i. Name two gases, other than carbon-dioxide, that is given out during the burning of fossil fuels and contributes towards acid rain formation.
ii. 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?
OR
i. Why are many thermal power plants set up near coal or oil fields?
ii. Justify in one sentence that hydropower (hydel electricity) is a renewable source of energy.
(i) The two gases other than carbon-dioxide, that are given out during the burning of fossil fuels are sulphur dioxide (SO2) and Nitric oxide (NO). These gases contribute towards acid rain formation.
(ii) The solar cooker which is covered with plane glass slab will work more efficiently as the glass slab will allow the sunlight to enter in it, but will not allow heat to escape from it. It would thus, increase the temperature of the solar cooker and the food item will be cooked more quickly.
OR
(i) Transmission of electricity is more efficient as compared to the transportation of coal or oil over the same distance. This is the reason why thermal power plants are set up near coal or oil fields.
(ii) As water is a renewable source of energy, the electricity generated by water (hydropower) is also a renewable source of energy. It is a type of energy which uses the water stored in dams, as well as flowing in rivers to create electricity in hydropower plants.