CBSE Science Sample Paper Set II

Section - A
1. Name the largest component of biogas, 1

2. Why do we use convex mirror for rear-view mirrors in automobiles ? 1

3. Name the major metal used for making bodies of aircraft. 1

4. What is a fuse wire ? Name its constituent materials. 1

5. Give two characters of energy sources. 1

6. Name the model that was proposed to explore fission and give one example of fission reaction. 2

7. Draw a labelled diagram of apparatus for getting wood gas from wood in the laboratory. What name is given to the solid residue obtained? 2

8. Explain how does concentration affect the rate of reaction ?

9. If a 40 W bulb and a 100 W bulb are operated for 4 hours per day in a month of 30 days. Find the energy consumed at 200 volts of supply potential ? 2

10. Write IUPAC name of the following ;
(i) CH₃COCH₃, (ii) CH₃COOC2H5. 2

11. Point out three differences between nuclear reactions and chemical reactions. 3

12. An organic compound ‘X1 is an essential constituent of wine and beer. X is responsible for the intoxication caused by these drinks. Oxidation of ‘X’ yields an organic acid and ‘Y’ is present in vinegar. Name the compounds X and Y and write their structural formula. 3

13. What does the Big Bang theory say about the origin of universe ? 3

16. What is meant by reversible reactions ? Give one example and write the expression for equilibrium constant for this reaction. 3

17. What is E.M. Induction ? Who introduced this phenomena ? Write the rule used to find the direction of induced current. Name any two devices working on this principle.

18. Derive the Len’s formula. Define and relate magnification with object and image distance. If a concave lens of focal length 15 cm forms an image at 10 cm distance from lens. Find the position of object and also find magnification of the lens. 3+2

19. Name the chief ore of aluminium. How will you purify this ore and extract aluminium from this ore? Explain with the help of neat and labelled diagram giving chemical equations for the reactions involved.
OR
Give four differences between soaps and detergents. Why are detergents preferred over soaps ? How will you prepare soap in the laboratory ? 5

20. (a) When three resistors R₁,R₂ and R₃ are connected in (i) Parallel and(ii) Series, find the equivalent resistance. (b) If a potential of V is applied, what is the power in each case. 3+2

Section - B

21. What is the other term for extracellular fluid? 1

22. Which one of the following pollutants of air affect the capacity of blood in human bodies to absorb oxygen from lungs :
NO₂. SO₂, CO, CO₂. 1

23. What are homologous organs ? Give examples. 1

24. What is oil slick ? What is its ill effect ? 2

25. What are biodegradable and non-biodegradable wastes ? 2

26. What is the role of liver in excretion ? 3

27. Mention the functions of (a) GH, (b) ADH and © ACTH. 3

28. Define reproduction. Explain its significance. 3

29. ‘Archaeopteryx is a connecting link between birds and reptiles’. Explain, 3

30. Describe the mechanism of breathing in human. What happens to the rate of breathing during vigorous exercise and why ?