CBSE Guess > Papers > Important Questions > Class X > 2009 > Science > Science By Mr. Siddhartha Dixit

CBSE CLASS X

Q. 1. Name three forms in which energy from oceans is made available for use. What are OTEC power plants? How do they operate?

Q. 2. Why is tidal energy not likely to be the potential source of energy?

Q. 3. With the help of labeled diagram explain the principle of working of windmill. Name two places in India where wind energy is being used to generate electricity.

Q. 4. Name the major fuel component of biogas. What are its combustible components? Draw a simple labeled diagram of a fixed dome type biogas plant. What is the use of residual slurry and why?

Q. 5. Why is charcoal considered as better fuel than wood? Give two reasons.

Q. 6. Name two components obtained by fractional distillation of petroleum that are not used as fuel.

Q. 7. Name the places in our country where fields of natural gas are found. Why is it called a clean fuel? Give two reasons.

Q. 8. How are fossil fuels formed? How these fossil fuels were made?

Q. 9. Define calorific value of a fuel? Why is calorific value of CH4 higher than that of Butane?

Q. 10. The heat produced on complete combustion of 10g of fuel could raise the temperature of 2Kg of water from 20 0C to 70 0C. Calculate the calorific value of the fuel if the specific heat of water is . Assume that the heat taken by the container is negligible. How is biogas prepared? Give its composition is 40KJ/g. Calculate the amount of biogas required to produce 1000KJ of energy.

Q. 11. One gram of coal on complete combustion produces 30KJ of energy. The chulha used for combustion has an efficiency of 20%. If 5.6gm of coal is used to heat ‘W’ grams of water from 15 0C to 35 0C. Calculate ‘W’. ( Specific heat of water 4.2J/g0C)

Q. 12. Write four characteristics for selecting a suitable fuel.

Q. 13. What is a Solar cell? Name two materials mostly used in making solar cell.

Q. 14. For producing electricity the energy from flowing water is preferred to energy obtained from burning coke. State two reasons for it.

Q. 15. With the help of a diagram explain how the design of box type solar cooker ensures minimum loss of heat from its inside.

Q. 16. Electricity generated from windmill/oceans is another form of solar energy. Explain.

Q. 17. One gram of coal on complete combustion gives 18KJ of heat. Calculate the amount of coal required to liberate the same amount of heat that an electric heater 2KW provides in one hour.

Q. 18. Why does it take longer to burn wet wood/ log large in size?

Q. 19. What is meant by refining of petroleum? Draw a labeled diagram petroleum distillation tower. Why CNG is considered an environment friendly fuel?

Q. 20. What do you mean by combustion of methane? List the three essential requirements for any combustion to take place.

Q. 21. What is the main constituent of petroleum gas?

Q. 22. How much solar energy will be received 1m2 area in one hour if the solar constant was 1.6 KW/m2?

Q. 23. Describe the construction and working of solar cooker.

Q. 24. When kerosene is used in a stove it produces a blue flame whereas in a kerosene-lantern it produces a yellow flame. Give reasons.

Q. 25. It is very difficult to use hydrogen as a source of energy although its calorific value is quite high. Explain.

Q. 26. Define Solar constant.

Paper By Mr. Siddhartha Dixit