when lime stone is heated strongly. Page 1 of 16
2. Give an example of a metal which can be easily cut with a knife. 3. Mention any one feature of biogas that makes it an ideal fuel. 4. A piece of wire of resistance R is cut into two equal parts. If these two parts are now connected in parallel, then state how the resistance and the resistivity of the combination will change. Justify your answer. R 5. Why is sodium kept immersed in kerosene? 6. What would be the colour of the solution when copper oxide and dilute hydrochloric acids are mixed? Write a chemical equation which represents that the effect of a base is nullified by an acid and vice-versa. 7. What is the colour of FeSO 4. 7H 2 O crystals? How does this colour change upon heating? Give balanced chemical equation for the changes. FeSO 4. 7H 2 O Page 2 of 16
8. Write balanced equations for the reaction of : iron with steam calcium with water. 9. Which is the internal energy reserve in plants? Do the animals have the same energy reserve? Justify your answer. 10. Write two points of limitations of using solar cookers. 11. Calculate the electrical energy consumed by a 1200W toaster in 20 minutes. 1200W 20 12. What will be the direction of the deflection of the magnetic needle when current carrying conductor is placed perpendicular to the axis of the needle? Give reason to support your answer. 13. Why do the wires connecting an electric heater to the mains not glow while its heating element does? 14. What are redox reactions? Why is the reaction between manganese dioxide and hydrochloric acid a redox reaction? Identify the substance oxidised and the substance reduced in the above reaction. Page 3 of 16
15. What is tooth enamel chemically? State the condition when it starts corroding? What happens when food particles left in the mouth after eating degrade? Why do doctors suggest use of tooth powder/tooth paste to prevent tooth decay? 16. Metal compound A reacts with dilute hydrochloric acid to produce effervescence and a gas B. The gas B extinguishes a burning candle and also turns lime water milky. Identify A and B. Write balanced chemical equations for the reactions involved. A B B A B 17. Which part of the brain controls involuntary actions? Write the function of any two regions of it. 18. What is tropism? Design an experiment to demonstrate hydrotropism with the help of diagram. 19. Biomass has been used as a fuel since ancient times, how has it been modified to function as a more efficient fuel in the recent past. 20. What would be the reading of ammeter and voltmeter in the given circuit? Page 4 of 16
21. Two conducting wires of same material, equal length and equal diameter are first connected in series and then in parallel. Compare the heat produced by the combination of resistances in two cases. 22. (i) What precautions should be taken to avoid the overloading of domestic electric circuits? (ii) An electric oven of 2 kw power rating is operated in a domestic electric circuit which has a current rating 5A. If the supply voltage is 220V, what result do you expect? Explain. (i) (ii) 2 kw 220V 5A 23. What is meant by metallurgy? State two steps associated with extraction of copper from its ore. How is impure copper purified by electrolytic refining? Draw a labelled diagram to illustrate it. Page 5 of 16
OR Write the electron dot structures of sodium, oxygen and magnesium. Show the formation of Na 2 O and MgO by transfer of electrons. List three properties of ionic compounds. Na 2 O MgO 24. With the help of suitable diagrams explain the process of nutrition in amoeba. How many times the blood goes through the heart during one cycle in fish and why? OR List the events that occur during photosynthesis. Name the respiratory pigment present in our body? Where is it present? Why are valves present in heart and veins? Page 6 of 16
25. Explain why two magnetic lines do not intersect each other. State the rule for determining the direction of the magnetic field produced around a current carrying conductor. Draw a sketch of the pattern of field lines due to a current flowing through a straight conductor. (i) (ii) OR What is a solenoid? Draw a sketch of the pattern of field lines of the magnetic field through and around a current carrying solenoid. Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right hand rule to find out the direction of the magnetic field inside and outside the loop. (ii) SECTION B / ' ' 26. A student tested the ph of distilled water using ph paper and observed green colour. After adding a few drops of dilute NaOH solution, the ph was tested again. The colour change now observed would be : blue green red orange NaOH ph ph ph 27. In an experiment to test the ph s of a given sample using ph paper, four students recorded the following observations for the sample tested by each one of them. Sample taken. ph paper colour turned to. (I) Water Blue (II) Dil. HCl Red Page 7 of 16
(III) Dil. NaOH (IV) Dil. Acetic acid Blue Orange The student who took the incorrect observation is : I II III IV ph ph (I) (II) (III) HCl NaOH (IV) I II III IV 28. Given below are certain chemical properties of substances (I) (II) It turns blue litmus red. It turns red litmus blue. (III) It reacts with zinc and a gas evolves. (IV) It reacts with solid sodium carbonate to give brisk effervescence. Which out of these properties are shown by dilute hydrochloric acid I and II only I and III only I, III and IV only II, III and IV only (I) (II) (III) (IV) Page 8 of 16
I II I III I,III IV II, III IV 29. A student added some copper sulphate crystals in water in a beaker and observed the colour of the solution obtained. The colour of the solution observed by him must be : green blue yellow pink 30. A student took solid quicklime in a china dish and added a small amount of water to it. He would hear a : pop sound a crackling sound a hissing sound no sound at all. 31. An ammeter has 20 divisions between mark 0 and mark 2A on its scale. The least count of the ammeter is : 0.02 A 0.01 A 0.2 A 0.1 A 0A 2A 20 0.02 A 0.01 A 0.2 A 0.1 A 32. Using the circuit given below, current and potential difference were measured and these values were plotted on a graph. Page 9 of 16
Which one of the following graph most correctly shows the dependance between current and potential difference? 33. The readings of current flowing through a conductor and the potential difference across its two ends are shown in the ammeter and voltmeter given below. Page 10 of 16
The resistance of the conductor would be 20 5.0 2.0 0.2 20 5.0 2.0 0.2 34. In parallel combination of resistors, two students connected the ammeter in two different ways as shown in given circuits I and II. The ammeter has been correctly connected in : circuit I only circuit II only both the circuits I and II neither of the two circuits I II Page 11 of 16
I II I II 35. For carrying out the experiment, on finding the equivalent resistance of two resistors connected in series, a student sets up the circuit as shown. On further verification he finds out that the circuit has one or more of the following faults. (i) The resistors R 1 and R 2 have not been correctly connected in series. (ii) (iii) The voltmeter has not been correctly connected in the circuit. The ammeter has not been correctly connected in the circuit. Out of these three, the actual fault in the circuit is/are : both (i) and (ii) both (ii) and (iii) only (i) only (ii) Page 12 of 16
(i) R 1 R 2 (ii) (iii) / / (i) (ii) (ii) (iii) (i) (ii) 36. Which one of the following is the combination of relevant materials required for setting up an experiment to show that light is necessary for photosynthesis? Destarched leaves, strips of black paper, starch solution and iodine crystals A potted plant, strips of coloured paper, starch solution, iodine and potassium iodide Strips of black paper, starch solution, destarched leaves and potassium iodide Strips of black paper, destarched leaves and iodine solution 37. The best result for the experiment that light is necessary for photosynthesis would be yielded by using leaves from a plant that was initially kept for over twenty four hours: in a pitch dark room. in a dark room with table lamp switched on. outside in the garden. outside in the garden covered by glass case. Page 13 of 16
24 38. While preparing a temporary mount of leaf epidermis, it is suggested that a brush instead of a sharp needle should be used to transfer the peel from petridish to slide. This is because the : sharp needle does not allow mounting of the peel. needles can be used to prevent the entry of bubbles on the mount. sharp needle may damage the cells. needle does not help in the proper transfer of peel from petridish to slide. 39. The stomatal apparatus comprises guard cells stomata and guard cell stomata, guard cells and accessory cells guard cells and chloroplast Page 14 of 16
40. In the following experimental set up a small test tube containing KOH pellets is kept in the conical flask to absorb : air in the flask. moisture in the flask. oxygen in the flask. CO 2 released by the germinating seeds during respiration. KOH Page 15 of 16
(O 2 ) CO 2 41. A student set up the apparatus for the experiment to show that CO 2 is released during Respiration. After 2 hours, he would observe that : KOH turns milky water level rises in the bent tube in the beaker. water level decreased in the bent tube in the beaker. water turns turbid in the beaker. CO 2 KOH Page 16 of 16