CBSE Class 10 Science Sample Paper 2012 Set 08

SECTION A

1) Among the following which one have aa triple covalent bond ?

          C₂H₆ , C₃H₄ , C₄H₁₀ 

2) Mention the most easy method to detect water pollution ? 

3) Name any two oxidizing agents for alcohols? 

4) An object 2cm in size is placed 30cm in front of a concave mirror of focal length 15cm. At what distance from the mirror should a screen be placed in order to obtain a sharp image? 

5) (a) What is meant by power of accommodation of eye? (b) How does focal length of the eye lens change when we shift looking from distant object to nearby object? 

6) Distinguish between food chain and food web? 

7) Why do we seek construction of dams? Mention any two problems faced with the construction of large dams? 

8) Write the structural formula of the following and state whether these are isomers with reason?  

(a) 1 – butyne    (b) 2 – butyne 

9) (a) Why ethene decolourises bromine water, but ethane not. (b) Write down the relevant chemical equation involved in decolourisation? 

10) Based on the behaviour towards light how substances can be classified? Give one example of each? 

11) Describe three methods of plant propagation which are commonly used for growing garden plants? 

12) Draw a heat labeled diagram of longitudinal section of a typical flower? 

13) (a) Write the electronic configurations of the following elements? Oxygen, Magnesium

      (b) Among O^2- ion and Mg²⁺ ion, which one have larger size and why?

14) Mention any three purposes of using lens combinations in optical instruments?

15) What are the consequences of ozone layer depletion? (Any three) 

16) What is meant by dispersion of white light? Draw a ray diagram to show dispersion of white light by a glass prism? Why do we get different colours? 

17) Energy flow in the biosphere is unidirectional. Comment on the statement

Please refer to attached file for CBSE Class 10 Science Sample Paper 2012 Set H