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CBSE Sample Paper-03 (Unsolved) SUMMATIVE ASSESSMENT –II SCIENCE (Theory) Class – X Time allowed: 3 hours Maximum Marks: 90 General Instructions: a) All questions are compulsory. b) The question paper comprises of two sections, A and B. You are to attempt both the sections. c) Questions 1 to 3 in section A are one mark questions. These are to be answered in one word or in one sentence. d) Questions 4 to 6 in section A are two marks questions. These are to be answered in about 30 words each. e) Questions 7 to 18 in section A are three marks questions. These are to be answered in about 50 words each. f) Questions 19 to 24 in section A are five marks questions. These are to be answered in about 70 words each. g) Questions 25 to 27 in section B are 2 marks questions and Questions 28 to 36 are multiple choice questions based on practical skills. Each question of multiple choice questions is a one mark question. You are to select one most appropriate response out of the four provided to you. Section A 1. 2. 3. 4. 5. 6. 7. 8. How are the molecules of aldehydes and ketones structurally different? Find the deviation produced by reflection at a plane mirror when the angle between the incident and reflected rays is 80°. What is meant by aerosol? Calcium is an element with atomic number 20. (a) Is it a metal or non-metal? (b) Is it more reactive than Mg or less? (c) What will be the formula of its Chloride? (d) What will be its valency? Why are asexually reproducing organisms capable of showing the hereditary features more? Whatever may be the position of an object, the image appears to be erect. Give the nature of mirror with reason. Compare and contrast the arrangement of elements in Mendeleev’s Periodic Table and Modern Periodic Table. (a) How do you calculate the valency of an element from its electronic configuration? (b) What is the valency of magnesium with atomic number 12 and chlorine with atomic number 17? (c) What is the difference in number of shells in magnesium and sulphur? Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks 9. Give a labelled diagram of a pistil showing in it the path of male gametophyte from the stigma to the embryo sac. 10. What is reproduction? How do the following organisms reproduce by asexual methods: (a) Potato (b) Hydra (c) Malarial parasite (d) Planaria 11. What is a sex chromosome? Name the two types of sex chromosomes. Mention the sex chromosomes present in males and females. 12. Explain the importance of variations. 13. This story is often told about the world-famous pianist, Jane who is also known for his passion for personal grooming. He used to use a specially designed mirror for shaving. He was once asked by a fellow musician if he could be ready, at very short notice, to take over and play a difficult piece of music at a concert because the pianist who was supposed to play had suddenly fallen ill. “I am always ready. I have practiced eight hours every day for forty years to be ready,” replied Jane. The pianist said, “I wish I had been born with such determination.” Jane replied, “We all are born with it. I just use mine.” Read the above passage and answer the following questions: (a) What kind of mirror is used by Jane for shaving? (b) Draw the ray diagram to show the formation of image by this mirror to focus the bright image os sun at paper sheet. (c) What values are shown by Jane? [Value Based Question] 14. Establish the relation between object distance, image distance and radius of curvature for a convex mirror. 15. Find the position of an object which when placed in front of concave mirror of focal length 20 cm produces a virtual image, which is twice the size of object. 16. How can we make a white light to emerge out as white light from an arrangement of prisms? 17. Explain how carbon di-oxide and ozone layer of the atmosphere are important to life? 18. What changes can you make in your habits to become more environment friendly? 19. Write the electronic configuration of atoms of: (a) Potassium (K) (b) Lithium (Li) (c) Fluorine (F) (d) Chlorine (Cl) Use these electronic configuration to explain why Potassium is more reactive than Lithium and Fluorine more reactive than Chlorine? Or Explain the terms: (a) Atomic radius (b) Ionization energy (c) Electron effinity Mention the units in which they are measured. How do they generally vary (i) in a group, (ii) in a period? Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks 20. (a) Draw electron diagram of (i) N2, (ii) O2, (iii) CaCl2, (iv) Na2O (b) Write IUPAC name of (i) CH3COCH3, (ii) CH3CH2CH2CHO. (c) How will you test the presence of carboxylic acid? (d) Complete the following action: CH3CH2OH + Na → Or An organic compound ‘A’ is widely used as a preservative in pickles and has a molecular formula C2H4O2. This compound reacts with ethanol to form a sweet smelling compound ‘B’. (a) Identify the compound ‘A’. (b) Write the chemical equation for its reaction with ethanol to form compound ‘B’. (c) How can we get compound ‘A’ back from ‘B’? (d) Name the process and write corresponding chemical equation. (e) Which gas is produced when compound ‘A’ reacts with washing soda? Write the chemical reaction. 21. Pea plants with round and green seeds are crossed with wrinkled and yellow seed bearing pea plants. On the basis of Mendelian experiment, what do you conclude from this experiment? Or Explain that it is a matter of chance whether a couple will give birth to a boy or a girl. 22. (a) Vegetative propagation has several advantages. What are they? (b) Mention in detail how sexual reproduction is necessary for evolution. Or (a) Draw a labelled diagram of a pistil showing double fertilization. (b) Which part of Bryophyllum can be used for vegetative propagation? Mention two advantages of vegetative propagation. 23. (a) It is desired to obtain an erect image of an object, using a concave mirror of focal length 20 cm. (i) At what should be the range of distance of the object from the mirror? (ii) Will the image be bigger or smaller than the object? (iii) Draw a ray diagram to show the image formation in this case. (b) One half of a convex lens of focal length 20 cm covered with a black paper. (i) Will the lens produce a complete image of the object? (ii) Show the formation of image of an object placed at 2F1 of such covered lens with the help of a ray diagram. (iii) How will the intensity of image formed by half-covered lens compare with non-covered lens? Or Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks (a) A convex lens of focal length 20 cm can produce a magnified virtual as well as real image. Is this a correct statement? If yes, where shall be the object be placed in each case for obtaining these images? (b) Light enters from air to glass having refractive index 1.50. What is the speed of light in glass? [The speed of light in vacuum is 3 x 108 ms-1] 24. (a) “A ray of light incident on a rectangular glass slab immersed in any medium emerges parallel to itself.” Draw labelled ray diagram to justify the statement. (b) Mention the types of mirrors used as (i) rear view mirrors, (ii) shaving mirrors. List two reasons to justify your answer in each case. Or (a) An object of height 6 cm is placed perpendicular to the principal axis of a concave lens of focal length 5 cm. Use lens formula of determine the position, size and nature of the image if the distance of the object from the lens is 10 cm. (b) State the difference in colours of the sun observed during sunrise/sunset and noon. Give explanation for each. Section B 25. Acetic acid was added to a solid X kept in a test tube. A colourless, odourless gas Y was evolved. The gas was passed through lime water, which turned milky. (a) What was concluded? (b) Give chemical equation involved. 26. (a) What does Amoeba eat? (b) What is the shape of Amoeba? 27. If the angle of incident is 45 on a medium of refractive index 2, then find angle of refraction. 28. 2 mL of ethanoic acid was taken in each of the three test tubes A, B and C and 2 mL, 4 mL and 8 mL water was added to them respectively. A clear solution is obtained in: (a) test tube A only (b) test tubes A and B only (c) test tubes B and C only (d) all the test tubes 29. 2 mL of acetic acid was added in drops to 5 mL of water and it was noticed that: (a) the acid formed a separate layer on the top of water. (b) water formed a separate layer on the top of acid. (c) a clear and homogeneous solution was formed. (d) a pink and clear solution was formed. 30. Which of the following produces seeds without fruit: (a) Cycas (b) Rice (c) Fern (d) Grapes Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks 31. Budding involves growth of new organism: (a) Outside the parent body. (b) On the parent body. (c) Inside the parent body. (d) Both (a) and (b) 32. A pair of contrasting characters is called: (a) phenotype (b) genotype (c) allele (d) gene 33. Genetic information is carries out by long chain of molecules made up of: (a) enzymes (b) DNA (c) amino acids (d) proteins 34. When the two opposite surfaces of the slab are not parallel, the emergent angle e and incident i are related as: (b) e > i (a) e = i (c) e < i (d) Depends on the medium index 35. As light IM is incident on the surface PQ as shown, the emergent ray has to be: (a) NA (b) NB (c) NC 36. Select the wrong statement: I. Forests do not provide variety of products. II. Forests have greater plant diversity. III. Forests do not conserve soil. IV. Forests conserve water. The correct option(s) in/are: (a) Only IV (b) I and IV (c) I and III (d) ND (d) II and III Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks