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Important Instructions for the

School Principal

(Not to be printed with the question paper)

1) This question paper is strictly meant for the use in School Based Summative Assessment-

II, March-2012 only. This question paper is not to be used for any other purpose except

mentioned above under any circumstances.

2) The intellectual material contained in the question paper is the exclusive property of

Central Board of Secondary Education and no one including the user school is allowed to

publish, print or convey (by any means) to any person not authorised by the Board in this

regard.

3) The School Principal is responsible for the safe custody of the question paper or any other

material sent by the Central Board of Secondary Education in connection with School

based SA-II, March-2012, in any form including the print-outs, compact-disc or any other

electronic form.

4) Any violation of the terms and conditions mentioned above may result in the action

criminal or civil under the applicable laws/byelaws against the offenders/defaulters.

Note: Please ensure that these instructions are not printed with the question

paper being administered to the examinees.

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SUMMATIVE ASSESSMENT – II, 2012

II, 2012

SCIENCE /

Class – X / X

Time allowed : 3 hours Maximum Marks : 80

3 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 of Section-A and all questions of Section-B are to be attempted separately.

(v) Question numbers 1 to 4 in Section-A are one mark questions. These are to be answered in

one word or in one sentence.

(vi) Question numbers 5 to 13 in Section-A are two marks questions. These are to be answered

in about 30 words each.

(vii) Question numbers 14 to 22 in Section-A are three marks questions. These are to be

answered in about 50 words each.

(viii) Question numbers 23 to 25 in Section-A are five marks questions. These are to be answered

in about 70 words each.

(ix) Question numbers 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.

(i)

(ii)

(iii)

(iv)

(v) 1 4

(vi) 5 13 30

(vii) 14 22 50

(viii) 23 25 70

(ix) 26 41

67022

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SECTION-A /

1. Name the main product formed when ethanol is oxidized by an alkaline solution of KMnO4.

KMnO4

2. No rainbow could be observed from the surface of moon by the astronauts. What could be

the possible reason ?

3. Among the given organisms identify the organism that has the maximum energy if we form a

food chain from the following and give reasons for your answer :- Rat, peacock, plants, snake.

4. Why has the Government banned the use of polybags ?

5. (a) Elements F, Cl and Br are in group 17. What is the number of electrons in outermost

shell of these elements ? Give reason for your answer. (b) Write down the electronic configuration of Al and Si. Their atomic numbers are 13 and 14 respectively.

(a) F, Cl Br 17

(b) Al Si 13 14

6. (a) How does the tendency to lose electrons change in a group ?

(b) On which side of the periodic table are metals placed in the modern periodic table ?

(a)

(b)

7. State any two differences between binary fission and multiple fission.

8. More complex organisms can not give rise to new individuals through regeneration. Why ?

9. You are provided with two lenses of focal length 10 cm and 20 cm. Which of the two lenses

would you suggest to obtain greater convergence of refracted light ? Justify your choice.

10 cm 20 cm

10. What is meant by power of accommodation of an eye ? State the role of ciliary muscles in

accommodation.

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11. What is scattering of light ? The colour of Sun looks different at different times of the day.

Why ?

12. List any four human activities responsible for the pollution of river water.

13. List any four ways of conserving fossil fuels.

14. Define a homologous series ? State any two characteristics of a homologous series : Which of

the following belong to the same homologous series ?

C3H8, C3H6, C4H8, C4H6,

C3H8, C3H6, C4H8, C4H6,

15. Group Number

P E R I O D S

1 2 13 14 15 16 17 18

1 X N O P Q R

2 Y

3 Z

Using the given part of the periodic table, answer the following questions (a) Which element in first group has atom of largest size ? Give reason for your answer. (b) What is the valency of element R ? (c) If the number of valence electrons in Y is one, what will be the no. of valence electrons in X and Z ? Give reason for your answer.

Group Number

P E R I O D S

1 2 13 14 15 16 17 18

1 X N O P Q R

2 Y

3 Z

(a)

(b) R

(c) Y 1 X Z

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16. State the reasons for adopting contraceptive methods. List four methods of contraception.

17. In a cross between plants with pink flowers and plants with white flowers the offsprings of F1

generation all had pink flowers. When the F1 generation was self – crossed, it was observed in the F2 generation that out of 100, 75 flowers were pink. Make a cross and answer the following: (a) What are the genotypes of the F1 progeny ? (b) What is the ratio of Pink: White flowers in the F2 generation ?

F1

F1 F2 100 75

(a) F1

(b) F2

18. (a) Explain Geographical isolation.

(b) Giving reasons state whether the following are Homologous or Analogous organs : (a) Wings of birds and butterflies (b) Root of money plant and sweet potato bulbs

(a)

(b)

(i)

(ii)

19. Look at the given picture and write its name after identifying it. Also give its significance.

( 2 points)

20. How is the refractive index of a medium related to the speed of light ?

Light enters from air to diamond having refractive index 2.40. Calculate the speed of light in

the diamond. The speed of light in air is 3108ms1.

2.40 3108ms1

21. List two reasons of using convex mirrors as rear view mirror in vehicles.

An object is placed at a distance of 10 cm in front of a convex mirror of focal length

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15 cm. Find (i) Position and (ii) nature of the image formed.

15 cm 10 cm

(i) (ii)

22. Study the diagram given below and answer the questions that follow.

(a) Which defect of vision is represented in this case ? Give reason for your answer. (b) What could be the two causes of this defect ? (c) With the help of a diagram show how this defect can be corrected using a suitable lens.

(a)

(b)

(c)

23. (i) What is an ester ? Describe an activity with diagram to form an ester. (ii) Describe along with chemical equations, what happens when :

(a) Ethanol burns in air (b) Ethanoic acid reacts with sodium bicarbonate.

(i)

(ii)

(a)

(b)

OR (i) With the help of diagram, explain the mechanism of the cleansing action of

soaps. (ii) Complete the following reactions :

(a) C2H5OH+Na

(b) CH4+Cl2sunlight

(i)

(ii)

(a) C2H5OH+Na

(b) CH4+Cl2

24. Draw a neat diagram of longitudinal section of a flower showing growth of pollen tube and

label on it the following : (i) ovary (ii) style (iii) stigma

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State in brief the functions of these parts.

(i) (ii) (iii)

OR (a) Name the parts of flower which contain germ cells.

(b) What is the difference between self pollination and cross pollination ? (c) Testes are located outside the abdominal cavity. Why ? (d) Fertilization is possible if copulation has taken place during middle of menstrual cycle.

Give reason. (e) What happens when the egg is not fertilized ?

(a)

(b)

(c)

(d)

(e)

25. Draw ray diagrams in the following cases to show the position and nature of the image

formed by a concave mirror when an object is placed.

(i) between pole and focus

(ii) between focus and centre of curvature

(iii) at the centre of curvature

How will the nature and position of image formed change in case (i) and (ii) if the concave

mirror is replaced by a convex mirror ?

(i)

(ii)

(iii)

(i) (ii),

OR Name the type of lens used to obtain.

(i) a magnified and virtual image of an object.

(ii) a diminished and virtual image of an object.

Draw labelled ray diagrams to show the formation of the required image in each of the above

two cases. Which of these lenses could also form a magnified and real image of the object ?

State the position of the object for which this could happen.

(i)

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(ii)

SECTION - B /

26. A student put zinc granules into CuSO4 solution taken in a test tube as shown in figure.

After some time he observes that the colour of the solution changed from : (a) blue to colourless (b) blue to green (c) light green to blue (d) light green to colourless

(a) (b)

(c) (d)

27. Ashok immersed a few iron nails in the solution of zinc sulphate taken in a beaker. After

sometime he observed that. (a) solution became green and nails got corroded (b) solution remained colourless and nails remained unaffected (c) solution became blue and nails got corroded (d) solution became green and white deposit came up on nails.

(a)

(b)

(c)

(d)

28. When the stopper of a bottle containing colourless liquid was opened, the bottle gave out a

smell like that of vinegar. The liquid filled in the bottle is : (a) Hydrochloric acid (b) Sulphuric acid (c) Acetic acid (d) Nitric acid

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(a) (b)

(c) (d)

29. When ethanoic acid is added to solution of substance 'X', a colourless and odourless gas ‘Y’ is

formed. The substance ‘Y’ turns lime water milky. On the basis of these observations it may be concluded that X and Y could respectively be : (a) Sodium bicarbonate and carbon dioxide (b) Sodium bicarbonate and Hydrogen (c) Sodium hydroxide and carbon dioxide (d) Sodium hydroxide and hydrogen

'X' ‘Y’ ‘Y’

'X' ‘Y’

(a)

(b)

(c)

(d)

30. On adding acetic acid to sodium hydrogen carbonate in a test tube, a student would observe

that the acetic acid reacts – (a) slowly with effervescence (b) vigorously with brisk effervescence (c) at a moderate rate without effervescence (d) vigorously but without any effervescence

(a) (b)

(c) (d)

31. Parallel rays from a distant object incident on a convex lens form an image on the screen.

The focal length of the convex lens in the experimental set up is : (a) 5.4 cm (b) 6.4 cm (c) 4.4 cm (d) 4.6 cm

(cm)

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(a) 5.4 cm (b) 6.4 cm (c) 4.4 cm (d) 4.6 cm

32. A student measures the focal length of a concave mirror by focussing a distant building at three different time of the day on a clear sky day. The timings are : T1 : 8 A.M. T2 : 2.00 P.M. T3 : 5.30 P.M.

The student will most likely to get accurate reading at : (a) T1 (b) T2 (c) T3 (d) Same at all time

T1, T2, T3

T1 : 8 A.M. T2 : 2.00 P.M. T3 : 5.30 P.M.

(a) T1 (b) T2 (c) T3 (d)

33.

In the above set up, the focal length of the concave mirror is 4.0 cm. The marks on the scale on which the screen be placed to obtain a sharp image ? (a) at 8 cm (b) at 2 cm (c) at 6 cm (d) at 1 cm

4.0 cm

(a) 8 cm (b) 2 cm (c) 6 cm (d) 1 cm

34. In an experiment on tracing the path of a ray of light through a rectangular glass slab, four

students marked the angle of incidence and the angle of emergence as shown in the diagrams

given below :

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Which student has correctly marked the angles :

(a) A (b) B (c) C (d) D

A, B, C, D (i)

(e)

(a) A (b) B (c) C (d) D

35. An experiment to trace the path of a ray of light through a rectangular glass slab was

performed by four students A, B, C and D. After completion, they arrived at the following interpretation :

(A) < i e r (B) i > e r

(C) i < e < r (D) i e > r

Which student has arrived at correct conclusion.

(a) A (b) B (c) C (d) D

A, B, C, D

(A) < i e r (B) i > e r

(C) i < e < r (D) i e > r

(a) A (b) B (c) C (d) D

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36. The event that first occurs during binary fission in Amoeba is (a) Division of cytoplasm (b) Formation of two daughter cells (c) Division of nucleus (Karyokinesis) (d) Enlargement of nucleus

(a) (b)

(c) (d)

37. Binary fission in amoeba is a type of

(a) asexual reproduction (b) sexual reproduction (c) vegetative propagation (d) Fragmentation

(a) (b)

(c) (d)

38.

From the above diagram depicting budding yeast, identify the stage which can be observed just before the detachment of bud. (a) (A) (b) (B) (c) (C) (d) (D)

(a) (A) (b) (B) (c) (C) (d) (D)

39. After observing the slide of budding in yeast, a teacher asked four students A, B, C, D the type of reproduction involved in budding of yeast. Their responses were ___________ (A) asexual (B) Sexual (C) Both asexual and sexual (D) First asexually but growth of bud is sexual The correct response was given by ___________ (a) (A) (b) (B) (c) (C) (d) (D)

A, B, C D

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(A)

(B)

(C)

(D)

(a) (A) (b) (B) (c) (C) (d) (D)

40. Which of the precautions, given below is not correct and should not be followed to determine

the percentage of water absorbed by raisins

(a) Raisins should be soaked in boiling water.

(b) Dry the soaked raisins with the help of blotting paper before weighing them.

(c) Raisins should be soaked for sufficient time.

(d) Raisins should be clean.

(a)

(b)

(c)

(d)

41. Weight of raisin taken 5 g (say)

Weight of swollen raisins x g

The correct formula to determine percentage of water absorption by raisins is

(a) 5

g100

x (b)

5 g

100

x

(c) 5

100x

x

(d)

5 100

5

x

5 g

x g

(a) 5

g100

x (b)

5 g

100

x

(c) 5

100x

x

(d)

5 100

5

x

- o O o -