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?