II, SUMMATIVE ASSESSMENT II, / SCIENCE CBSETODAY.COM. X / Class X. Time Allowed : 3 hours Maximum Marks : 90

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1 . 2.. II, SUMMATIVE ASSESSMENT II, / SCIENCE X / Class X 90 Time Allowed : hours Maximum Marks : General Instructions :. The question paper comprises of two Sections, A and B. You are to attempt both the sections. 2. All questions are compulsory. All questions of Section-A and all questions of Section-B are to be attempted separately. 4. Question numbers to in Section-A are one mark questions. These are to be answered in one word or in one sentence. Question numbers 4 to 6 in Sections-A are two marks questions. These are to be answered in about 0 words each. 6. Question numbers 7 to 8 in Section-A are three marks questions. These are to be answered in about 0 words each 7. Question numbers 9 to 24 in Section-A are five marks questions. These are to be answered in about 70 words each. 8. Question numbers 2 to 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. 9. Question numbers 4 to 6 in Section-B are questions based on practical skills. Each question is of two marks. Page of 2

2 SECTION-A X C H 6 X A colourless gas X has a formula C H 6. It decolorises bromine water. Identify X and its Write the chemical name. 2 A bacterial cell is different from cells of other organisms. Name the feature which makes it different from others. Mention the action taken by Government to save river Ganga D Sushil went to an eye specialist for check up. He prescribed him to use spectacle lens of 0.D power. Name the defect of vision he is suffering from. Find the focal length of spectacle lens? 2 Compare reuse and recycle, methods for conservation of environment. 6 2 There is a need to ban polythene bags completely. Explain this statement giving reasons. 7 What are oxidizing agents? State any two oxidizing agents. Write one chemical equation using an oxidizing agent. 8 ph ph Why is ethanoic acid named as glacial acetic acid? Why are mineral acids considered strong acids while carboxylic acids are weak? Compare the expected ph value and the change in colour of ph paper in hydrochloric acid and ethanoic acid using universal indicator. 9 (i) A B Page 2 of 2

3 (ii) (iii) (i) The diagrams A and B shows molecules of two types of washing substances. Which one of these are detergent and soap respectively? 0 2 (ii) (iii) Give a reason for your choice. State one disadvantage of using detergents. 2 2 Identify the elements to complete the table : Period Group Element 2 2 In which manner are the set of genes organized in cells of organism? What are the three different ways in which a particular trait may increase in a population? Explain. Study the diagram given below : Page of 2

4 Identify the process. Which organism uses the above method for reproduction? (c) How is the above method different from the process of fragmentation? 4 DNA Some organisms are created from a single parent while some are created by using the DNA content of both parents. Name the processes of reproduction in the two cases. Give examples of organisms which use the above methods of reproduction. (c) Which method out of the above two would be used respectivelyby Hydra and hens for their reproduction? Human beings have eyes and planaria has eyespots. Give one distinguishing feature between eyes and eyespot. Name any one organism other than planaria having eyespot. 6 : (i) (ii) Name the part of eye that : (i) Controls the amount of light entering into eye (ii) Regulates the size of the passage through which light enters Why are we not able to see immediately after we enter a dark hall from a lighted place? 7 0 cm 0 cm 20 cm A 0 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 0 cm. The distance of the object from the lens is 20 cm. Find the position, nature and size of the image formed. 8 Page 4 of 2

5 Over population is leading to over usage of fertilizers and pesticides to increase food production which is harmful to the environment. Now-a-days organic farming is increasing to prevent bio-magnification of chemicals. Rex felt that pesticides do not enter our food grains as they are covered with chaff. His brother Ted disagreed with him as he had read that - these grains have varying amounts of pesticide residues which cannot be removed by washing or other means. How do pesticides and fertilizers affect soil? What is the advantage of organic farming? (c) What is biological magnification? (d) With whom do you agree, Rex or Ted? Give reason. 9 X ( ) Y ( 7) 20 X Y (c) (d) X An element X(atomic no. ) reacts with an element Y (atomic no. 7) to form a monovalent halide. Identify the position of X and Y in group and period in the periodic table. State whether these elements are metal or non-metal? (c) Describe nature of oxide of element X. (d) Draw electron dot structure of the halide. Describe in brief the independent inheritance of two separate traits like shape and colour of seeds of a pea plant. 2 Write the functions of the following in human female reproductive system : Ovary, Oviduct, Uterus How does the embryo get nourishment inside the mother's womb? Explain in brief. Page of 2

6 22 (c) (d). List two characteristics of refraction of light. Define absolute refractive index. (c) Name the physical quantity with which refractive index of a medium can be related. (d) What is meant by the statement that refractive index of water is.? Demonstrate an activity with a well labelled diagram to prove that white light is made up of seven colours. Which colour of light bends least and which one the most whilepassing out from the prism. Also state the reason for the same. 9 m m Write the relation between object distance, image distance, and focus of a convex mirror. What is the relation between radius of curvature and focus of a mirror. How far an objects should be placed from the concave mirror of focal length m in order to obtain an image on the screen 9 m away from the mirror. / SECTION - B ph (c) (d) ph When soap is prepared by cold process, a small amount of Sodium Carbonate is added to : make the soap porous increase the ph (c) make the soap hard (d) decrease the ph (c) (d) Read the following statement and answer the question that follows : During a saponification reaction vegetable oils and animal fats are reacted with sodium Page 6 of 2

7 hydroxide to obtain soap. From amongst the given oils, which oil cannot be used in preparation of soap : Castor oil Mustard oil (c) Mineral oil (d) Rice bran oil 27 0 ml A, B C ml A B C A C A B (c) B C (d) B Sonia took three samples each of 0 ml of water in test tubes A, B, C. She added ml of liquid soap in all of them and shook them vigorously. The setup of the experiment is shown below : A Rain water B Tap water C Distilled water The test tube (s) which will have the maximum length of foam will be : A and C A and B (c) B and C (d) only B 28 cm Page 7 of 2

8 6 0 (c) 8 (d) In the following setup, the focal length of the concave mirror is cm. The mark on the scale on which the screen be placed to obtain a sharp image would be : at 0 cm at 6 cm (c) at 8 cm (d) at cm. 29 A B (c) C (d) D Which of the rays is drawn wrong in the figure given below : A B (c) C (d) D 0 Page 8 of 2

9 (B) (C) (D) (A) (B) (c) (C) (d) (D) Which of the following is the best set up for tracing the path of a ray of light through a rectangular glass slab? (B) (A) (A) (C) (A) (B) (D) Page 9 of 2

10 (c) (C) (d) (D) Which of the following figures has been labelled correctly in an experiment to trace the path of rays of light through a glass prism Page 0 of 2

11 2 (c) (d) Structures that have the same evolutionary origin even though they may now have different structures or functions are said to be : endemic analogous (c) homologous (d) vestigial (c) (d) In an unfolded dicotyledonous seed the placement of cotyledons relative to the embryonal axis is : both towards the left both towards the right (c) one on either side (d) one anterior and one posterior 4 2 Page of 2

12 6 Out of the following list of chemicals, select those which are required to study the prescribed four properties of Acetic acid in the laboratory litmus solutions (blue or red), water, Alcohol, sodium chloride, sodium hydrogen carbonate, calcium hydroxide solution. If you are being asked to observe the permanent slide of the binary fission of Amoeba, then how would you draw the figures of the following two stages? Division of nucleus Division of Cytoplasm I, II III Observe the following incomplete ray diagram for a convex lens Draw the rays I, II and III after refraction and also locate the optical centre of the lens in the ray diagram. -o0o0o0o- 2 2 Page 2 of 2