1 MARK QUESTIONS
Q1. How is the slurry left in a bio-gas plant in the end, used?
Q2. Name any two elements that are used in fabricating solar cells.
Q3. What are the causes of ocean thermal energy?
Q4. What is the major problem in harnessing nuclear energy?
Q5. List two characteristics of a good source of energy.
Q6. Mention any two limitations of using fossil fuels.
Q7. Name the two major components present in the left-over slurry of a biogas plant.
Q8. Why is a solar cooker painted black from outside?
Q9. Mention the main purpose of using a plane mirror in solar cookers.
Q.10. Mention two different ways of harnessing energy from ocean.
Q11. Write the energy conversion that takes place in hydropower plant.
Q12. State the reason tor considering fossil fuels as non-renewable sources of energy.
Direction (Q.No. 13-17)In each of the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as
(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
(c) If Assertion is true, but Reason is false.
(d) If Assertion is false, but Reason is true.
(e) If Assertion and Reason both are false.
Q13. Assertion: Many thermal power plants are set up near coal or oil fields.
Reason: It is more efficient to transmit electricity than to transport coal or petroleum over the same distance.
Q14. Assertion: In a wind energy farm, a number of windmills are erected over a large area.
Reason: The energy output of a single windmill is large and can be used for commercial purposes.
Q15. Assertion: The slurry left behind is removed periodically and used as excellent manure, rich in nitrogen and phosphorous.
Reason: The large-scale utilisation of bio-waste and sewage material provides a safe and efficient method of waste-disposal besides supplying energy and manure.
Q16. Assertion: Our energy requirements increase with our standard of living.
Reason: The only way to manage energy demand is to produce more energy.
Q17. Assertion: Solar cells can be used to solve energy needs of areas which are not near the source of Electricity production.
Reason: The use of Solar cells is not widespread because of their high cost.
Q18. Which one of the following sources of energy was most common in ancient times?
Q19. Why is bio-gas considered an excellent fuel?
(a) It burns without smoke
(b) It leaves no residues
(c) Its heating capacity in high
(d) All of the above
Q20. Which of the following sources of energy is a conventional source of energy?
(c) Fossil fuel
Q21. Which of the following chemical elements is used for making solar cells?
3 MARK QUESTIONS
Q1. What is a nuclear waste? What are the hazards of nuclear waste to living things?
Q2. Out of two solar cookers, one was covered by a plane glass slab and the other was left open. Which of the two solar cookers will be more efficient and why?
Q3. People living on hills often get sunburns on their skin. Which component of sunlight is responsible for this effect? Why is this effect generally not observed near sea level?
Q4. Increasing demand of fossil fuels has caused harm to our environments. List its three ill effects (disadvantages). Suggest three measures to reduce the consumption of fossil fuels.
Q5. Compare the advantages of generating energy from bio-mass than getting it from hydropower plant?
Q6. Define the process of nuclear fission. Write the steps involved in generating electricity in a nuclear reactor.
Q7. Explain the principle and working of a biogas plant.
Q8. Draw a neat diagram of a biogas plant and label
(i) inlet of slurry,
(ii) digester and
(iii) gas outlet.
Q9. (a) List any two criteria for selecting a good fuel.
(b) Explain how does burning of fossil fuels cause air and soil pollution.
Q10. ‘What is a good source of energy?
Q11. State the energy transformation taking place at hydropower plants. List two advantages of setting up hydropower plants.
Q12. Explain generation of electricity in a thermal power plant.
Q13. What is biomass? What can be done to obtain bioenergy using biomass?
Q14. Why is there a need to harness non-conventional sources of energy? Give two main reasons.
Q15. On what basis would you classify energy sources as
(a) renewable and non-renewable?
(b) exhaustible and inexhaustible?
Are the options given in (a) and (b) the same?
Q16. What is geothermal energy? How can it be used commercially? List in tabular form three distinguishing features between a thermal power plant and a geothermal power plant.
Q17. Mention why is it not possible to make use of solar cells to meet all our energy needs. State three reasons to support your answer.
Q18. (i) Write four characteristics used for selecting a suitable fuel.
(ii) ‘Gaseous fuels are preferred over solid fuels in chemical industries’. Comment.
Q18. State in brief the process of harnessing kinetic energy of the wind. Mention some limitations of harnessing wind energy on large scale.
Q19. (i) State one limitation of using solar energy available from solar cells.
(ii) What is’ the minimum wind velocity required to obtain useful energy from a windmill?
(iii) Define the term nuclear fission.
5 MARKS QUESTIONS
Q1. The Government of Delhi and Delhi Transport Corporation (DTC) have converted passenger buses into CNG based vehicles. Give reasons for such a decision. ls CNG an ideal fuel according to you? Comment.
Q2. What are the environmental consequences of using fossil fuels? Suggest the steps to minimise the pollution caused by fossil fuels which causes global warming.
Q3. (i) Describe the steps involved in obtaining bio-gas and explain what is meant by anaerobic decomposition.
(ii) Which isotope of uranium can undergo fission readily?
Q4. A student has setup a model of box-type solar cooker. He used a black translucent plastic sheet to cover the open face of the box. He found that this cooker does not function well. What modification should he make to enhance its efficiency? Give reason. Mention the maximum temperature that can be reached in a box-type solar cooker.
Q5. A certain form of energy is available due to the difference in the temperature of water at the surface of the ocean and its deeper levels.
(i) Name the form of energy.
(ii) Is this energy ultimately derived from the sun or not?
(iii) Explain, how this form of energy can be converted into electricity?