CBSE Science Practice Paper : Set IX
16. What happens when
(i) Methanal is oxidised by ammonical silver nitrate solution. (ii) Cumene is treated with air (iii) Ethene undergoes polymerisation. Write the chemical reactions involved. 3
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17. (i) Derive the formula 1/f = 1/v – 1/u for a lens.
(ii) Define magnification and relate it to/and it. 3
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18. What is solenoid ? Compare it with a bar magnet. How can we identify its field direction ? 5
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19. Define allolropy. Give three allotropes of sulphur. Explain action of heal on sulphur. What happens when (0 carbon is heated with sulphur, (ii) Hydrogen gas is passed through boiling sulphur ?
How will you manufacture sulphuric acid by contact process ? Explain the process giving chemical equations. Give two physical and two chemical properties of H2SO4. 5
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20. Draw a neat labelled diagram of a compound microscope and explain about the magnification of each lens used. 5
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21. Name the transport system in plants and animals. 1
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22. Name the excretory organs of earthworm. 1
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23. How is menarche different from menopause ? 1
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24. Whose theory influenced Darwin ? What did Darwin fail to explain ? 2
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25. Where do you find chiorophyil in the plant body ? What is the site of chlorophyll ?
Justify transpiration as a force promoting the ascent of sap. 2
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26. Differentiate between male and female reproductive system. 3
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27. What is the main difference between sympathetic system and parasympathetic system ? 3
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28. What is emphysema ? Give its symptoms. 3
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29. Draw the structure of a neuron and label all its parts. 3
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30. What do you mean by conservation ? What are the methods for conservation of the environment ? State why. the environmental law are to be enforced ?
(i) Who provided the evidence of DNA as a genetic material ? Mention about the components of DNA.
(ii) Give a detailed description of the structure of a DNA molecule. 2+3
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