SUMMATIVE ASSESSMENT - I (2011) Lakdfyr ijh{kk&i (2011) 570039 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 five questions of five marks category. Only one option in such questions is to be attempted. iv). All questions to 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 ikwap 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. Iron objects acquire reddish brown coating when left exposed to moist air. Name the chemical Page 1 of 18
process responsible for this coating and the red coating formed. 2. We apply paint on iron grills. Why? 3. Name the major source of energy that largely fulfills the growing demand for energy in our country. 4. Keeping the potential difference constant the resistance of an electric circuit is doubled. State the change in the reading of an ammeter connected in the circuit. 5. What are amphoteric oxides? Choose the amphoteric oxides amongst the following oxides. Na 2 O, ZnO, Al 2 O 3, CO 2, H 2 O Na 2 O, ZnO, Al 2 O 3, CO 2, H 2 O 6. What is bleaching powder? How is it prepared? List two uses of bleaching powder. X YSO X SO Y 7. 4 4 Y XSO No reaction 4 Out of the two elements, X and Y, which is more reactive and why? X YSO X SO Y Y XSO 4 4 4 Page 2 of 18
X Y 8. A metal X when dipped in aqueous solution of Aluminium Sulphate no reaction is observed whereas when it is dipped in the aqueous solution of ferrous sulphate the pale green solution turns colourless. Identify metal X and justify your answer giving chemical equations for the reaction and no reaction. X X 9. Write two points of difference between aerobic and anaerobic respiration. 10. Give the disadvantages of constructing big dams across the river. How does construction of dams across the river get linked with production of green house gases? 11. How would the reading of (V) change if it is connected between C and D? Justify your answer. (V) C D 12. In the figure below, identify the poles marked P and Q as north pole or south Pole. Give reason for your answer. Page 3 of 18
P Q 13. Three 2 resistors, A, B and C, are connected as shown in figure with a source of 6 V; calculate the total resistance and current in the circuit. 2 6 V 14. Identify the substance oxidized, substance reduced, oxidizing agent and reducing agent in the following reaction : ZnO C Zn CO Packets of potato chips are flushed with nitrogen gas, why? Page 4 of 18
ZnO C Zn CO 15. A blue colour salt becomes white on heating. Give reason for the above observation. What happens when we add water to the salt which is obtained after heating. Also write its formula. 16. The ph of the mouth of a person is lower than 5.5. What changes will occur in his mouth? How can these changes be controlled? Write any two measures. ph 5.5 17. Draw the labelled structure of a neuron and explain the function of any two of its parts. 18. Why does the shoot of the plant bend towards light when it is kept inside a cardboard box with a small hole. 19. List any four characteristics of a good source of energy. How can the burning of fossil fuels cause acid rain? 20. A 12V battery is connected to the arrangement of resistors as in the circuit diagram shown below. Calculate : (i) (ii) The total effective resistance of the arrangement The total current flowing in the circuit Page 5 of 18
12V (i) (ii) 21. A copper wire has a radius of 1mm and resistivity of 1.6 10 8 m. What will be the length of this wire required to make its resistance 10? 1mm 1.6 10 8 m 10 22. A metallic conductor is suspended perpendicular to the magnetic field of a horse shoe magnet. The conductor gets displaced towards left when a current is passed through it. What will happen to the displacement of the conductor if the : (i) current through it is increased? (ii) horse shoe magnet is replaced by another stronger horse shoe magnet? (iii) direction of current through it is reversed? Page 6 of 18
(i) (ii) (iii) 23. In what forms are the metals found in nature? With the help of examples explain how metals react with oxygen, water and dilute acids. Also write chemical equations for the reactions. OR With reference to electrolytic refining of impure copper, answer the following : Draw a neat and labelled diagram required for the purpose. What is the electrolyte used? Name the cathode and anode used? What happens at cathode and anode? 24. Draw the diagram of human heart and label the following parts which (i) (ii) (iii) (iv) receives deoxygenated blood from vena cava, send deoxygenated blood to lung through pulmonary artery, receives oxygenated blood from lungs and sends oxygenated blood to all parts of the body through aorta. What does the blood consist of? Write two functions of blood. Page 7 of 18
(i) (ii) (iii) (iv) OR Draw neat diagram of respiratory system and label the following parts. (i) (ii) (iii) (iv) lungs, trachea, bronchus, diaphragm, Name the respiratory pigment in human beings and discuss its role. Why is the rate of breathing in aquatic organisms much faster than that in terrestrial organisms? (i) (ii) (iii) (iv) 25. With the help of a labelled diagram, explain the distribution of magnetic field due to a current through a circular loop. What is a solenoid? Draw the pattern of magnetic field formed around a current carrying solenoid. Compare this field to that of a bar magnet. Page 8 of 18
OR Explain an activity to show that a current carrying conductor experiences a force when placed in a magnetic field. State the rule which gives the direction of force acting on the conductor. An electron moves perpendicular to a magnetic field as shown in the figure. What would be the direction of force experienced on the electron? SECTION B / ' ' 26. If a ph paper is dipped in a grape juice solution, what will be the possible colour of the ph paper? Deep red Blue Orange Violet ph ph 27. Two solutions A and B were found to have ph value of 6 and 8 respectively. The inference which can be drawn is : The stength of solution B is higher than that of A. A is an acid while B is base. Page 9 of 18
both are acidic solutions. both are basic solutions. A B ph 6 8 B A A B 28. Prachi added dil. HCl to a test tube containing zinc granules and noted the following observations : (i) (ii) (iii) The zinc surface became dull and black. A gas evolved which burnt with a pop sound. The solution remained colourless. The observations found correct are I and II II and III III and I I, II and III HCl (i) (ii) (iii) I II II III III I I, II III 29. To show that iron is more reactive than copper, the correct procedure is to : prepare ferrous sulphate solution and dip copper strip in it. prepare copper sulphate solution and dip iron strip in it. add dil. nitric acid on both strips. heat iron and copper strips both. Page 10 of 18
30. When an iron nail, rubbed with sand paper, is dipped completely for some time in copper sulphate solution, we observe that copper gets deposited on the nail. First on the lower part of the nail and proceeds to the upper part, First on the upper part of the nail and proceeds to the lower part, On the entire surface of the nail, On the nail in small patches. 31. Which of the following devices would you use to maintain potential difference between two points of a conductor? A rheostat A cell A voltmeter An ammeter 32. Using the following measuring instruments, the best pair made for carrying out experiment to determine resistance of a resistor of nearly 30 is : Milliammeter (A 1 ) : Range 0-100 ma, Least count 20 ma. Page 11 of 18
Milliammeter (A 2 ) : Range 0-500 ma, Least count 5 ma. Voltmeter (V 1 ) : Range 0-3 V and Least count 0.05 V. Voltmeter (V 2 ) : Range 0-2 V, and Least count 0.04 V. A 1 and V 1 A 1 and V 2 A 2 and V 2 A 2 and V 1 30 (A 1) : 0 100 ma 20 ma. (A 2) : 0 500 ma 5 ma. (V 1) : 0 3 V 0.05 V. (V 2) : 0 2 V 0.04 V. A 1 V 1 A 1 V 2 A 2 V 2 A 2 V 1 33. In a milliammeter, there are 20 divisions between 400 ma mark and 500 ma mark. The least count of the milliammeter is. 0.5 ma 5 ma 10 ma 50 ma. 400 ma 500 ma 20 0.5mA 5mA 10 ma 50mA 34. In the experiment on finding the equivalent resistance of two resistors connected in parallel three students connected the voltmeter in their circuits in three different ways X, Y and Z shown here : The voltmeter has been correctly connected in cases X and Y only cases Y and Z only Page 12 of 18
cases Z and X only all the three cases X, Y, Z X Y Y Z Z X 35. The correct way of connecting the ammeter and voltmeter with a series combination of two resistors in a circuit for finding their equivalent resistance in shown in diagram : Page 13 of 18
A B C D 36. A student performed starch test on a leaf. Four steps involved in the test are shown below : The correct sequence of steps should be (iv), (iii), (i), (ii) (i), (ii), (iv), (iii) (ii), (iii), (iv), (i) (i), (iii), (iv), (ii) Page 14 of 18
(iv), (iii), (i), (ii) (i), (ii), (iv), (iii) (ii), (iii), (iv), (i) (i), (iii), (iv), (ii) 37. The teacher instructed a student to place a healthy potted shoe flower plant in a dark room for 24 hours prior to an experiment on photosynthesis. The purpose of placing it in a dark room is to increase the intake of CO 2. activate the chloroplasts in the leaves. destarch the leaves. denature the enzymes in the leaves. 24 CO 2 38. In preparing temporary stained mount of a leaf peel, the extra stain is removed by : Washing with stained water. Soaking with filter paper. Absorbing with cotton wool. Page 15 of 18
Washing with calcium chloride solution. 39. In the following sketch of the stomatal apparatus, the parts I, II, III and IV were labelled differently by four students. The correct labelling out of the following is : I guard cell, II stoma, III starch, granule, IV nucleus I cytoplasm, II nucleus, III stoma, IV chloroplast I guard cell, II Starch, III nucleus, IV stoma I cytoplasm, II chloroplast, III stoma, IV nucleus I, II, III IV I II III IV I II III IV I II III IV I II III IV Page 16 of 18
40. A student has drawn the figure to show the observed condition at the end of performing the experiment to show that germinating seeds give out CO 2 during respiration. Choose the correct diagram. A B C D CO 2 A B C D 41. In the experiment demonstrating respiration in germinating seeds, the water rises in the Page 17 of 18
delivery tube because seeds use up oxygen in the flask. CO 2 is given out by germinating seeds. germinating seeds suck the water from the beaker. a partial vacuum is created as CO 2 is absorbed by KOH. CO 2 KOH CO 2 Page 18 of 18