CLASS VIII SCIENCE SA 2 MODEL PAPER

KENDRIYA VIDYALAY SANGATHAN

CHENNAI REGION

COMMON SUMMATIVE ASSESMENT-II

CLASS: VIII                                                                    MARKS: 60

SUBJECT: SCIENCE                                                      DURATIONS: 2:30 HRS

GRNERAL INSTRUCTIONS

1. All questions are compulsory.

2. There is no overall choice. However internal choice has been     provided in all the questions of five marks category only.

3. Q.No.I, II, III, IV carries 01 mark.

4. Q.No. V carries each 02 marks.

5. Q.NO. VI carries each 03 marks

6. Q.No. VII carries each 05 marks.

I. Fill in the blanks given below-                                                1MX5=5M

1. The stage of an embryo when all the body parts can be identified is called___________________________.

2. Petrol and diesel are obtained from a natural resource called ___________________________.

3. The substances which have very low ignition temperature and can easily catch fire with a flame are called ________________________.

4. Time taken by an object to complete one oscillation is called__________________ .

5. Increase in the temperature due to increase in the carbon dioxide gas in the air leads to_________________________.

II.Answer the following in one word or one sentence         1MX5=5M

6. In which female reproductive organ does the embryo get implanted?

7. Name the male hormone responsible for secondary sexual characters?

8. Which zone of a flame does a goldsmith use for melting gold and silver and why?

9. What is the audible range of frequencies for a normal human ear?

10. Name the natural satellite of the earth.

III. Mark the following statements as true (T) or false (F).  1MX5=5M

11. Fertilization is necessary even in asexual reproduction. (   )

12. Endemic species are those species of plants and animals which are found exclusively in a particular area. (    )

13. Kharif crops are wheat, gram, pea, mustard and linseed. (   )

14. Uranus is the farthest planet in the solar system. (   )

15. Sulpher dioxide and nitrogen dioxide are responsible for acid rain.

IV.Choose the correct answer from the given option.          1MX5=5M

16. Which of the following is essential for the production of thyroxin that changes a tadpole to a frog?

(a) Sodium              (b) Iodine              (c) Nitrogen                  (d) Oxygen

17. Separating of the grains from the chaff is called

(a) Sowing             (b) irrigation          (c) threshing              (d) Harvesting

18. In which of the following materials speed of sound is maximum?

(a) Iron                (b) Air                       (c) fresh water             (d) sea water

19. The splitting of white light into its seven constituents colours is   called

(a) Dispersion (b) Reflection (c) Refraction (d) Rectilinear propagation

20. Unburnt carbon particles in air are dangerous pollutants causing

(a) Respiratory problems     (b) weakness    (c) hair fall    (d) All of these

V. Answer the following                                                             2MX 6=12M

21. Explain burning of fuels leads to harmful products.

22. Give two differences between Kharif crops and Rabi crops.

23. Define amplitude and frequency of a vibration of sound.

24. Explain why a charged body loses its charge if we touch it with our   hand.

25. Write two laws of reflection.

26. Give two differences between asteroids and Comets.

VI. Answer the following                                                             3MX 6=18M

27. Define fertilization. Differentiate between internal and external fertilization.

28. Write short notes on the following:

(i) Coke

(ii) Coal tar

(iii)Coal gas

29. A pendulum Oscillates 80 times in 8 seconds. Finds its time period and frequency.

30. (i) Differentiate between Fertilizer and manure.

      (ii) List three states in India where earthquakes are more likely   to strike.

31. Draw a sketches to show the relative positions of prominent stars in      (i) Ursa Major                    (ii) Orion.

32. Water is one of our most precious commodities and no life can survive without it.It has been predicted that water scarcity will become the subject of wars in the near future. Write any two ways in which water is getting polluted? Write any two measures to stop water pollution at your level.

VII. Write detailed answer of the following                             5MX2=10M

33. (i) What is earthling?

      (ii) Explain how lightening conductors protect tall structures from damage due to lightning?

(iii) Suggest any two measures to protect ourselves due to lightening.

                                               (Or)

(i) Draw neat and labeled diagram of human ear.

(ii) List any two sources of noise pollution in your surroundings.

(iii)Explain in what way noise pollution is harmful to human.

34. (i) Draw a labeled sketch of the human eye.

  (ii) ‘Vision’ is one of the wonderful gifts given to us by God. But most of the people never take care of the eyes. Care for eyes should be taken.  Suggest two methods for proper eye care.

                                      (Or) 

(i)Draw a labeled sketch of different zones of candle flame.

(ii) In an experiment 9.5 kg of a fuel was completely burnt. The heat produced was measured to be 480,000 KJ.Calculate the calorific value of the fuel.